CA1204570A - Method and apparatus for manufacturing magnet wire - Google Patents
Method and apparatus for manufacturing magnet wireInfo
- Publication number
- CA1204570A CA1204570A CA000435917A CA435917A CA1204570A CA 1204570 A CA1204570 A CA 1204570A CA 000435917 A CA000435917 A CA 000435917A CA 435917 A CA435917 A CA 435917A CA 1204570 A CA1204570 A CA 1204570A
- Authority
- CA
- Canada
- Prior art keywords
- die
- entrance
- exit
- filament
- conductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
A method and apparatus for applying a coating to a conductor in a single pass, to produce magnet wire with a coating having favourable concentricity and continuity characteristics. The apparatus includes an entrance die, an exit die and a die block therebetween, The entrance and exit dies include a throat portion and an entrance opening larger than the throat portion. The die block has an interior passage forming a die chamber which is filled with flowable hardenable material under pressure, from a reservoir. Pay-out and take-up devices are adapted to feed wire through said entrance die, said die passage and hence through said exit die. Upon the wire entering the die apparatus the converging interior wall provides a surface adjacent to which the material creates a support of coating material such that the wire does not contact the die and the wire is centered in the die throats and forms a continuous and concentric layer of coating on the wire.
Description
57~
BACKGROUND OF THE INVENTION
The invention relates to magnet wire and a method and apparatus for manufacturing magnet wire, and more particularly, to a method and apparatus for applying a coating of flowable resin material on a continuously moving filament to a desired thickness in a single pass.
Magnet wire has been conventionally manufactured by passing a bare copper or aluminum conductor or a previously insulated copper or aluminum conductor through a bath of liquid enamel (a solution of resin material in a solvent thereof) and through an oven for driving off the solvent from the enamel and/or curing the resin, leaving a resin coat on the conductor.
The application of a coat of materîal to a filament from solution accounts for all of the magnet wire manufactured today. While some materials using today's technology can only be applied from solution, the cost ox the solvent expended in applying resin materials from solution is usually significant. The machinery used in this process is also higly complex and expensive, although the machinery cost is usually not a factor since most of such machinery has been in use for a considerable number of years. Still the original cost of such machinery is significant for new installations In addition to the cost of machinery and the solvent expended by such a process, there is the cost of providing and maintaining pollution control equipment;
since recently both Federal and State laws have required that the oven stack gases of such machines be essentially stripped of solvent beEore exhausting the gases to the atmosphere While various methods of 7~
burning the vaporized solvent and/or reclaiming the solvent have been proposed, all such methods result in further expense to the manufacturer.
Additionally, the application of a layer of material to a filament from solution usually requires several successive coats in order to result in a concentric coat of a desired thickness. For example, six coats may be required for a 3 mil coating, although in specific applications as many as 24 coats have been required. Also, multiple coats of certain materials cannot be applied successfully from solution due to a lack of good adhesion and wetting between coats.
It therefore has been desirable for some time to provide an improved method of manufacturing magnet wire which eliminates the use of solvent. Also, it would be additionally highly desirble to provide an improved method of manufacturing magnet wire which would utilize an apparatus of simple design. Also, it would be highly desirable to provide a method of manufacturing magnet wire which would allow the wire to be drawn coated and spooled in a continuous operation; conventionally the wire is drawn, annealed if necessary, spooled; and then coated and spooled again for shipment. Additionally, it would be highly desirable to provide a method and apparatus which can successfully apply multiple layer of materials which have heretofore not been possible.
Finally, it would be highly aesirable to provide an improved method and apparatus for manufacturing magnet wire which would not require the use of solvent or pollution control apparatus, or be limited to materials requiring an oven cure, or require multiple coats to obtain a coating of the required continuity and concentricity.
Applying coatings of resinous material by extrusion is substantially less common than applying coatings from solution, since conventional extrusion processes are extremely limited. Coatings of 4 mils and less are either extremely difficult to apply or impossible to apply by conventional extrusion processes. Also, the number of materials which are successfully applied by conventional extrusion processes are extremely limited.
Polyvinyl chloride, polyethylene, polypropylene and various elastomeric rubbers comprise 99% of the materials applied by extrusion. These materials are not used in a true magnet wire application, ire. an electrical winding, the turns of which are insulated to provide low voltage, mechanical and thermal protection between turns, and do not possess magnet wire properties. In contrast, these materials are conventionally used in lead wire or hook-up wire applications which must protect against the full imput line voltage of an electrical device. Conventionally, extrusion is used in the production of only cables, building wire, and lead or hook-up wire.
While the apparatus used in conventional extrusion processes is relatively simple when compared to a conventional wire coating tower, and the extrusion process can be carried out continuously whereby the filament may be drawn, coated and spooled in a continuous operatlon, still, a conventional extrusion apparatus is not without problems. Conventional extruders include a centering die, a material reservoir and a sizing die. The centering die mechanically centers the filament in the sizing die, the sizing die determines the exterior dimensions of the coated filament and the thickness of the coat applied to the filament. The primary problem associated with extrusion apparatus is the wear on the centering die. Since the centering die used to center the filament within the sizing die, the centering die must be finely adjusted to achieve a concentric coating and must be replaced periodically due to the wear resulting from the contact between the filament and the die. Centering dies tend to be expensive even when made of hardened steel, but because of the wear that occurs, diamond centering dies have been considered, but not widely used.
Therefore -it would be highly desirable to provide an improved method and apparatus for manufacturing magnet wire which would have all of the benefits of an extrusion process but none of the disadvantages. Such a method and apparatus would lower the cost of the machinery to manufacture magnet wixe and would eliminate the need for solvent, lower manufacturing costs, conserve raw materials and energy, eliminate the need for pollution control apparatus, require less expensive and simpler machinery than now is conventional, and allow for continuous operation from wire drawing to final shipment without being limited to materials from solution or oven cures.
SUMMARY OF THE INVENTION
It is therefore a primary object of this invention to provide an improved method and apparatus for manufacturing magnet wire.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire which does not require solutions of insulation material and thereore eliminates the need for solvents pollution control equipment or for 5~7~
reclaiming solvents from the manufacturing process, lowers the cost of manufacturing at least proportionally to the cost ox solvent, and conserves energy at least to the degree what energy is required to remove solvents from the insulation material.
It is also another object of this invention to provide an improved method and apparatus for manufacturing magnet wire which is not limited to the use ox insulation material solutions or materials requiring curing after application.
It is another object of this invention to provide a method and apparatus for manufacturing magnet wire which does not require multiple coats to obtain the required concentricity and/or continuity.
It is another object of this invention to provide an improved method and apparatus for manufacturlng magnet wlre in which a coating materîal Jan be applied to a continuously moving elongated filament to a desired thickness in a single pass.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire my which magnet wire can be manufactured at speeds which are limited only by filament pay-off and take-up devices It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire by which a coat of resin material may be applied to an elongated continuously moving filament to a desired single thickness in a single pass whereby the filament may be drawn or otherwise formed/ coated and spooled in a continuous operation.
It is another object of this invention to provide an improved method and apparatus for manuacturing S'~ [3 magnet wire which completely eliminates or substantially reduces the use of solvents thereby eliminating the cost of solvents and the need for pollution control equipment or to reclaim the solvents from the manufacturing proces 5 .
It is another object of this invention to provide an improved method and apparatus for rnanufactur.ing magnet wire which completely eliminates the need of highly complex machinery or dies which experience high wear and must be replaced periodically.
It is another object of this invention to provide an improved method and apparatus of manufacturing magnet wire which has all of the advantages of a conventional extrusion process but i5 not limited in the thinness of the coating applied to the filament by such a process.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire having all of the advantages of a conventional extrusion process but none of the disadvantages.
In the broader aspects of the invention, there is provided a novel method an apparatus for manufacturing magnet wire in a continuous process by which coatings of a flowable resin material may be applied concentrically to a moving elongated fil ment in thicknesses of about 16 mils or less. The filament can be a bare copper or aluminum conductor having round or rectangular configuration ox an insulated conductor upon which a top or an intermediate coat of material is desirably applied Coatings of one-half mil and one mil also can be applied by the method of the invention D By the method and apparatus of he i.nvention, magnet wire can be manufactllred by continuously drawin9 the wire to 7~
size, annealing -the wire, if necessary, insulating the wire wi-th one or more coa-ts of flowable resin material, curing the resin material, if necessary, hardening the resin ma-terial, and spooling the wire for shipment, wi-thout interruption a-t speeds limited only by -the filament pay-off and -take-up devices used. The apparatus oE the invention utilizes the flowable resin material to center the filamen-t in a die, -the size of the die controls the thickness of the coat to be applied. In the apparatus of the invention, only the resin material beiny applied to the filament is in contact with the filament. Thus, the mechanical wear normally associated with centering dies used in extrusion processes and like devices is completely eliminated. Further, -the apparatus and method of -the invention can be used to apply coats several times thinner than is possible with conventional extrusion apparatus and of materials different than those conventionally extruded onto filaments.
In specific embodiments using heat softenable materials or melts, curing is no longer required; and -thus, the need for curing, ca-taly-tic burners and the like as well as all concerns regarding atmospheric pollution are eliminated The coa-ted filaments and magnet wire made by the apparatus and in accord-ance with the method of the inven-tion have coatings which are surprisingly conce~ricand continuous when compared to magnet wire made by conventional methods and apparatus In accordance wi-th the present invention, there is provided a method of manufacturing magnet wire in which a flowable bu-t hardenable matexial is applied to an elongated conductor to a desired thickness in a single pass whereby said conduc-tor may be drawn or otherwise formed, coated and spooled in a continuous operation comprising the s-teps of:
a. passing said conduc-tor -through a stationary entrance die at a speed in excess of 100 fee-t per minute, , 7~3 b- passing said conduetor through a stationary exit die at a speed in excess of 100 feet per minute, said exit die having a throat portion, an entrance opening larger than said throat portion intereonneeted by a eonverging interior wall -thereby defining a die eavity between said throat portion and said opening and said conduc-tor and said wall, said entrance die and exit die defining and partially enclosing a die chamber therebetween, said eonductor in said dies being spaced from said dies, e. filling said die chamber with a flowable material including less than about 5% weight solvent at a temperature above the melting point thereof, d. raising the pressure of said material within said die ehamber above atmospheric pressure, e. passing said eonduetor through said die chamber thereby applying said flowable material onto said conductor, f. centering said conductor in said throat portion of said exit die solely with said material in said die chamber, g. wiping the exeess of said material from said eonduetor leaving an essentially eoneentric coat of said ma-terial on said conduetor of a thickness meeting the requirements of ANSI/NEMA Standards Publication No. MW1000-1977.
In accordance with another aspect of the invention, there is provided an apparatus for the manufacture of magnet wire eomprising a die apparatus, a filament pay-out deviee, a eoated filament take-up deviee, said die apparatus being loeated between said pay-out and take-up deviees, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion intereonnected by a converging interior wall - 9a --.,!,~. ', so and an exi-t opening larger than said -throat portion inter-connected by a diverging interior wall, said exi-t die haviny a throa-t portion, and an entrance opening larger than said throat portion in-terconnected by a converging interior wall, said die block having an interior passage communicating wi-th said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber between said diverging interior waLl and said passage and said converging interior wall, said entrance and exit dies being positioned to receive a filamen-t trained between said pay-out and take-up devices in said openings and tnroat portions thereof; a reservoir of flowable but hardenable material, means operatively connected to said reservoir for filling said central die chamber with said material and maintaining said material wi-thin said die chamber at elevated pressures, and means including said ma.terial in said die chamber for cen-tering said filament in said throat portion of said dies.
In accordance with another aspect of the invention, there is provided an apparatus for the manufact:ure of coated filaments such as magnet wire comprising a die apparatus, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging in-terior wall and an exit opening larger than said throa-t portion interconnected by a diverging interior wall, said exit die having a -throat portion, and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an in-terior passage communicating with said exi-t opening of said entrance die and said entrance opening of said exit die thereby defining a flowable material centering - 9b - . "
5~3 chamber between said diverging interior wall and said passage and said converging interior wall.
In accordance with another aspect of the invention, there is provided an apparatus for the manufacture of coated filaments such as magnet wire comprising: a bare filament pay-out device, a coated filament take-up device, and a die apparatus loca-ted between said pay-out and take-up devices, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion and an entrance opening and an exit opening larger than said throat portion, said throat portion connected to said entrance opening and interconnected by a diverging interior wall to said exit opening, said exit die having a throat portion and an exit opening and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage communicating wi-th said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber between said diverging interior wall and said passage and said converging interior wall, an applicator means, connected to a reservoir of coating material, for filling said die chamber with said coating material at a desired pressure, upon said filament entering said die apparatus said converging interior wall providing a surface adjacent to which said material creates a support of coating material such that the filament does not contact the die and the filament it centered in said die throats and forms a continuous and concentric layer of coating material on said filament.
BRIEF DESCRIPTION OF TIIE DRAWINGS
The above mentioned and other features and objects , . .
5~7~
of this invention and the manner of attaining them will become more apparent and the invention itself will be - 9d -5~
best ~lnderstood by reference to the following description of the invention taken in conjunction with the accompanying drawings wherein:
Fig. 1 is a perspective, fragmentary and diagramatic view of the apparatus of the invention;
Fig. 2 is a cross sectional view of the coating die of the invention, taken substantially along the Section Line 2-2 of Fiy. 1;
Fig. 3 is a front plan view of the coating die of the invention taken substantially along the Section Line 3-3 of Fig. 1; and Fig. 4 is a cross-sectional view of the coating die of the invention taken substantially along the Section Line 4-4 of Fig. 2.
DESCRIPTION OF A SPECIFIC EMBODIMENT
., . - _ APPARATUS
Referring to the drawings, and specifically Fig. 1, the apparatus of the invention will be descried. The apparatus 10 generally consists of a filament pay-out device 12, a filament heater 14, a coating material dispenser 16, a coating die 18l a hardener 20, and a filament take-up device 22. As shown in Fiy. 1, the filament 24 is broken at 26, at ~B, and at 30 . At the filament break 26, when the apparatus of the invention is used to manufacture magnet wire, conventional wire drawing apparatus may be insertedO Thus, an oversized filament 24 may be reduced to the desired size by the drawing equipment prior to coating the filament. The filament heater 14 in a specific embodiment in which magnet wire is being manufactured by the apparatus of the invention may include an annealer whereby the 4S7~
effects of drawing the wire or stretchlng the wire may be eliminated. In other specific embodiments in which magnet wire is being manufactured by the apparatus of the invention, additional coating dies 18 and hardeners 20 may be inserted at 28 such that successive coats of different coating materials may be applied to the filament in a continuous manner.
The term "filament" is used herein for all strand materials. Filaments thus include both copper and aluminum conductors and insulated copper and aluminum ronductors which prior to the application of a coat of material by the apparatus and method of the invention have been insulated with a base coat of insulating material, a tape of insulating material either spirally or longitudinally wrapped on the conductor, or other conventional insulating materials, and other strand materials desirably coated. While the specific embodiments herein descrlbed primarily relate to the manufacture of magnet wire, the apparatus of the invention is thought to-have-utility in coating all sorts of filaments other than conductors or insulated conductors in the production of magnet wire.
The term "10wable materiall' is used herein for the general class of coating materials applied by the method and apparatus of the invention Again, while the specific embodiments herein described refer to meltable coating materials which can be hardened by cooling the material to ambient temperatures, other coating materials which are flowable at elevated temperatures and pressures are contemplated as being within the general class of materials which can be applied by the method and apparatus of the invention. These materials include materials which are initially flowable but later 5~
hardened by curing or the~mosetting the material and also coating materials which may include up to about 5%
by weight ox solvent to render them flowable and later hardenable by driving the solvent from the material. In the manufacture of magnet wire, several different materials can be applied by the method and apparatus of the invention. These include but are not limited to polyamides such as Nylon, polyethylene terephthalates, polybutylene terephthalates, polyethylenes, polyphenylene sulfide, polycarbonate~, polypropylenes, polyethersulfone, polyether imides~ polyether etherketone, polysulphonesl epoxys, flurocarbons including ethylene-chlorotrifluoroethylene and hylene tetrafluoroethylene polyvinyl formal, phenoxys, polyvinyl butyrol, polyamide-imide, polyesters and combinations thereof.
The filament pay-out device 12 includes a spool 32 on which the filament 24 desirably coated is stored.
The spool 32 is mounted on spindle 34 of the pay-out device 12 so as to freely rotate in the direction of the arrow 36. Operatively associated with the spool 32 is a brake 3~ which restrains the rotation of the spool 32 as the filament 24 is being pulled therefrom by the taXe-up device 22 so as to prevent entanglements. In accordance with the method of the invention, it is highly possible that in a magnet wire manufacturing plant where conductors are being rolled, drawn or otherwise reduced in size to desirable conductor from ingots, the pay-out device 12 can be completely eliminated, since the remaining apparatus can be used to coat conductors continuously in a single pass as the conductor is supplied from such rolling and drawing apparatus The reels 32 in this instance can be the reels upon which bar copper and aluminum conductors are now transported from the rolling and drawing operations to the magnPt s~3 wire manufacturing plants. In all instances where the take-up device 12 is eliminated and rolling and drawing operations are substituted therefore, an annealer is an essential part of the apparatus in order to eliminate the effects of working the conductor during the rolling and drawing operations.
Filament heater 14 is an essential part of the apparatus of the invention to be used in the performance of the method of the invention. A filament heater may be used solely to raise the temperature of the filament prior to the application of the coating material or may be an annealer if hard bare wire is used or to further reduce the effects of the aforementioned rolling and drawing process, if required. Thus, in a specific embodiment, the filament heater 14 may consist of an annealer, or may consist ox a filament heater. In the specific filament heater embodiment 14 illustrated in Fig. 1, the filament heater comprises a resistance coil 40 being generally tubular in shape and having opposite open ends 42 and 44. The filament or conductor 24 is trained between the pay-out device 12 and the tàke-up device 22 through the coil 40. The filament heater 14 is also provided with a control 46 by which the temperature of the conductor 24 can be controlled. The filament heaver 14 may also include a filament temperature measuring device such as a radiation pyrometer. Hereinafter in specific examples, the approximate wire temperatures reported herein are measured by such a device.
The coating die 18 is illustratecl in Figs. 1 through 4. The coating die 18 includes an entrance die 61, an exit die 62 and a die block 64. entrance die 61 is mounted in the forward portion of die block 64 by 5~7(3 screws 66. Exit die 62 is mounted in the rearward portion of die block 64 by screws 66'. Separating entrance die 61 and exit die 62 is an interior passage 65. Die block 64 is provided with heater bores 68 in which heaters 70 are positioned. In a specific embodiment, etch heater 70 may be a tubular calrod heater. Additionally, the die block 69 is provided with a thermocouple bore 72 therein in which a thermocouple 74 (shown only in Fig. 4) may be positioned.
Furthermore, die block 64 is provided with a nozzle bore 75 therein to which the nozzle 54 of material applicator 16 is connected. Hereinafter die temperatures are reported with regard to specific examples; these die temperatures are measured by thermocouple 74~ Heaters 70 are connected by suitable conductors to a heater 76.
seater 76 i5 provided with paired controls 78 whereby the temperature of the entrance vie 61 and the exit die 62 each can be elevated above ambient temperature (for each die) and controlled, respectively, as desired.
eferring to Fig. 2, the entrance die 61 is shown in cross-section to include an entrance opening 80, a throat 82 and a converging interior wall 84 which interconnects the throat 82 and the entrance opening 80 of the entrance die 61. Entrance die 61 also has an exit opening 86 and a diverging interior wall 88 interconnecting the throat 82 and the exit opening 86.
In a specific embodiment, the entrance die 61 can he constructed as illustrated in a two-piece fashion hazing a central piece 90 including a throat portion of harder and more wear-resistant material, and exterior piece 90 which includes both the entrance opening 80 and the exit opening 864 The exit die 62 is also shown in Fross-section to include an entrance opening 92, a throat 93 and a converging interior wall 94 which interconnects the throat 93 and the entrance opening 92 of the exit die 62. Converging interior wall 94 partially defines a die chamber 9S as will be mentioned hereinafter. Exit die 62 also has an exit opening 96 and a diverging interior wall 97 that interconnects the throat 93 and the exit opening 96. In a specific embodiment, the exit die 62 can be constructed as illustrated in a two-piece fashion having a central piece 98 including a throat portion of harder and more wear resistant material than the exterior piece 98' which includes both the entrance opening 92 and exit opening 96.
In a specific embodiment, the converging wall 84 and 94 define an angle A with conductor 24 of about 5 to about 40 degrees and throats 82 and 93 are tapered from converging walls 84 and 94 to diverging wall 88 and 97 so as to define an angle with the conductor 24 of about .
1 to about 2 degrees.
The flo~able material applicator 16 has a chute 48 by which the material is supplied to the applicator, a material reservoir 50 in which the material may be stored, and a positive displacement pump 52 which pressurizes reservoir 50 and dispenses the flowable material through a nozzle 54. When using melts or other temperature responsive flowable materials, reservoir 50 is provided with a heater and a control device 56 by which the temperature of the material in the reservoir can be controlled. An additional control device 58 is associated with the positive displacement pump 52 to control the amount of flowable material passing through nozzle 54. In a specific embodiment, the fluid material applicator 16 may be an extrusion apparatus having the features above described. In those applications in which the flowable material is rendered more flowable by the use of a small portion of solvent, both the coating material and the solvent may be fed into the applicator via the chute 48 and the reservoir 50 may be provided with a mixing apparatus having associated therewith a separate control 60.
The central die chamber 95 is completely defined by the diverging wall 88 of entrance die 61, the converging interior wall 94 of exit die 62, and the walls of interior passage 65 of die block 64. Die chamber 95 is positioned between throat 82 and throat 93. The nozzle 54 is connected to nozzle bore 75 so that coating material in reservoir 50 may be injected into the central die chamber 99 under pressure by material applicator 16. The filament or conductor 24 is trained between the pay-out device 12 and the take-up device 22 through the entranee die 61, the central die chamber 95, and the exit die 62~
The hardener 20 functions to harden the coat of material on the filament or conductor 24 prior to spooling the coated filament or magnet wire by the take-up device 22. the hardener 20 as illustrated includes a trough 100 having opposite open ends 102 and 104. The trough is positioned such that the filament or conductor 24 can be trained to enter the open end 102, pass through the trough 100j and exit the open end 104.
Also as shown, the trough 100 is sloped downwardly toward the open end 102 and provided with a source of cooling fluid, such as waxer 108~ adjacent open end 104 and a drain 110 adjacent open end 132. In many specific embodiments, a water quench uti.lizing tne structure of -the hard-ener 20 is desi:red. In other specific embodiments, a quench is not required and thus, the cooling flllid is no-t used. In these embodiments, ei-ther a flow of ambien-t air or rel-rigerated air (where available) is trained on the coa-ted conductor or filament 24.
In specific embodiments in which multip]e coats of dif-ferent materials are being applied to the filament or conductor 24 by successive spaced apart coating dies 18, the particular coating 10 die used depends on the material to be applied and maybe either the coating die 18 having an entrance die 61 and an exit die 62 as disclosed herein or the coating die disclosed in united States Patent No. 4,393,809. The particular coa-ting die used depends on the material to be applied. Each of the coating dies will have a material applicator 16 associated therewith and may have a hard-ener 20 associated therewith. The term "coating station" is used herein to refer to the assemblage of a material applicator 16, a coating die, and a hardener 20. In these embodiments, there will be a plurality of spaced apart coating stations between the pay-20 out device 12 and the take-up device 22.
The take-up device 22 in many respects is similar to the pay-out device 12. The take-up device 22 comprises a reel 32 on which the coated filament or conductor 24 is spooled for ship-men-t. Thus reels 32 may be the conventional spools on which coated filaments are conventionally shipped. Spools 32 are moun-t-ed for rotation on a spindle 34 so as to be driven in the direc-tion of the arrow 112. Operatively connected to the spool 32 is a spool driver 114 which drives the spool 32 and -thereby pulls the filament or conductor 24 from the spool or reel 32 of the pay-out device 12.
i - 17 -57C~
THE METHOD
The method of the invention will Dow be described.
Reference to Figs. 1 through 4 will be referred to and the terms "flowable materialn and "filament" will be used as above defined. This description of the method of the invention will also specifically refer to the manufacture of magnet wire in a single pass whereby the filament or conductor is drawn or otherwise formed, coated and spooled in a continuous operation.
A continuous supply of the filament or conductor 24 is provided either by the pay-out device 12 as illustrated in Fig. 1 or from a rolling and drawing operation. If supplied from a rolling and drawing operation, the conductor 24 is always annealed to remove all effects of the rolling and drawing operation.
The filament or conductor 24 is then heated, if desired. Whether or not the filament 24-is héated is dependant upon the coating material utilized and the wire properties desired Thus, the filament 24 may be heated by the heating device 14 to a temperature from about ambient temperature to about the decomposition temperature of the coating material. In most applications utilizing a melt or a heat-responsive flowable material in which the coat of material is desirably adhered to the filament or conductor 24, the filament or conductor is heated to a temperature from just below to about the melting point of the coating materialO In most applications utilizing a melt or a heat-responsive flowable material in which the adhesion of the coat of material to the filament or conductor 24 is not required, the filament or conductor 24 is maintained from about the ambient temperature to 51 i~htly abov2 the ambient temperature The central die chamber 99 is then filled with a flowable material. The flowable material is stored in the material reservoir 50 at a flowable temperature and pressure and is injected into the central die chamber 99 by applicator 16. Once the central die chamber 99 has been filled with material, the flowable material contained therein ~7ill assume the pressure of the flowable coating material in the reservoir 50. Pump 52 must have an adequate capacity to maintain pressures up to about 2000 psi in reservoir 50 and chamber 99. By control 58, the responsiveness to pressure changes desired can be controlled. By controls 56 and 78, the temperature of the material in the reservoir 50 and chamber 99 can be controlled. The pressurized temperature of the flowable material in the central die chamber 99 must be carefully controlled for several reasons. First, if the pressure and/or temperature of the flowable material in the central die chamber 99 is too great, the flowable coating material may have the tendency -to leak in significant quantities from the central die chamber 99 through throat 82, although the filament passing through throat 82 will allow operating pressures higher than that at which the flowable material Jill leak from opening 80 when the filament is stationary in opening 80. Any significant leakage of flowable coating ma.erial from the die block 64 is not preferred. Secondly, both the pressure and temperature of the flowable material relate to the viscosity and/or flow characteristics of the flowable material, and must be such that the viscosity and/or flow characteristics of the flowable material performs its centering function relative to the exit die 62 and produces a concentric coating as will be subsequently discussed, wets the filament to be coated, and suitably adheres to the filament. Thirdly, if the pressure and the temperature of the flowable material is too low, excessive filament stretching may occur from die 18 excessively resisting the movement of filament therethrough. It is for these reasons, that the applicator 1G is provided with controls 56, 58, and 60.
The coating material is then applied to the filament or conductor 24 by passing the same through die 1 a . The coating material within the die chamber functions to center the filament or conductor 24 within the throat portions 82 and 93 of dies 61 and 6~. In all instances known to the applicants wherein the central die chamber 99 is properly filled with coating material 115 and the temperature and pressure therein are properly controlled, filaments or conductors 24 that are coated by the method and apparatus of the invention have a surprlsingly concentric and continuous coat of coating material thereon. Conversely, in all situations in which the central die chamber 99 is not properly filled, anon the temperature and pressure therein is not properly controlled, a non-concentric and discontinuous coat of coating material is applied to the filament or conductor 24. Thus, the proper filling of the central die chamber 99 with coating material the control of the temperature and pressure of the coating material therein are essential to the method of the invention. Coating materials of various types have teen successfully applied in accordance with the method of the invention by the above~described apparatus at viscosities from about 5,000 cps to 200,000 cpsO
Applicant does not completely underskand the actions of the flowable material within the central die 3~
chamber 99 which results in filaments having coatings of perfec-t concentricity and continui-ty thereon. The coating material con-tained within the central die chamber 99 is believed to have movement adjacent the throat 83 of the exit die 62. This move-ment may be somewhat similar to the movement of the annular or toroidal support 120 as described in UuS. Patent No. 4,393,809.
The throat portion 82 of the entrance die 61 prevents the flowable material within the die chamber 99 from leaking from die 18 through die 61~ Depending upon the flow properties of the coating material, throat portion 82 will have a diameter of about 3 mil to about 15 mil larger than the diameter of fila-ment 24.
The throat portion 93 of the exit die 62 regulates the thickness of the coat of coating material left on the fila-ment or conductor 24 exiting the coating die 18.
The size of the throat portion 93 of the exit die 62 varies in accordance with the size of the filament or conductor 24, and the desired thic]sness of the coat of coating material to be applied thereon. The method of the invention has been successfully used with filaments ranging from about 30 AW gauge to about 3/8" rod. Conductors of rectangular cross-sections and of other cross-sections can also be coated by the method and apparatus of the invention so that as long as the throat por-tions 82 and 93 of the entrance die 61 and exit die 62, respec-tively, can be provided in a geometrically similar shape. Coat-ings from about 1/2 mil to about 16 mils thick can be applied by the method of the invention. Depending upon the Elow proper-ties of the coating material, the throat portion 93 of the exit die 5~C~
62 will have a diameter in most cases from about the desired diameter to about 2 mils larger than the desired diameter of the coated filament or conductor 24 of magnet wire.
The coated filament or conductor 24 is then passed through the hardener 20 in order to harden the coating material thereon. While the structure of the hardener 20 and the function thereof has been described hereinabove, it should be emphasized here that the operation of the hardener 20 depends greatly upon the coating material used. Either a water quench or an air quench may be utilized. Additionally, in those flowable materials in which small amounts of solvent are used to aid in the properties of the flowable material, the hardener 20 may take the form of a filament heater 14, or a conventional curing oven (not shown). In all cases, the type of hardener 20 utilized and the temperature of the cooling liquid, air or other fluid utilized will depend both on the coating material and the speed at which the coated-filament passes through the hardener 20.
The operation and function of the take-up device 22 was described hereinabove. However, the speed at which the take-up device 22 was driven was not mentioned. The driver 114 is not limited in any way by the method of the invention. The speed at which the driver 114 drives the spool 32 of the take-up device 22, in the embodiment illustrated in Fig. 1 utilizing both pay-out 12 and take-up 22 devices, is solely limited by the pay-out 12 and take-up 22 devices themselves when applying any of the coating materials mentioned herein. When the pay-out device 12 is eliminated and conventional rolling and drawing operations are substituted therefore, the speed at which the take-up device 2Z is driven by the So driver 114 is solely limited by the take-up device 22, itself.
Specific examples in which conductors of various sizes have been coated with coating material such as above mentioned in accordance with the method of this invention are tabulated in Table 1. Table 1 solely relates to the production of magnet wire. Table 1 tabulates all of the essential properties of the coating material and the conductor, all of the essential process conditions, and all of the essential physical and electrical properties of the magnet wire produced in this specific example in accordance with the method of the invention utilizing the apparatus described hereinabove.
The magnet wire produced by the apparatus of the invention in accordance with-the-method of the invention meets all of the requirements of magnet wire made by other existing commercial processes. Table 1 tabulates the physical and electrical properties of various magnet wires manufactured in accordance with the method of the invention utilizing the apparatus of the invention. A
surprising characteristic of all magnet wires made in accordance with the method of the in-~ention utilizing the apparatus of the invention is the concentricity of the coating applied to the conductor and the continuity thereof. Both the concentricity and continuity are a surprising result when compared to magnet wires made by other existing commercial processes without regard to the means by which the conductor or filament 24 is centered within the coating die 18. Magnet wire produced by other commercial processes, such as the 57~
application of coatings from solution, periodically result in non-concentric coatings and non-continuous coatings. In fac-t, the continuity of coatings applied from solution is such that reliance upon a single coating of magnet wire insulation is unheard of; and for this reason and others, multiple coatings are used as above-mentioned.
Magnet wire having a single coat is a commercial reality due to the concentricity and thickness of the coatings that can be applied by the apparatus and method of the invention.
The invention provides an improved method and appara-tus for applying coatings of a flowable material concentrically to a moving elongated filament. In the manufacture of magnet wire, the method and apparatus of the invention is an improve-ment over conventional methods of manufacturing magnet wire.
By the invention, insulation can be applied to a continuously moving elongated conductor, concen-trically, to a desired thick-ness in a single pass. Materials can be applied by the inven-tion which can not be applied by the method and apparatus dis-closed in U.S. Patent No. 4,393,809 above mentioned. The speed is limited only by the pay-off and take-up devices. The con-ductor can be drawn or otherwise formed, coated, and spooled in a continuous operation which completely eliminates or substanti-ally reduces the use of solvents, thereby eliminating the cost of solvents and the need for pollution control equipment. The apparatus of the invention completely eliminates the need for highly complex machinery or dies which experience high wear and must be replaced periodically. The improved method and appara-tus of the invention has all of the advantages of
BACKGROUND OF THE INVENTION
The invention relates to magnet wire and a method and apparatus for manufacturing magnet wire, and more particularly, to a method and apparatus for applying a coating of flowable resin material on a continuously moving filament to a desired thickness in a single pass.
Magnet wire has been conventionally manufactured by passing a bare copper or aluminum conductor or a previously insulated copper or aluminum conductor through a bath of liquid enamel (a solution of resin material in a solvent thereof) and through an oven for driving off the solvent from the enamel and/or curing the resin, leaving a resin coat on the conductor.
The application of a coat of materîal to a filament from solution accounts for all of the magnet wire manufactured today. While some materials using today's technology can only be applied from solution, the cost ox the solvent expended in applying resin materials from solution is usually significant. The machinery used in this process is also higly complex and expensive, although the machinery cost is usually not a factor since most of such machinery has been in use for a considerable number of years. Still the original cost of such machinery is significant for new installations In addition to the cost of machinery and the solvent expended by such a process, there is the cost of providing and maintaining pollution control equipment;
since recently both Federal and State laws have required that the oven stack gases of such machines be essentially stripped of solvent beEore exhausting the gases to the atmosphere While various methods of 7~
burning the vaporized solvent and/or reclaiming the solvent have been proposed, all such methods result in further expense to the manufacturer.
Additionally, the application of a layer of material to a filament from solution usually requires several successive coats in order to result in a concentric coat of a desired thickness. For example, six coats may be required for a 3 mil coating, although in specific applications as many as 24 coats have been required. Also, multiple coats of certain materials cannot be applied successfully from solution due to a lack of good adhesion and wetting between coats.
It therefore has been desirable for some time to provide an improved method of manufacturing magnet wire which eliminates the use of solvent. Also, it would be additionally highly desirble to provide an improved method of manufacturing magnet wire which would utilize an apparatus of simple design. Also, it would be highly desirable to provide a method of manufacturing magnet wire which would allow the wire to be drawn coated and spooled in a continuous operation; conventionally the wire is drawn, annealed if necessary, spooled; and then coated and spooled again for shipment. Additionally, it would be highly desirable to provide a method and apparatus which can successfully apply multiple layer of materials which have heretofore not been possible.
Finally, it would be highly aesirable to provide an improved method and apparatus for manufacturing magnet wire which would not require the use of solvent or pollution control apparatus, or be limited to materials requiring an oven cure, or require multiple coats to obtain a coating of the required continuity and concentricity.
Applying coatings of resinous material by extrusion is substantially less common than applying coatings from solution, since conventional extrusion processes are extremely limited. Coatings of 4 mils and less are either extremely difficult to apply or impossible to apply by conventional extrusion processes. Also, the number of materials which are successfully applied by conventional extrusion processes are extremely limited.
Polyvinyl chloride, polyethylene, polypropylene and various elastomeric rubbers comprise 99% of the materials applied by extrusion. These materials are not used in a true magnet wire application, ire. an electrical winding, the turns of which are insulated to provide low voltage, mechanical and thermal protection between turns, and do not possess magnet wire properties. In contrast, these materials are conventionally used in lead wire or hook-up wire applications which must protect against the full imput line voltage of an electrical device. Conventionally, extrusion is used in the production of only cables, building wire, and lead or hook-up wire.
While the apparatus used in conventional extrusion processes is relatively simple when compared to a conventional wire coating tower, and the extrusion process can be carried out continuously whereby the filament may be drawn, coated and spooled in a continuous operatlon, still, a conventional extrusion apparatus is not without problems. Conventional extruders include a centering die, a material reservoir and a sizing die. The centering die mechanically centers the filament in the sizing die, the sizing die determines the exterior dimensions of the coated filament and the thickness of the coat applied to the filament. The primary problem associated with extrusion apparatus is the wear on the centering die. Since the centering die used to center the filament within the sizing die, the centering die must be finely adjusted to achieve a concentric coating and must be replaced periodically due to the wear resulting from the contact between the filament and the die. Centering dies tend to be expensive even when made of hardened steel, but because of the wear that occurs, diamond centering dies have been considered, but not widely used.
Therefore -it would be highly desirable to provide an improved method and apparatus for manufacturing magnet wire which would have all of the benefits of an extrusion process but none of the disadvantages. Such a method and apparatus would lower the cost of the machinery to manufacture magnet wixe and would eliminate the need for solvent, lower manufacturing costs, conserve raw materials and energy, eliminate the need for pollution control apparatus, require less expensive and simpler machinery than now is conventional, and allow for continuous operation from wire drawing to final shipment without being limited to materials from solution or oven cures.
SUMMARY OF THE INVENTION
It is therefore a primary object of this invention to provide an improved method and apparatus for manufacturing magnet wire.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire which does not require solutions of insulation material and thereore eliminates the need for solvents pollution control equipment or for 5~7~
reclaiming solvents from the manufacturing process, lowers the cost of manufacturing at least proportionally to the cost ox solvent, and conserves energy at least to the degree what energy is required to remove solvents from the insulation material.
It is also another object of this invention to provide an improved method and apparatus for manufacturing magnet wire which is not limited to the use ox insulation material solutions or materials requiring curing after application.
It is another object of this invention to provide a method and apparatus for manufacturing magnet wire which does not require multiple coats to obtain the required concentricity and/or continuity.
It is another object of this invention to provide an improved method and apparatus for manufacturlng magnet wlre in which a coating materîal Jan be applied to a continuously moving elongated filament to a desired thickness in a single pass.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire my which magnet wire can be manufactured at speeds which are limited only by filament pay-off and take-up devices It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire by which a coat of resin material may be applied to an elongated continuously moving filament to a desired single thickness in a single pass whereby the filament may be drawn or otherwise formed/ coated and spooled in a continuous operation.
It is another object of this invention to provide an improved method and apparatus for manuacturing S'~ [3 magnet wire which completely eliminates or substantially reduces the use of solvents thereby eliminating the cost of solvents and the need for pollution control equipment or to reclaim the solvents from the manufacturing proces 5 .
It is another object of this invention to provide an improved method and apparatus for rnanufactur.ing magnet wire which completely eliminates the need of highly complex machinery or dies which experience high wear and must be replaced periodically.
It is another object of this invention to provide an improved method and apparatus of manufacturing magnet wire which has all of the advantages of a conventional extrusion process but i5 not limited in the thinness of the coating applied to the filament by such a process.
It is another object of this invention to provide an improved method and apparatus for manufacturing magnet wire having all of the advantages of a conventional extrusion process but none of the disadvantages.
In the broader aspects of the invention, there is provided a novel method an apparatus for manufacturing magnet wire in a continuous process by which coatings of a flowable resin material may be applied concentrically to a moving elongated fil ment in thicknesses of about 16 mils or less. The filament can be a bare copper or aluminum conductor having round or rectangular configuration ox an insulated conductor upon which a top or an intermediate coat of material is desirably applied Coatings of one-half mil and one mil also can be applied by the method of the invention D By the method and apparatus of he i.nvention, magnet wire can be manufactllred by continuously drawin9 the wire to 7~
size, annealing -the wire, if necessary, insulating the wire wi-th one or more coa-ts of flowable resin material, curing the resin material, if necessary, hardening the resin ma-terial, and spooling the wire for shipment, wi-thout interruption a-t speeds limited only by -the filament pay-off and -take-up devices used. The apparatus oE the invention utilizes the flowable resin material to center the filamen-t in a die, -the size of the die controls the thickness of the coat to be applied. In the apparatus of the invention, only the resin material beiny applied to the filament is in contact with the filament. Thus, the mechanical wear normally associated with centering dies used in extrusion processes and like devices is completely eliminated. Further, -the apparatus and method of -the invention can be used to apply coats several times thinner than is possible with conventional extrusion apparatus and of materials different than those conventionally extruded onto filaments.
In specific embodiments using heat softenable materials or melts, curing is no longer required; and -thus, the need for curing, ca-taly-tic burners and the like as well as all concerns regarding atmospheric pollution are eliminated The coa-ted filaments and magnet wire made by the apparatus and in accord-ance with the method of the inven-tion have coatings which are surprisingly conce~ricand continuous when compared to magnet wire made by conventional methods and apparatus In accordance wi-th the present invention, there is provided a method of manufacturing magnet wire in which a flowable bu-t hardenable matexial is applied to an elongated conductor to a desired thickness in a single pass whereby said conduc-tor may be drawn or otherwise formed, coated and spooled in a continuous operation comprising the s-teps of:
a. passing said conduc-tor -through a stationary entrance die at a speed in excess of 100 fee-t per minute, , 7~3 b- passing said conduetor through a stationary exit die at a speed in excess of 100 feet per minute, said exit die having a throat portion, an entrance opening larger than said throat portion intereonneeted by a eonverging interior wall -thereby defining a die eavity between said throat portion and said opening and said conduc-tor and said wall, said entrance die and exit die defining and partially enclosing a die chamber therebetween, said eonductor in said dies being spaced from said dies, e. filling said die chamber with a flowable material including less than about 5% weight solvent at a temperature above the melting point thereof, d. raising the pressure of said material within said die ehamber above atmospheric pressure, e. passing said eonduetor through said die chamber thereby applying said flowable material onto said conductor, f. centering said conductor in said throat portion of said exit die solely with said material in said die chamber, g. wiping the exeess of said material from said eonduetor leaving an essentially eoneentric coat of said ma-terial on said conduetor of a thickness meeting the requirements of ANSI/NEMA Standards Publication No. MW1000-1977.
In accordance with another aspect of the invention, there is provided an apparatus for the manufacture of magnet wire eomprising a die apparatus, a filament pay-out deviee, a eoated filament take-up deviee, said die apparatus being loeated between said pay-out and take-up deviees, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion intereonnected by a converging interior wall - 9a --.,!,~. ', so and an exi-t opening larger than said -throat portion inter-connected by a diverging interior wall, said exi-t die haviny a throa-t portion, and an entrance opening larger than said throat portion in-terconnected by a converging interior wall, said die block having an interior passage communicating wi-th said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber between said diverging interior waLl and said passage and said converging interior wall, said entrance and exit dies being positioned to receive a filamen-t trained between said pay-out and take-up devices in said openings and tnroat portions thereof; a reservoir of flowable but hardenable material, means operatively connected to said reservoir for filling said central die chamber with said material and maintaining said material wi-thin said die chamber at elevated pressures, and means including said ma.terial in said die chamber for cen-tering said filament in said throat portion of said dies.
In accordance with another aspect of the invention, there is provided an apparatus for the manufact:ure of coated filaments such as magnet wire comprising a die apparatus, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging in-terior wall and an exit opening larger than said throa-t portion interconnected by a diverging interior wall, said exit die having a -throat portion, and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an in-terior passage communicating with said exi-t opening of said entrance die and said entrance opening of said exit die thereby defining a flowable material centering - 9b - . "
5~3 chamber between said diverging interior wall and said passage and said converging interior wall.
In accordance with another aspect of the invention, there is provided an apparatus for the manufacture of coated filaments such as magnet wire comprising: a bare filament pay-out device, a coated filament take-up device, and a die apparatus loca-ted between said pay-out and take-up devices, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion and an entrance opening and an exit opening larger than said throat portion, said throat portion connected to said entrance opening and interconnected by a diverging interior wall to said exit opening, said exit die having a throat portion and an exit opening and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage communicating wi-th said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber between said diverging interior wall and said passage and said converging interior wall, an applicator means, connected to a reservoir of coating material, for filling said die chamber with said coating material at a desired pressure, upon said filament entering said die apparatus said converging interior wall providing a surface adjacent to which said material creates a support of coating material such that the filament does not contact the die and the filament it centered in said die throats and forms a continuous and concentric layer of coating material on said filament.
BRIEF DESCRIPTION OF TIIE DRAWINGS
The above mentioned and other features and objects , . .
5~7~
of this invention and the manner of attaining them will become more apparent and the invention itself will be - 9d -5~
best ~lnderstood by reference to the following description of the invention taken in conjunction with the accompanying drawings wherein:
Fig. 1 is a perspective, fragmentary and diagramatic view of the apparatus of the invention;
Fig. 2 is a cross sectional view of the coating die of the invention, taken substantially along the Section Line 2-2 of Fiy. 1;
Fig. 3 is a front plan view of the coating die of the invention taken substantially along the Section Line 3-3 of Fig. 1; and Fig. 4 is a cross-sectional view of the coating die of the invention taken substantially along the Section Line 4-4 of Fig. 2.
DESCRIPTION OF A SPECIFIC EMBODIMENT
., . - _ APPARATUS
Referring to the drawings, and specifically Fig. 1, the apparatus of the invention will be descried. The apparatus 10 generally consists of a filament pay-out device 12, a filament heater 14, a coating material dispenser 16, a coating die 18l a hardener 20, and a filament take-up device 22. As shown in Fiy. 1, the filament 24 is broken at 26, at ~B, and at 30 . At the filament break 26, when the apparatus of the invention is used to manufacture magnet wire, conventional wire drawing apparatus may be insertedO Thus, an oversized filament 24 may be reduced to the desired size by the drawing equipment prior to coating the filament. The filament heater 14 in a specific embodiment in which magnet wire is being manufactured by the apparatus of the invention may include an annealer whereby the 4S7~
effects of drawing the wire or stretchlng the wire may be eliminated. In other specific embodiments in which magnet wire is being manufactured by the apparatus of the invention, additional coating dies 18 and hardeners 20 may be inserted at 28 such that successive coats of different coating materials may be applied to the filament in a continuous manner.
The term "filament" is used herein for all strand materials. Filaments thus include both copper and aluminum conductors and insulated copper and aluminum ronductors which prior to the application of a coat of material by the apparatus and method of the invention have been insulated with a base coat of insulating material, a tape of insulating material either spirally or longitudinally wrapped on the conductor, or other conventional insulating materials, and other strand materials desirably coated. While the specific embodiments herein descrlbed primarily relate to the manufacture of magnet wire, the apparatus of the invention is thought to-have-utility in coating all sorts of filaments other than conductors or insulated conductors in the production of magnet wire.
The term "10wable materiall' is used herein for the general class of coating materials applied by the method and apparatus of the invention Again, while the specific embodiments herein described refer to meltable coating materials which can be hardened by cooling the material to ambient temperatures, other coating materials which are flowable at elevated temperatures and pressures are contemplated as being within the general class of materials which can be applied by the method and apparatus of the invention. These materials include materials which are initially flowable but later 5~
hardened by curing or the~mosetting the material and also coating materials which may include up to about 5%
by weight ox solvent to render them flowable and later hardenable by driving the solvent from the material. In the manufacture of magnet wire, several different materials can be applied by the method and apparatus of the invention. These include but are not limited to polyamides such as Nylon, polyethylene terephthalates, polybutylene terephthalates, polyethylenes, polyphenylene sulfide, polycarbonate~, polypropylenes, polyethersulfone, polyether imides~ polyether etherketone, polysulphonesl epoxys, flurocarbons including ethylene-chlorotrifluoroethylene and hylene tetrafluoroethylene polyvinyl formal, phenoxys, polyvinyl butyrol, polyamide-imide, polyesters and combinations thereof.
The filament pay-out device 12 includes a spool 32 on which the filament 24 desirably coated is stored.
The spool 32 is mounted on spindle 34 of the pay-out device 12 so as to freely rotate in the direction of the arrow 36. Operatively associated with the spool 32 is a brake 3~ which restrains the rotation of the spool 32 as the filament 24 is being pulled therefrom by the taXe-up device 22 so as to prevent entanglements. In accordance with the method of the invention, it is highly possible that in a magnet wire manufacturing plant where conductors are being rolled, drawn or otherwise reduced in size to desirable conductor from ingots, the pay-out device 12 can be completely eliminated, since the remaining apparatus can be used to coat conductors continuously in a single pass as the conductor is supplied from such rolling and drawing apparatus The reels 32 in this instance can be the reels upon which bar copper and aluminum conductors are now transported from the rolling and drawing operations to the magnPt s~3 wire manufacturing plants. In all instances where the take-up device 12 is eliminated and rolling and drawing operations are substituted therefore, an annealer is an essential part of the apparatus in order to eliminate the effects of working the conductor during the rolling and drawing operations.
Filament heater 14 is an essential part of the apparatus of the invention to be used in the performance of the method of the invention. A filament heater may be used solely to raise the temperature of the filament prior to the application of the coating material or may be an annealer if hard bare wire is used or to further reduce the effects of the aforementioned rolling and drawing process, if required. Thus, in a specific embodiment, the filament heater 14 may consist of an annealer, or may consist ox a filament heater. In the specific filament heater embodiment 14 illustrated in Fig. 1, the filament heater comprises a resistance coil 40 being generally tubular in shape and having opposite open ends 42 and 44. The filament or conductor 24 is trained between the pay-out device 12 and the tàke-up device 22 through the coil 40. The filament heater 14 is also provided with a control 46 by which the temperature of the conductor 24 can be controlled. The filament heaver 14 may also include a filament temperature measuring device such as a radiation pyrometer. Hereinafter in specific examples, the approximate wire temperatures reported herein are measured by such a device.
The coating die 18 is illustratecl in Figs. 1 through 4. The coating die 18 includes an entrance die 61, an exit die 62 and a die block 64. entrance die 61 is mounted in the forward portion of die block 64 by 5~7(3 screws 66. Exit die 62 is mounted in the rearward portion of die block 64 by screws 66'. Separating entrance die 61 and exit die 62 is an interior passage 65. Die block 64 is provided with heater bores 68 in which heaters 70 are positioned. In a specific embodiment, etch heater 70 may be a tubular calrod heater. Additionally, the die block 69 is provided with a thermocouple bore 72 therein in which a thermocouple 74 (shown only in Fig. 4) may be positioned.
Furthermore, die block 64 is provided with a nozzle bore 75 therein to which the nozzle 54 of material applicator 16 is connected. Hereinafter die temperatures are reported with regard to specific examples; these die temperatures are measured by thermocouple 74~ Heaters 70 are connected by suitable conductors to a heater 76.
seater 76 i5 provided with paired controls 78 whereby the temperature of the entrance vie 61 and the exit die 62 each can be elevated above ambient temperature (for each die) and controlled, respectively, as desired.
eferring to Fig. 2, the entrance die 61 is shown in cross-section to include an entrance opening 80, a throat 82 and a converging interior wall 84 which interconnects the throat 82 and the entrance opening 80 of the entrance die 61. Entrance die 61 also has an exit opening 86 and a diverging interior wall 88 interconnecting the throat 82 and the exit opening 86.
In a specific embodiment, the entrance die 61 can he constructed as illustrated in a two-piece fashion hazing a central piece 90 including a throat portion of harder and more wear-resistant material, and exterior piece 90 which includes both the entrance opening 80 and the exit opening 864 The exit die 62 is also shown in Fross-section to include an entrance opening 92, a throat 93 and a converging interior wall 94 which interconnects the throat 93 and the entrance opening 92 of the exit die 62. Converging interior wall 94 partially defines a die chamber 9S as will be mentioned hereinafter. Exit die 62 also has an exit opening 96 and a diverging interior wall 97 that interconnects the throat 93 and the exit opening 96. In a specific embodiment, the exit die 62 can be constructed as illustrated in a two-piece fashion having a central piece 98 including a throat portion of harder and more wear resistant material than the exterior piece 98' which includes both the entrance opening 92 and exit opening 96.
In a specific embodiment, the converging wall 84 and 94 define an angle A with conductor 24 of about 5 to about 40 degrees and throats 82 and 93 are tapered from converging walls 84 and 94 to diverging wall 88 and 97 so as to define an angle with the conductor 24 of about .
1 to about 2 degrees.
The flo~able material applicator 16 has a chute 48 by which the material is supplied to the applicator, a material reservoir 50 in which the material may be stored, and a positive displacement pump 52 which pressurizes reservoir 50 and dispenses the flowable material through a nozzle 54. When using melts or other temperature responsive flowable materials, reservoir 50 is provided with a heater and a control device 56 by which the temperature of the material in the reservoir can be controlled. An additional control device 58 is associated with the positive displacement pump 52 to control the amount of flowable material passing through nozzle 54. In a specific embodiment, the fluid material applicator 16 may be an extrusion apparatus having the features above described. In those applications in which the flowable material is rendered more flowable by the use of a small portion of solvent, both the coating material and the solvent may be fed into the applicator via the chute 48 and the reservoir 50 may be provided with a mixing apparatus having associated therewith a separate control 60.
The central die chamber 95 is completely defined by the diverging wall 88 of entrance die 61, the converging interior wall 94 of exit die 62, and the walls of interior passage 65 of die block 64. Die chamber 95 is positioned between throat 82 and throat 93. The nozzle 54 is connected to nozzle bore 75 so that coating material in reservoir 50 may be injected into the central die chamber 99 under pressure by material applicator 16. The filament or conductor 24 is trained between the pay-out device 12 and the take-up device 22 through the entranee die 61, the central die chamber 95, and the exit die 62~
The hardener 20 functions to harden the coat of material on the filament or conductor 24 prior to spooling the coated filament or magnet wire by the take-up device 22. the hardener 20 as illustrated includes a trough 100 having opposite open ends 102 and 104. The trough is positioned such that the filament or conductor 24 can be trained to enter the open end 102, pass through the trough 100j and exit the open end 104.
Also as shown, the trough 100 is sloped downwardly toward the open end 102 and provided with a source of cooling fluid, such as waxer 108~ adjacent open end 104 and a drain 110 adjacent open end 132. In many specific embodiments, a water quench uti.lizing tne structure of -the hard-ener 20 is desi:red. In other specific embodiments, a quench is not required and thus, the cooling flllid is no-t used. In these embodiments, ei-ther a flow of ambien-t air or rel-rigerated air (where available) is trained on the coa-ted conductor or filament 24.
In specific embodiments in which multip]e coats of dif-ferent materials are being applied to the filament or conductor 24 by successive spaced apart coating dies 18, the particular coating 10 die used depends on the material to be applied and maybe either the coating die 18 having an entrance die 61 and an exit die 62 as disclosed herein or the coating die disclosed in united States Patent No. 4,393,809. The particular coa-ting die used depends on the material to be applied. Each of the coating dies will have a material applicator 16 associated therewith and may have a hard-ener 20 associated therewith. The term "coating station" is used herein to refer to the assemblage of a material applicator 16, a coating die, and a hardener 20. In these embodiments, there will be a plurality of spaced apart coating stations between the pay-20 out device 12 and the take-up device 22.
The take-up device 22 in many respects is similar to the pay-out device 12. The take-up device 22 comprises a reel 32 on which the coated filament or conductor 24 is spooled for ship-men-t. Thus reels 32 may be the conventional spools on which coated filaments are conventionally shipped. Spools 32 are moun-t-ed for rotation on a spindle 34 so as to be driven in the direc-tion of the arrow 112. Operatively connected to the spool 32 is a spool driver 114 which drives the spool 32 and -thereby pulls the filament or conductor 24 from the spool or reel 32 of the pay-out device 12.
i - 17 -57C~
THE METHOD
The method of the invention will Dow be described.
Reference to Figs. 1 through 4 will be referred to and the terms "flowable materialn and "filament" will be used as above defined. This description of the method of the invention will also specifically refer to the manufacture of magnet wire in a single pass whereby the filament or conductor is drawn or otherwise formed, coated and spooled in a continuous operation.
A continuous supply of the filament or conductor 24 is provided either by the pay-out device 12 as illustrated in Fig. 1 or from a rolling and drawing operation. If supplied from a rolling and drawing operation, the conductor 24 is always annealed to remove all effects of the rolling and drawing operation.
The filament or conductor 24 is then heated, if desired. Whether or not the filament 24-is héated is dependant upon the coating material utilized and the wire properties desired Thus, the filament 24 may be heated by the heating device 14 to a temperature from about ambient temperature to about the decomposition temperature of the coating material. In most applications utilizing a melt or a heat-responsive flowable material in which the coat of material is desirably adhered to the filament or conductor 24, the filament or conductor is heated to a temperature from just below to about the melting point of the coating materialO In most applications utilizing a melt or a heat-responsive flowable material in which the adhesion of the coat of material to the filament or conductor 24 is not required, the filament or conductor 24 is maintained from about the ambient temperature to 51 i~htly abov2 the ambient temperature The central die chamber 99 is then filled with a flowable material. The flowable material is stored in the material reservoir 50 at a flowable temperature and pressure and is injected into the central die chamber 99 by applicator 16. Once the central die chamber 99 has been filled with material, the flowable material contained therein ~7ill assume the pressure of the flowable coating material in the reservoir 50. Pump 52 must have an adequate capacity to maintain pressures up to about 2000 psi in reservoir 50 and chamber 99. By control 58, the responsiveness to pressure changes desired can be controlled. By controls 56 and 78, the temperature of the material in the reservoir 50 and chamber 99 can be controlled. The pressurized temperature of the flowable material in the central die chamber 99 must be carefully controlled for several reasons. First, if the pressure and/or temperature of the flowable material in the central die chamber 99 is too great, the flowable coating material may have the tendency -to leak in significant quantities from the central die chamber 99 through throat 82, although the filament passing through throat 82 will allow operating pressures higher than that at which the flowable material Jill leak from opening 80 when the filament is stationary in opening 80. Any significant leakage of flowable coating ma.erial from the die block 64 is not preferred. Secondly, both the pressure and temperature of the flowable material relate to the viscosity and/or flow characteristics of the flowable material, and must be such that the viscosity and/or flow characteristics of the flowable material performs its centering function relative to the exit die 62 and produces a concentric coating as will be subsequently discussed, wets the filament to be coated, and suitably adheres to the filament. Thirdly, if the pressure and the temperature of the flowable material is too low, excessive filament stretching may occur from die 18 excessively resisting the movement of filament therethrough. It is for these reasons, that the applicator 1G is provided with controls 56, 58, and 60.
The coating material is then applied to the filament or conductor 24 by passing the same through die 1 a . The coating material within the die chamber functions to center the filament or conductor 24 within the throat portions 82 and 93 of dies 61 and 6~. In all instances known to the applicants wherein the central die chamber 99 is properly filled with coating material 115 and the temperature and pressure therein are properly controlled, filaments or conductors 24 that are coated by the method and apparatus of the invention have a surprlsingly concentric and continuous coat of coating material thereon. Conversely, in all situations in which the central die chamber 99 is not properly filled, anon the temperature and pressure therein is not properly controlled, a non-concentric and discontinuous coat of coating material is applied to the filament or conductor 24. Thus, the proper filling of the central die chamber 99 with coating material the control of the temperature and pressure of the coating material therein are essential to the method of the invention. Coating materials of various types have teen successfully applied in accordance with the method of the invention by the above~described apparatus at viscosities from about 5,000 cps to 200,000 cpsO
Applicant does not completely underskand the actions of the flowable material within the central die 3~
chamber 99 which results in filaments having coatings of perfec-t concentricity and continui-ty thereon. The coating material con-tained within the central die chamber 99 is believed to have movement adjacent the throat 83 of the exit die 62. This move-ment may be somewhat similar to the movement of the annular or toroidal support 120 as described in UuS. Patent No. 4,393,809.
The throat portion 82 of the entrance die 61 prevents the flowable material within the die chamber 99 from leaking from die 18 through die 61~ Depending upon the flow properties of the coating material, throat portion 82 will have a diameter of about 3 mil to about 15 mil larger than the diameter of fila-ment 24.
The throat portion 93 of the exit die 62 regulates the thickness of the coat of coating material left on the fila-ment or conductor 24 exiting the coating die 18.
The size of the throat portion 93 of the exit die 62 varies in accordance with the size of the filament or conductor 24, and the desired thic]sness of the coat of coating material to be applied thereon. The method of the invention has been successfully used with filaments ranging from about 30 AW gauge to about 3/8" rod. Conductors of rectangular cross-sections and of other cross-sections can also be coated by the method and apparatus of the invention so that as long as the throat por-tions 82 and 93 of the entrance die 61 and exit die 62, respec-tively, can be provided in a geometrically similar shape. Coat-ings from about 1/2 mil to about 16 mils thick can be applied by the method of the invention. Depending upon the Elow proper-ties of the coating material, the throat portion 93 of the exit die 5~C~
62 will have a diameter in most cases from about the desired diameter to about 2 mils larger than the desired diameter of the coated filament or conductor 24 of magnet wire.
The coated filament or conductor 24 is then passed through the hardener 20 in order to harden the coating material thereon. While the structure of the hardener 20 and the function thereof has been described hereinabove, it should be emphasized here that the operation of the hardener 20 depends greatly upon the coating material used. Either a water quench or an air quench may be utilized. Additionally, in those flowable materials in which small amounts of solvent are used to aid in the properties of the flowable material, the hardener 20 may take the form of a filament heater 14, or a conventional curing oven (not shown). In all cases, the type of hardener 20 utilized and the temperature of the cooling liquid, air or other fluid utilized will depend both on the coating material and the speed at which the coated-filament passes through the hardener 20.
The operation and function of the take-up device 22 was described hereinabove. However, the speed at which the take-up device 22 was driven was not mentioned. The driver 114 is not limited in any way by the method of the invention. The speed at which the driver 114 drives the spool 32 of the take-up device 22, in the embodiment illustrated in Fig. 1 utilizing both pay-out 12 and take-up 22 devices, is solely limited by the pay-out 12 and take-up 22 devices themselves when applying any of the coating materials mentioned herein. When the pay-out device 12 is eliminated and conventional rolling and drawing operations are substituted therefore, the speed at which the take-up device 2Z is driven by the So driver 114 is solely limited by the take-up device 22, itself.
Specific examples in which conductors of various sizes have been coated with coating material such as above mentioned in accordance with the method of this invention are tabulated in Table 1. Table 1 solely relates to the production of magnet wire. Table 1 tabulates all of the essential properties of the coating material and the conductor, all of the essential process conditions, and all of the essential physical and electrical properties of the magnet wire produced in this specific example in accordance with the method of the invention utilizing the apparatus described hereinabove.
The magnet wire produced by the apparatus of the invention in accordance with-the-method of the invention meets all of the requirements of magnet wire made by other existing commercial processes. Table 1 tabulates the physical and electrical properties of various magnet wires manufactured in accordance with the method of the invention utilizing the apparatus of the invention. A
surprising characteristic of all magnet wires made in accordance with the method of the in-~ention utilizing the apparatus of the invention is the concentricity of the coating applied to the conductor and the continuity thereof. Both the concentricity and continuity are a surprising result when compared to magnet wires made by other existing commercial processes without regard to the means by which the conductor or filament 24 is centered within the coating die 18. Magnet wire produced by other commercial processes, such as the 57~
application of coatings from solution, periodically result in non-concentric coatings and non-continuous coatings. In fac-t, the continuity of coatings applied from solution is such that reliance upon a single coating of magnet wire insulation is unheard of; and for this reason and others, multiple coatings are used as above-mentioned.
Magnet wire having a single coat is a commercial reality due to the concentricity and thickness of the coatings that can be applied by the apparatus and method of the invention.
The invention provides an improved method and appara-tus for applying coatings of a flowable material concentrically to a moving elongated filament. In the manufacture of magnet wire, the method and apparatus of the invention is an improve-ment over conventional methods of manufacturing magnet wire.
By the invention, insulation can be applied to a continuously moving elongated conductor, concen-trically, to a desired thick-ness in a single pass. Materials can be applied by the inven-tion which can not be applied by the method and apparatus dis-closed in U.S. Patent No. 4,393,809 above mentioned. The speed is limited only by the pay-off and take-up devices. The con-ductor can be drawn or otherwise formed, coated, and spooled in a continuous operation which completely eliminates or substanti-ally reduces the use of solvents, thereby eliminating the cost of solvents and the need for pollution control equipment. The apparatus of the invention completely eliminates the need for highly complex machinery or dies which experience high wear and must be replaced periodically. The improved method and appara-tus of the invention has all of the advantages of
2~
7~
a conventional extrusion process but none of the disadvantages While there have been described above the principles of this invention in connected with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.
457~ ' i "6 , o 2 -- o N æ
~3 D _ _ Jo c vl O l _ C7 _ 01 n ~i3 c L _ :~ -o ~5 U a L X Q C- af O r ED
7~
a conventional extrusion process but none of the disadvantages While there have been described above the principles of this invention in connected with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of the invention.
457~ ' i "6 , o 2 -- o N æ
~3 D _ _ Jo c vl O l _ C7 _ 01 n ~i3 c L _ :~ -o ~5 U a L X Q C- af O r ED
3 l Of Q LID ED a_ m !~ w _ or LU ~3 _ pa .
It L _ _ n _ O a o N CO N 8 N O N N N
à en N o l ~0 _ 3 I N ¦ 3 N N A Us a N N ¦ Y 2 51 N N o o a 0 9 o R
N N O N N O N O _ _ O s O N O N O
A N Ox' US ,~ go ., o d l o o b _ N O N 3 j o c o o o - I¦ A _ a 8 i - `
31 W ! QD ~3 lL O W 1- I'D tL , 'I ~3 U t- O C I_ 57~
8 _ o~o N _ N ~0 _ ~3 _ I; N N 8 8 L L OO O ~0 l l 8 n o _ o N O -- 8 . LU _ o_ us us _ N or o ~3 N O O l f do _ r L No JO N _ ED 8 l o v N S o -- 8 . 8 _ oN ,PD N _ oo N 8 N o O N 2 o _ o _ N O n NN O N n N ~3 N I; O N n 7 _ n _ _ n o _ N _ _ o N ~3 N O O N b S N o _ O N $ _ 0 N o o O _ O O o JO OS ox _ o ¦~ I` 1 8 lo¦O No 81 n I w 3 o _ o b n O O N O O l O N n O a n d 2 1 _ N n N N 8 o o o o N 2 N
; Z N N N N _ N `D n 8 N V N N n r- o w O N N b N _ N ED N ~3 N O O N o O O
Z N NO I:o _ N O _ _ N O O O N _ N N us ED it O gig I f us us us Og 00 ::~
w ox o o ! N o g O N N :~ o O
N :~ _ O o i ¦ 2 o p,~ o N 8 Jo o o _ ,~ D O I
n O O N I l -- N O n 3 N O O N ON v o N o O O 01 a O O O ;~ O I D N O
, Z O Jo f _ O X OX j N f c D :~ " _ l . _ t U 0 57'~
'l . _ _ O O 0~ q` N O O to} N I; . _ O O
w z~ a g O O #I O gr 11~ o o o l N O O O O O _ _ I} N O O O N æ N
_ _ o _ o o o b o _ ~3 N O O N _ _ 3 a O O O 3 _ o o o n I S C --I N o N l o 0 13 N o o N
X L _ O O Ln O O _ O N O _. N o on .~ C O S O 0 I_ N O 1 1 0 'I 5 C O E O
_ I _ A I_ ¦ C O 5 1 3 , 3 D D 5~ ! L , ¦ 2, ¦ _ '' o
It L _ _ n _ O a o N CO N 8 N O N N N
à en N o l ~0 _ 3 I N ¦ 3 N N A Us a N N ¦ Y 2 51 N N o o a 0 9 o R
N N O N N O N O _ _ O s O N O N O
A N Ox' US ,~ go ., o d l o o b _ N O N 3 j o c o o o - I¦ A _ a 8 i - `
31 W ! QD ~3 lL O W 1- I'D tL , 'I ~3 U t- O C I_ 57~
8 _ o~o N _ N ~0 _ ~3 _ I; N N 8 8 L L OO O ~0 l l 8 n o _ o N O -- 8 . LU _ o_ us us _ N or o ~3 N O O l f do _ r L No JO N _ ED 8 l o v N S o -- 8 . 8 _ oN ,PD N _ oo N 8 N o O N 2 o _ o _ N O n NN O N n N ~3 N I; O N n 7 _ n _ _ n o _ N _ _ o N ~3 N O O N b S N o _ O N $ _ 0 N o o O _ O O o JO OS ox _ o ¦~ I` 1 8 lo¦O No 81 n I w 3 o _ o b n O O N O O l O N n O a n d 2 1 _ N n N N 8 o o o o N 2 N
; Z N N N N _ N `D n 8 N V N N n r- o w O N N b N _ N ED N ~3 N O O N o O O
Z N NO I:o _ N O _ _ N O O O N _ N N us ED it O gig I f us us us Og 00 ::~
w ox o o ! N o g O N N :~ o O
N :~ _ O o i ¦ 2 o p,~ o N 8 Jo o o _ ,~ D O I
n O O N I l -- N O n 3 N O O N ON v o N o O O 01 a O O O ;~ O I D N O
, Z O Jo f _ O X OX j N f c D :~ " _ l . _ t U 0 57'~
'l . _ _ O O 0~ q` N O O to} N I; . _ O O
w z~ a g O O #I O gr 11~ o o o l N O O O O O _ _ I} N O O O N æ N
_ _ o _ o o o b o _ ~3 N O O N _ _ 3 a O O O 3 _ o o o n I S C --I N o N l o 0 13 N o o N
X L _ O O Ln O O _ O N O _. N o on .~ C O S O 0 I_ N O 1 1 0 'I 5 C O E O
_ I _ A I_ ¦ C O 5 1 3 , 3 D D 5~ ! L , ¦ 2, ¦ _ '' o
Claims (31)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of manufacturing magnet wire in which a flow able but hardenable material is applied to an elongated conductor to a desired thickness in a single pass whereby said conductor may be drawn or otherwise formed, coated and spooled in a con-tinuous operation comprising the steps of:
a. passing said conductor through a stationary entrance die at a speed in excess of 100 feet per minute, b. passing said conductor through a stationary exit die at a speed in excess of 100 feet per minute, said exit die having a throat portion, an entrance opening larger than said throat por-tion interconnected by a converging interior wall thereby defin-ing a die cavity between said throat portion and said opening and said conductor and said wall, said entrance die and exit die defining and partially enclosing a die chamber therebetween, said conductor in said dies being spaced from said dies, c. filling said die chamber with a flowable material in-cluding less than about 5% weight solvent at a temperature above the melting point thereof, d. raising the pressure of said material within said die chamber above atmospheric pressure, e. passing said conductor through said die chamber thereby applying said flowable material onto said conductor, f. centering said conductor in said throat portion of said exit die solely with said material in said die chamber, g. wiping the excess of said material from said conductor leaving an essentially concentric coat of said material on said conductor of a thickness meeting the requirements of ANSI/NEMA
Standards Publication No. MWl000-1977.
a. passing said conductor through a stationary entrance die at a speed in excess of 100 feet per minute, b. passing said conductor through a stationary exit die at a speed in excess of 100 feet per minute, said exit die having a throat portion, an entrance opening larger than said throat por-tion interconnected by a converging interior wall thereby defin-ing a die cavity between said throat portion and said opening and said conductor and said wall, said entrance die and exit die defining and partially enclosing a die chamber therebetween, said conductor in said dies being spaced from said dies, c. filling said die chamber with a flowable material in-cluding less than about 5% weight solvent at a temperature above the melting point thereof, d. raising the pressure of said material within said die chamber above atmospheric pressure, e. passing said conductor through said die chamber thereby applying said flowable material onto said conductor, f. centering said conductor in said throat portion of said exit die solely with said material in said die chamber, g. wiping the excess of said material from said conductor leaving an essentially concentric coat of said material on said conductor of a thickness meeting the requirements of ANSI/NEMA
Standards Publication No. MWl000-1977.
2. The method of Claim 1 wherein said entrance die and exit die are held in a die block, said die block and said entrance and exit dies defining said die chamber, and wherein said filling step comprises passing said material through a passage in said die block, said passage fluidly connecting said die chamber with a material reservoir.
3. The method of Claim 1 further comprising the step of hardening said material on said conductor after said conductor leaves said exit die.
4. The method of Claim 1 wherein said wiping step includes the step of passing said conductor through said exit die, said exit die having a size relationship with the size of said con-ductor controlling the thickness of the coating material on said conductor.
5. The method of Claim 1 wherein said entrance die is small enough to prevent leakage of said material from said die chamber while said conductor is passing therethrough at said mat-erial pressure and large enough to allow said leakage when said conductor is stationary in said entrance die at said material pressure.
6. The method of Claim 1 wherein said centering step in-cludes the step of controlling the viscosity of said material within said die chamber.
7. The method of Claim 1 wherein said centering step in-cludes the step of controlling the pressure of said material with-in said die chamber.
8. The method of Claim 1 wherein said flowable material is a heat softenable material, and said centering step includes the step of controlling the temperature of said dies.
9. The method of Claim 1 wherein said flowable material is a heat softenable material, and said centering step includes the step of controlling the temperature of said conductor.
10. The method of Claim 1 wherein said centering step in-cludes the step causing movement of said material within said die chamber.
11. The method of Claim 1 wherein said conductor is of a group consisting of bare copper and aluminum conductors, and insulated conductors having base insulation previously applied.
12. The method of Claim 1 wherein said material of the group consisting of Nylon, polyethylene terephthalates, poly-butylene terephthalates, polyethylenes, polyphenylene sulfide, polycarbonates, polypropylenes, polyethersulfone, polyether im-ides, polyether etherketone, polysulphones , epoxys, fluoro-carbons including ethylene-chlorotrifluoroethylene and ethylene tetrafluoroethylene, polyvinyl formal, phenoxys, polyvinyl butyrol, polyamide-imide, polyesters and combinations thereof.
13. The method of Claim 1 wherein said material in said die chamber has a viscosity from about 5,000 cps to about 200,000 cps.
14. The method of Claim 1 wherein said conductor is from about 30 AWG gauge to about 3/8" rod.
15. The method of Claim 3 wherein said hardened material is from about 1/2 mil to about 16 mils thick.
16. The method of Claim 1 wherein said entrance die open-ing is from about four mils larger in diameter than said con-ductor.
17. The method of Claim 7 wherein said material pressure is below about 2000 psi.
18. An apparatus for the manufacture of magnet wire com-prising a die apparatus, a filament pay-out device, a coated filament take-up device, said die apparatus being located between said pay-out and take-up devices, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging interior wall and an exit opening larger than said throat portion interconnected by a diverging interior wall, said exit die having a throat portion, and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage comm-unicating with said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber between said diverging interior wall and said passage and said converging interior wall, said entrance and exit dies being pos-itioned to receive a filament trained between said pay-out and take-up devices in said openings and throat portions thereof;
a reservoir of flowable but hardenable material, means operative-ly connected to said reservoir for filling said central die chamber with said material and maintaining said material within said die chamber at elevated pressures, and means including said material in said die chamber for centering said filament in said throat portion of said dies.
a reservoir of flowable but hardenable material, means operative-ly connected to said reservoir for filling said central die chamber with said material and maintaining said material within said die chamber at elevated pressures, and means including said material in said die chamber for centering said filament in said throat portion of said dies.
19. The apparatus of Claim 18 including means for heating said filament between said pay-out device and said die apparatus.
20. The apparatus of Claim 18 wherein said heating means heats said filament from about ambient temperature to about the decomposition temperature of said material at a position prior to said filament entering said die apparatus.
21. The apparatus of Claim 20 including means for heating said filament between said pay-out device and said die apparatus, and means for heating said die apparatus and said material in said reservoir and said die chamber.
22. The apparatus of Claim 21 further comprising means including said filament and die apparatus and reservoir heating means for controlling the viscosity of said material in said die chamber.
23. The apparatus of Claim 22 further comprising means for driving said take-up device, and means for breaking said pay-out device.
24. The apparatus of Claim 23 including means for harden-ing said material on said filament between said die apparatus and said take-up device.
25. The apparatus of Claim 19 wherein said filament is of a group consisting of bare copper and bare aluminum conductors, and said filament heating means includes means for annealing said filament.
26. The apparatus of Claim 18 including a second die apparatus located between said pay-out and take-up devices, said second die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion, an entrance opening larger than said throat portion interconnected by a converging interior wall and an exit opening larger than said throat portion interconnected by a diverging interior wall, said exit die having a throat por-tion and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage communicating with said exit opening of said entrance die and said entrance opening of said exit die thereby defining a die chamber between said diverging interior wall and said passage and said converging interior wall, said entrance and exit dies being positioned to receive a filament trained between said pay-out and take-up devices in said openings and throat portions thereof.
27. The apparatus of Claim 24 wherein said die apparatus, filling and maintaining means, and hardening means comprises a filament coating station, and wherein said apparatus includes a plurality of said coating stations in a spaced-apart relation-ship to each other and said take-up and pay-out devices.
28. The apparatus of Claim 25 further comprising means for drawing said conductor into a conductor of similar size, said drawing means being positioned between said pay-out device and said filament heating means.
29. The apparatus of Claim 18 wherein said filling and maintaining means pressurizes said material within said die chamber to pressures up to about 2000 psi.
30. An apparatus for the manufacture of coated filaments such as magnet wire comprising a die apparatus, said die appara tus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat protion, an entrance opening larger than said throat por-tion interconnected by a converging interior wall and an exit opening larger than said throat portion interconnected by a diverging interior wall, said exit die having a throat portion, and an entrance opening larger than said throat portion inter-connected by a converging interior wall, said die block having an interior passage communicating with said exit opening of said entrance die and said entrance opening of said exit die thereby defining a flowable material centering chamber between said diverging interior wall and said passage and said converging interior wall.
31. An apparatus for the manufacture of coated filaments such as magnet wire comprising:
a bare filament pay-out device, a coated filament take-up device, and a die apparatus located between said pay-out and take-up devices, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion and an entrance opening and an exit opening larger than said throat portion, said throat portion con-nected to said entrance opening and interconnected by a diverg-ing interior wall to said exit opening, said exit die having a throat portion and an exit opening and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage communicating with said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber bet-ween said diverging interior wall and said passage and said con-verging interior wall, an applicator means, connected to a reservoir of coating material, for filling said die chamber with said coating mater-ial at a desired pressure, upon said filament entering said die apparatus said converg-ing interior wall providing a surface adjacent to which said material creates a support of coating material such that the filament does not contact the die and the filament is centered in said die throats and forms a continuous and concentric layer of coating material on said filament.
a bare filament pay-out device, a coated filament take-up device, and a die apparatus located between said pay-out and take-up devices, said die apparatus including entrance and exit dies and a die block, said die block being between said dies, said entrance die having a throat portion and an entrance opening and an exit opening larger than said throat portion, said throat portion con-nected to said entrance opening and interconnected by a diverg-ing interior wall to said exit opening, said exit die having a throat portion and an exit opening and an entrance opening larger than said throat portion interconnected by a converging interior wall, said die block having an interior passage communicating with said exit opening of said entrance die and said entrance opening of said exit die, thereby defining a die chamber bet-ween said diverging interior wall and said passage and said con-verging interior wall, an applicator means, connected to a reservoir of coating material, for filling said die chamber with said coating mater-ial at a desired pressure, upon said filament entering said die apparatus said converg-ing interior wall providing a surface adjacent to which said material creates a support of coating material such that the filament does not contact the die and the filament is centered in said die throats and forms a continuous and concentric layer of coating material on said filament.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000435917A CA1204570A (en) | 1983-09-01 | 1983-09-01 | Method and apparatus for manufacturing magnet wire |
| CA000496799A CA1219420A (en) | 1983-09-01 | 1985-12-03 | Method and apparatus for manufacturing magnet wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000435917A CA1204570A (en) | 1983-09-01 | 1983-09-01 | Method and apparatus for manufacturing magnet wire |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000496799A Division CA1219420A (en) | 1983-09-01 | 1985-12-03 | Method and apparatus for manufacturing magnet wire |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1204570A true CA1204570A (en) | 1986-05-20 |
Family
ID=4125998
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000435917A Expired CA1204570A (en) | 1983-09-01 | 1983-09-01 | Method and apparatus for manufacturing magnet wire |
| CA000496799A Expired CA1219420A (en) | 1983-09-01 | 1985-12-03 | Method and apparatus for manufacturing magnet wire |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000496799A Expired CA1219420A (en) | 1983-09-01 | 1985-12-03 | Method and apparatus for manufacturing magnet wire |
Country Status (1)
| Country | Link |
|---|---|
| CA (2) | CA1204570A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7973122B2 (en) | 2004-06-17 | 2011-07-05 | General Cable Technologies Corporation | Polyamideimide compositions having multifunctional core structures |
-
1983
- 1983-09-01 CA CA000435917A patent/CA1204570A/en not_active Expired
-
1985
- 1985-12-03 CA CA000496799A patent/CA1219420A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CA1219420A (en) | 1987-03-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4826706A (en) | Method and apparatus for manufacturing magnet wire | |
| US4391848A (en) | Method for manufacturing magnet wire | |
| US2175099A (en) | Method and apparatus for producing coated rubber-insulated conductors | |
| US4394417A (en) | Magnet wire | |
| US5151147A (en) | Coated article production system | |
| US4529564A (en) | Manufacture of low density sintered polytetrafluoroethylene insulated cable | |
| US4600268A (en) | Cable for telecommunications purposes and a method of manufacturing the same | |
| US4826725A (en) | Manufacture of low density, sintered polytetrafluorethylene articles | |
| GB1573196A (en) | Method and apparatus for extruding polytetrafluoroethlene tubing | |
| US4393809A (en) | Apparatus for manufacturing magnet wire | |
| US4521173A (en) | Apparatus for manufacturing magnet wire | |
| US4497849A (en) | Process for polymer coating electrical conductors | |
| US3776794A (en) | Reinforced flexible hose and method of manufacturing same | |
| US4489130A (en) | Magnet wire | |
| CA1204570A (en) | Method and apparatus for manufacturing magnet wire | |
| US3219738A (en) | Method of making wire-reinforced hose | |
| EP0063963B1 (en) | Method and apparatus for coating filaments | |
| US2366944A (en) | Manufacture of insulated conductors or other coated bodies | |
| CA1216721A (en) | Manufacture of low density sintered polytetrafluoroethylene insulated cable | |
| EP0198620B1 (en) | Manufacture of low density, sintered polytetrafluoroethylene articles | |
| US3503120A (en) | Method of producing covered wire | |
| CA1089206A (en) | Process for manufacturing coaxial cable | |
| CA2449582C (en) | Capacitance controlling process | |
| JPH055652B2 (en) | ||
| JP2002523865A (en) | In particular, a method for insulating a superconductor comprising a high Tc superconducting material and uses of the method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |