US3013900A - Cast coating of individual cartons - Google Patents

Description

Dec, 19, 1961 M. YEZEK ET AL 3,013,900

CAST COATING 0F INDIVIDUAL CARTONS Filed April 16, 1959 BYJM 5". M1191! 1 4 m 8 43/1. C-M

ATTORNEYS Unit Statm Patent 3,013,900 CAST CQATING F INDIVIDUAL CARTONS Milton Yezek and Walter C. Utschig, Battle Creek, Mich, assiguors to General Foods Corporation, White Plains, N.Y., a corporation of Delaware Filed Apr. 16, 1959, Ser. No. 806,910 11 (flaims. (Cl. 117-64) .This invention relates to a method of, and apparatus for, continuously producing individual cartons or carton blanks having a smooth glossy coating thereon of a thermoplastic material such as wax.

The method makes it posible to produce high gloss cartons at high production speeds owing to the steps, as hereinafter described, of rapidly removing heat from the thermoplastic agent deposited on the carton blanks, the agent being applied from a molten bath of the same. The invention is particularly characterized by the fact that by waxing individual carton blanks, there can be avoided the scufilng of the waxed surfaces that occurs when a continuous web of paper is first waxed and then cut into individual blanks. Furthermore, waxed waste, whether resulting from scuifing or other causes is reduced by waxing the individual blanks rather than a continuous web. Waxed waste is essentially not salvageable, unlike unwaxed waste.

The method generally comprises producing individual cartons having a smooth glossy coating of thermoplastic agent by applying a coating of molten agent on one side of each of a series of successive individual carton blanks. Each blank having the agent thereon in a plastic state is successively moved into the nip of an impression roll and a cold casting roll so that the coated side of the blank comes into intimate contact with the casting roll. The latter has a smooth mirror-finished surface with which the blank side makes contact and to which it adheres, being immovably disposed relatively thereto. As the casting roll rotates, the blank is urged into said intimate contact by means of the impression roll, thereby to uniformly distribute the agent on the adhering blank side. The surface of the casting roll is maintained at a temperature substantially below the fusing point of the agent to rapidly cool the coating on the blank. Continuing rotation of the casting roll serves to move the blank into contact with at least one body of cold water, thereby to further cool the coating, the water making contact with the uncoated side of the blank. While still immovably disposed relative to the casting roll, the blank is cooled by said roll and the body of water for a time sufficient to insure solidification of the coating, after which the blank is peeled from the casting roll, and there is obtained a blank having a smooth glossy coating of thermoplastic agent on one side thereof.

The invention may be better understood by referring to the accompanying drawing wherein:

FIG. 1 diagrammatically illustrates one method of carrying out the invention;

FIG. 2 diagrammatically illustrates a modified method;

FIGS. 3 and 4 diagrammatically illustrate modified steps of the various methods; and

FIG. 5 diagrammatically illustrates still another modified method.

In FIG. 1 there is shown a blank being moved from a suitable source (not shown) onto a moving conveyor belt 11 which introduces it to an applicator zone 12 where it moves through a plurality of pairs of applicator rolls, as illustrated by the positions of the preceding blanks 13 and 14 of the series being treated. As will be understood, the blanks are represented by side edge views of the same. The applicator rolls comprise pairs of upper and lower rolls 15 and 16, 17 and 1 8, and 19 and 20, the lower rolls being partly immersed in a bath 21 of molten thermoplastic agent contained in the tank 22, the latter being suit- Patented Dec. 19, 1961 ably heated by means not shown. The blank 14 with the coating of agent on one side of the same in a plastic state is shown being moved in a generally downward direction.

and the blank is immovably disposed relatively thereto; The impression roll 24 urges each blank into intimate con.

tact with the surface of roll .23 to uniformly distribute the agent between the blank side and the casting roll surface.

The casting roll is internally cooled by circulating a brin through it by means not shown so as to maintain the surface of the roll at a temperature substantially below the fusing point of the thermoplastic agent. After the blank is attached to the casting roll surface, and as the roll rotates further, each adhering blank is moved downwardly into the path of a cooling stream or spray 25, preferably a stream, of cold water applied to the outer uncoated side thereof from suitable means such as the spout 26, after which the blanks are moved into the bath 27 of cold water in tank 28 to further cool the coating. llt may be noted that a bafile :29 helps to direct the stream 25 against blank '30 and to prevent water from striking the impression roll 24 or the adjacent surfaces of the roll 23.

Each blank is maintained in the cold water bath 27 for a time sufiicient to insure solidification of the coating, note blanks 31 and 32. It will be understod that through out the foregoing cooling steps the blanks are immovably disposed relative to the casting roll surface.

By means of the combination of the internally cooled casting roll 23, the cold waterfall Q5, and the cold water bath 27, heat is rapidly removed from the hot coating of agent applied to the carton blanks, making it possible to process them at a high production rate.

The blanks leave the cold water bath Z7 and pass upwardly into the nip of roll 23 and a soft rubber wringer roll 33, the latter removing excess water from the uncoated side thereof, after which each blank is peeled from roll 23 by means of the knife 34. As thepeeling step is completed, the peeled blank tends to fall over to one side, away from roll 23, and onto a moving conveyor belt 3 5, note blanks 36, 37, and 38, which carries them away.

The depth of immersion of the casting roll in the water bath is variable but in no case should the water touch the roll 36. It should be noted that the low disposition of the latter roll relatively to, say, the rotational axis of roll 28, enables the peeled cartons to fall onto the conveyor 35 at least partly by the aid of gravity.

In FIG. 2 a modified method is shown wherein no water streams or sprays are used. Rather, the water level in the bath is increased, that is, the casting roll is immersed to a greater depth to provide increased cooling. Otherwise, the method of FIG. 2 is the same as that illustrated in FIG. 1, with the same structures being indicated by the same reference numerals except that in FIG. 2 the letter a is added to each numeral. It may be noted, however, that in FIG. 1 the lower disposition of the roll 33 permits the conveyor 35 to be disposed nearer the water bath. The applicator is only partly shown at 12a and the conveyor 11 of FIG. 1 is omitted to prevent the showing from becoming congested.

In FIG. 3 a modification is shown comprising the use of an air jet 40 in place of the knife 34 or 34a for peeling each blank from the casting roll 23b. The air stream issuing from the jet not only serves to peel the blank but also helps to blow it over onto the removing conveyor. Fur

ther, the air stream can be used as a means of removing any water droplets from the casting surface.

In FIG. 4 another modification is shown comprising the use of both the knife 34c and the air jet 400 to peel the blank 36c from the roll 23c. The use of the knife and the air jet together on the apparatus of FIG. 1 represents a preferred modification. The knife is a simple mechanical device for effecting a clean separation of the cartons, and the air jet further aids the separation while providing the advantages noted above. It will be understood that the knife and air jet may be used together on FIG. 2 as well as FIG. 1.

In FIG. 5 a further modification is illustrated according to which the blanks are peeled from the casting roll 23d beneath the level of the water in tank 28d. As shown, a knife blade 41 is suitably disposed beneath the water level and acts to peel the blank 32d, which then falls onto the adjacent moving conveyor belt '42 which is also disposed beneath the water level. The blanks are removed from the bath by engagement between an upper conveyor 43 and the lower conveyor 42, and are fed to a pair of wringer rolls 44 and 45 disposed above the water level which remove excess water from each blank, note blanks 37d and 38d. As may be apparent, the modification of FIG. 5 provides an easier and more positive transfer of the peeled blanks to the conveyors. More particularly, since each blank is removed from the lower half of the casting roll, the momentum of the roll enables the blank to fall forward towards the conveyor belt 42 and thus gives it a better start, so to speak. Also, the belt 42, by virtue of its disposition at or below the peeling point of the blank, further aids the blank in getting started on its way to a delivery Zone beyond rolls 44 and 45. If desired, an air jet such as 40 or 400 may be used in conjunction with the roll 23d to remove any water from the casting surface.

In FIG. 5 the applicator is only partly shown at 12d and the conveyor 11 of FIG. 1 is omitted, as in the case of FIG. 2, for the reason noted.

Looking at the invention in more detail, the packaging material of which the blanks are made may comprise printed or unprinted paper board, or a glue laminated structure comprising paper adhered to board by means of glue, or any other suitable material which would be benefitted by the presence of a highly glossy coating. It may be noted that in the case of a structure employing glue to secure the plies, if it were required to remove the coating agent from the closure flaps of the resulting carton blank in order to apply the glue, this could be done by a conventional steaming operation; whereas if one were dealing with a continuous wax type agent-coated laminated Web from which the individual blanks were to be cut, the steaming of such web might delaminate it.

Suitable papers, comprising in most cases a paper capable of being printed, are those in the range of 8 to 90 lbs. (basis 24 x 36500=2000 sq. ft.), such as papers made from chemical pulps including sulphate papers, sulphite papers, sulphate-sulphite combination papers, and soda pulp papers, these various papers being either uncoated or coated on one or both sides with a coating comprising clay, titanium dioxide, and binder; also papers made from chemical pulp or chemical pulp and groundwood combinations, coated or uncoated, which have been calendered or supercalendered, and including such papers as publishing papers, glassine, supercalendered sulphite papers, machine finish sulphite-sulphate papers, and machine finish and machine glazed sulphite-sulphate papers. Other materials are cellulosic films including cellophane and cellulose acetate; also foil of aluminum or tin.

By the term paper web it is intended to include webs of paper of the types noted, plastic films, metal foil, paperboard, and the like.

The paperboard may include boards made from pure chemical pulps such as bleached and unbleached kr-aft; soda and sulphite boards; boards made from semi-chemical pulp such as corrugating medium board and bleached semi-chemical board; boards made from waste materials such as chip board and jute board; and boards made from combinations of waste, groundwood and chemical pulps such as White patent coated news board, double Manila lined news, groundwood center, and double bleached lined waste-groundwood center board. Such board is normally specified in weight per 1000 sq. ft. and in points thickness (one point=0.00l inch); and on this basis any of the above types of board in the range of 20 to 160 lbs. per 1000 sq. ft. and 5 to 40 points may be suitable for use.

The thermoplastic agent may be an agent such as paratfin wax, microcrystalline wax, polyethylene of low molecular weight, say in the range of about 2000 to 21,000, etc. Also, other thermoplastic resins besides polyethylene are suitable, such as polypropylene of low molecular weight. Mixtures of two or more of the foregoing agents are suitable, such as a combination of parafiin wax and microcrystalline wax or polyethylene. The agent should, of course, be capable of producing gloss when deposited on the blank, and its melting point should not be so high as to injure the blank. In general, the particular composition to be used will depend on the particular product desired; for example, for a product having high gloss, moderate resistance to water vapor transfer (WVT), and good scutf-proofness, a suitable agent is polyethylene having a molecular weight of 6000 to 14,000; for high gloss, good WVT protection, and good scufi-proofness, a suitable agent is parafiin wax, or combinations of paraffin wax, microcrystalline wax and polyethylene.

The amount of thermoplastic agent is usually sufiicient to coat each blank to a thickness of about 0.0001 to 0.025 inch. For example, in the case of a composition comprising 50 parts by weight of paraffin (M.P. -145 F.) and 50 parts by weight of microcrystalline wax (M.P. -l47 F.) the agent may be applied in an amount ranging from 3 to 300 lbs. per 3000 sq. ft. of blank area.

The cold casting roll 23 is cooled by means of a brine which circulates within it, the circulating equipment being conventional and therefore not shown. The temperature of the cooled roll will depend on the thermoplastic coating agent, but in any event is below the fusing point of the thermoplastic agent. More particularly, the temperature may range from just above 32 F. to about 70 F. The lower temperature of such range should be such as to avoid the formation of ice on the casting roll surface. Preferably, the upper temperature is 40 F. Cooling of the coating on the blanks is quite rapid after initial contact with the cold roll. Such cooling step, which may be described as shock cooling, owing to its rapidity, is described in detail in co-pending application, Serial No. 663,269, filed June 3, 1957, now Patent No. 2,912,- 347, of which the present application is a continuation-inpart.

The cold roll 23 on which is provided the smooth surface necessary to produce the high gloss, preferably has a coating on such surface comprising a continuous, hard, glossy, and extremely smooth sheet of material such as vinyl acetate. This sheet or coating possesses good release properties, that is, readily permits the coated blank to be peeled off therefrom; or, stated another Way, the coating on the blank has good adherence to the casting roll but the cohesive strength of such coating for itself and to the blank exceeds the adherence of such coating for the casting roll. The sheet or coating on the casting roll has such a high degree of smoothness as to insure production of a continuous surface on the film or coating which is cast onto the blank. Instead of vinyl acetate, other compositions capable of offering a smooth, mirror-finished surface and good release properties may be employed, such as a sheet of copper or aluminum foil, or a lacquer of silicone or other resin. If desired, roll 23 may also comprise a polished metal roll, or a nickelor chromium-plated roll. In general, the casting surface of the cold roll should have a mirror-like finish and should have a surface which, when cooled to substantially below the fusion point of the coating on the paper blank, adheres to the latter coating with only a slight bond such that the coated blank can be readily peeled therefrom.

If desired, the cold roll 23' may be replaced by an endless belt having a smooth mirror-finished surface, although a roll is preferred.

The impression roll 24 is continuously heated, being maintained at an elevated temperature approximating the melting point of the thermoplastic agent during contact of the roll with the blank. As each blank passes through and out of the nip between rolls 23- and 24 of FIG. 1, for example, the heated roll 24 helps maintain the coating in a substantially plastic state, such state of plasticity being essential to enable roll 24, as it presses the coated agent against the smooth surface of roll 23, to smoothen the coating so that it becomes more uniformly continuous. Coincidently with the smoothening effect, the smooth mirror-finished surface of roll 23 imparts a high gloss to the coating.

Peeling off of the blank from roll 23 is controlled by the roll 33, which has a soft rubber Surface and which is in pressure contact with the blank-covered roll 23-. The rotational axis of roll 33 is substantially parallel to that of roll 23 to avoid any eccentricity in the peeling step and any distortion of the coating.

The water in bath 2.7 may be ordinary cold water having a temperature of about 32 to 60 F., although a colder brine solution may also be employed. The waterfall may be water of a temperature in the range of that of the water bath; it may also comprise brine.

It wil lbe understood that the foregoing disclosure relative to rolls 23, 2A, and 33, and bath 27, of FIG. 1, also apply to the corresponding structures of FIGS. 2 to 5.

The method may be operated at speeds of 200 to 500 ft. per minute, depending on the size and temperature of the casting roll, the amount of cooling water used, and the temperature of the water bath.

Besides the high production rates that are possible, there is a reduced loss of waxed waste, particularly as a results of eliminating the scufling incidental to the cutting of carton blanks from a continuous length of waxed web.

In any of the methods described, multiple streams of carton blanks may be processed. Thus, referring for example to FIG. 1, a plurality of wax applicators may be disposed side by side, that is, parallel to one another, and they may feed coated blanks in parallel streams to the cold casting roll, it being understood that such roll, and the impression roll 24, will be wide enough to accommodate two, three or more parallel streams of blanks. These blanks may then be cooled as described, removed from the casting roll by means of a plurality of knives or air jets and one or more cooperating wringer rolls, and fed either to one suitably wide conveyor belt or toa plurality of narrower belts.

Each coated blank has an extremely glossy, smooth, and continuous surface that is entirely free of imperfections such as crows fee. The continuity of each coat means that the resulting carton will have good resistance to the transfer of water vapor therethrough in the, subsequent use to which such carton may be put. The coating also protects the carton against scuffing, particularly in the case of inked papers where it prevents the ink from being transferred over onto non-inked areas as by pressure from a users fingers. In addition, the coating improves the product in respect of its sealing capacity toward air, etc.

It is to be understood that the invention is not restricted to the specific details of the foregoing description but is capable of obvious variations thereof without departing from its scope.

In the light of the foregoing description, the following is claimed.

We claim:

1. Method of continuously producing individual carton blanks having a smooth glossy coating thereon which 6 comprises continuously moving a series of longitudinally spaced individual carton blanks between spaced pairs of applicator rolls to deposit on one side of eachblank a coating of molten thermoplastic agent which fuses on chilling, then moving each said blank having the agent thereon in a plastic state in a generally downward di rection into the nip of a rubber impression roll and a cold casting roll to bring the coated side of the blank into intimate contact with the surface of the casting'roll, said casting roll having a smooth mirror-finished surface and said blank adhering thereto, said blank also being immovably disposed relatively to said surface, rotating said casting roll and urging succeeding portions of said blank into said intimate contact by means of said impression roll to uniformly distribute the agent on said blank side; maintaining the surface of the casting roll at a temperature substantially below the fusing point of said agent to cool the coating on said blank; rotating the casting roll to move said blank downwardly toward a body of cold water, coincidently with said downward, movement applying cold water to the outer uncoated side of said blank after pass-age of the same beyond said impression roll, thereby to further cool said coating; rotating said casting roll to move said blank through said body of cold water to cool said coating still further; maintaining each said blank, while immovably disposed relatively to and in contact with said casting roll, submerged in said body of water for a time sufiicient to insure solidification of said coating; then moving said blank upwardly from said body of water and passing the same into the nip of saidcasting roll and a soft rubber wringer roll to remove water from the uncoated side of the blank; peeling the cooled coated blank from the casting roll after the blank passes through said last mentioned nip, moving said peeled blank over onto a moving conveyor belt disposed adjacent said wringer roll, and recovering said blank having a smooth glossy coating of thermoplastic agent on one side thereof.

2. Method of continuously. producing individual carton blanks having a smooth glossy coating thereon which comprises continuously moving a series of longitudinally spaced individual carton blanks between spaced pairs of applicator rolls to deposit on one side of each blank a coating of molten thermoplastic agent which fuses on chilling, then moving each said blank having the agent thereon in a plastic state in a generally downward direction into the nip of a rubber impression roll and a cold casting roll to bring the coatedside of said blank into intimate adhering contact with the surface of the casting roll, said casting roll having a smooth mirrorfinished surface and said blank being immovably disposed relatively thereto, rotating said casting roll and urging succeeding portions of said blank into said intimate contact by means of said impression roll to uniformly distribute the agent on said blank side; maintaining the surface of the casting roll at a temperature substantially below the fusing point of said agent to cool the coating on said blank; rotating the casting roll to move said blank downwardly toward and through a body of cold water to further cool said coating; maintaining each said blank, while immovably disposed relatively to and in contact with said casting roll, submerged in said body of water for a time sufficient to insure solidification of said coating; peeling the cooled coated blank from the casting roll while said blank is still submerged in said body of water, moving said peeled blank through said water and onto a moving conveyor belt disposed in said water adjacent said casting roll, moving said peeled blank out of the water by means of said conveyor belt, passing the peeled blank through a pair of wringer rolls to remove excess water therefrom, and recovering said blank having a smooth glossy coating of thermoplastic agent on one side. thereof.

3. Method of continuously producing individual carton blanks having a smooth glossy coating thereon which comprises applying a coating of molten thermoplastic agent which fuses on chilling on one side of each of a series of individual carton blanks, moving each blank having the agent thereon in a plastic state into the nip of an impression roll and a cold casting roll so that the coated side of the blank comes into intimate contact with and adheres to the surface of the casting roll, said casting roll having a smooth mirror-finished surface and said blank being immovably disposed relatively thereto; rotating said casting roll and urging succeeding portions of the blank into said intimate contact by means of said impression roll, thereby to uniformly distribute the agent on said blank side; maintaining the surface of the casting roll at a temperature substantially below the fusing point of said agent to cool the coating on said blank; continuing to rotate the casting roll and moving the blank thereon toward and through a body of cold water which makes contact with the uncoated side of the blank, thereby to further cool said coating; maintaining said blank, while immovably disposed relatively to and in contact with said casting roll, submerged in said body of water for a time sufficient to insure solidification of said coating; peeling the cooled coated blank from the casting roll; and recovering said blank having a smooth glossy coating of thermoplastic agent on one side thereof.

4. Apparatus for producing smooth glossy coatings of thermoplastic agent on individual carton blanks compris ing applicator means for depositing a coating of melted thermoplastic agent on one side of each blank, a rotatable cold casting roll disposed beneath said applicator means for receiving each said blank on the surface of the same, said surface being smooth and having a mirror finish, said coated side of said blank making contact with and adhering to said surface, a rubber impression roll adjacent one side of said casting roll and forming a nip therewith, said adhering blank being adapted to pass through said nip whereby said impression roll acts to distribute the coating agent uniformly over said adhering side of the blank, each said blank thus becoming immovably disposed relatively to the casting roll surface, means for delivering cold water to the outer exposed side of said blank to cool the coating, baflie means to prevent water from wetting the impression roll and the casting roll surface intermediate the impression roll and the point of introduction of said blank on the casting roll, a cold water bath in which the lower part of said casting roll is immersed and in which said casting roll is adapted to rotate, said water bath making contact with said outer side of said adhering blank to cool the coating thereon, a rubber wringer roll disposed oppositely to said impression roll and forming a nip with the casting roll, said blank being adapted to pass through said last mentioned nip whereby the wringer roll removes excess water from the outer side thereof, means for peeling said adhering blank from the casting roll, and conveyor means adjacent said peeling means for receiving said peeled blank and removing the same.

5. Apparatus for producing smooth glossy coatings of thermoplastic agent on individual carton blanks comprising applicator means for depositing a coating of melted thermoplastic agent on one side of each blank, a rotatable cold casting roll for receiving each said blank on the surface of the same, said surface being smooth and having a mirror finish, said coated side of said blank making contact with and adhering to said surface, an impression roll forming a nip with said casting roll, each said adhering blank being adapted to pass through said nip whereby said impression roll acts to distribute the coating agent uniformly over said adhering side of said blank, each said blank thus becoming immovably disposed relatively to the casting roll surface, a cold water bath in which the lower part of said casting roll is immersed and in which said casting roll is adapted to rotate, said water making contact with the outer side of said adhering blank on the casting roll to cool the coating thereon, means for peeling said adhering blank from the casting roll, and

conveyor means adjacent said peeling means for receiving said peeled blank and removing the same.

6. Apparatus of claim 5 wherein said peeling means comprises a knife blade disposed beneath the surface of the water bath, said conveyor means being at least partly disposed beneath the surface of said water bath, and said disposition of the knife blade and conveyor means enabling each said carton blank to be peeled from the casting roll and transferred to the conveyor means while immersed in said water bath.

7. Apparatus for producing smooth glossy coatings of thermoplastic agent on paper comprising applicator means for depositing a coating of melted thermoplastic agent on one side of the paper, a rotatable cold casting roll for receiving the paper on the surface of the same, said surface being smooth and having a mirror finish, said coated side of the paper making contact with and adhering to said surface, an impression roll forming a nip with said casting roll, said paper being adapted to pass through said nip whereby said impression roll acts to distribute the coating agent uniformly over said adhering side of the paper, said paper thus becoming immovably disposed relatively to the casting roll surface, a cold water bath in which the lower part of said casting roll is immersed and in which said casting roll is adapted to rotate, said water making contact with the outer side of said adhering paper on the casting roll to cool the coating thereon, means for peeling the adhering paper from the casting roll, and means adjacent said peeling means for removing the paper.

8. Method of producing a smooth, glossy coating on an individual carton blank, which comprises applying to at least one side of said blank a coating of molten thermoplastic agent which fuses and solidifies on cooling, bringing said blank into contact with a cooled casting surface so that the coated side of said blank is disposed against and adheres to said casting surface, moving said casting surface to a position in which said blank adhered thereto is contacted by a liquid at a temperature substantially below the fusing point of said agent, and peeling the cooled coated blank from said casting surface.

9. Method of producing a smooth, glossy coating on an individual carton blank, which comprises applying to at least one side of said blank a coating of molten thermoplastic agent which fuses and solidifies on cooling, bringing said blank into contact with a cooled casting surface so that the coated side of said blank is disposed against and adheres to said casting surface, moving said casting surface to a position in which said blank adhered thereto is submerged in a body of liquid at a temperature substantially below the fusing point of said agent, maintaining said blank submerged in said body of liquid for a time sufficient to ensure solidification of said coating, and peeling the cooled coated blank from said casting surface.

10. Method of producing a smooth, glossy coating on an individual carton blank, which comprises applying to at least one side of said blank a coating of molten thermoplastic agent which fuses and solidifies on cooling, bringing said blank into contact with a cooled casting surface so that the coated side of said blank is disposed against and adheres to said casting surface, cascading a flow of liquid at a temperature substantially below the fusing point of said agent over a side of said blank opposed to said one coated side immediately after said blank has adhered to said casting surface, moving said casting surface to a position in which said blank adhered thereto is submerged in a body of liquid at a temperature substan tially below the fusing point of said agent, maintaining said blank submerged in said body of water for a time suflicient to ensure solidification of said coating, and peeling the cooled coated blank from said casting surface.

11. Method of producing a smooth, glossy coating on an individual carton blank, which comprises applying to at least one side of said blank a coating of molten thermoplastic agent which fuses and solidifies on cooling, bringing said blank into contact with a cooled casting surface so that the coated side of said blank is disposed against and adheres to said casting surface, moving said casting surface to a position in which said blank adhered thereto 5 is submerged in a body of liquid at a temperature substantially below the fusing point of said agent, maintaining said blank submerged in said body of liquid for a time sufiioient to ensure solidification of said coating, 'and While said blank is so submerged peeling the cooled coated 10 blank from said casting surface.

References Cited in the file of this patent UNITED STATES PATENTS Chester Nov. 23, Bradner July 2, Warner Oct. 24, Rumberger June 16, Curler et a1 June 30,

Claims (1)

1. METHOD OF CONTINUOUSLY PRODUCING INDIVIDUAL CARTON BLANKS HAVING A SMOOTH GLOSSY COATING THEREON WHICH COMPRISES CONTINUOUSLY MOVING A SERIES OF LONGITUDINALLY SPACED INDIVIDUAL CARTON BLANKS BETWEEN SPACED PAIRS OF APPLICATOR ROLLS TO DEPOSIT ON ONE SIDE OF EACH BLANK A COATING OF MOLTEN THERMOPLASTIC AGENT WHICH FUSES ON CHILLING, THEN MOVING EACH SAID BLANK HAVING THE AGENT THEREON IN A PLASTIC STATE IN A GENERALLY DOWNWARD DIRECTION INTO THE NIP OF A RUBBER IMPRESSION ROLL AND A COLD CASTING ROLL TO BRING THE COATED SIDE OF THE BLANK INTO INTIMATE CONTACT WITH THE SURFACE OF THE CASTING ROLL, SAID CASTING ROLL HAVING A SMOOTH MIRROR-FINISHED SURFACE AND SAID BLANK ADHERING THERETO, SAID BLANK ALSO BEING IMMOVABLY DISPOSED RELATIVELY TO SAID SURFACE, ROTATING SAID CASTING ROLL AND URGING SUCCEEDING PORTIONS OF SAID BLANK INTO SAID INTIMATE CONTACT BY MEANS OF SAID IMPRESSION ROLL TO UNIFORMLY DISTRIBUTE THE AGENT ON SAID BLANK SIDE, MAINTAINING THE SURFACE OF THE CASTING ROLL AT A TEMPERATURE SUBSTANTIALLY BELOW THE FUSING POINT OF SAID AGENT TO COOL THE COATING ON SAID BLANK, ROTATING THE CASTING ROLL TO MOVE SAID BLANK DOWNWARDLY TOWARD A BODY OF COLD WATER, COINCIDENTLY WITH SAID DOWNWARD MOVEMENT APPLYING COLD WATER TO THE OUTER UNCOATED SIDE OF SAID

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