US2173032A - Production of pile-surfaced materials - Google Patents

Description

p 12, 1939- H. A. WINTERMUTE 2,173,032

PRODUCTION OF PILE SURFACED MATERIALS Filed Nov. 23, 1933 3 Sheets-Sheet 1 Sept. 12, 1939. H A. WINTERMUTE 4 PRODUCTION OF PILE SURFACED MATERIALS I Filed Nov. 23, 1933 3 Sheets-Sheet 2 dbbozmw Sept. 12, 1939. H. A. WINTERMUTE 2,173,032

PRODUCTION OF FILE SURFACED MATERIALS Filed Nov. 23, 1953 a Sheets-Sheet s Patented Sept. 12, 1939 Harry A. Winter-mute, Plainfleld, N. 1., asizignor,

by mesne assignments, to Bohr-Manning Corporation, a corporation of Massachusetts Application November 23, 1933, Serial at. 699,456

/ 31 Claims.

This invention relates to the production of piled surfaces and pile surfaced materials and is particularly directed to apparatus and methods of operation adapted for the eflicient production 5 of such surfaces and surfaced materials by a process which involves positioning an adhesivecoated foundation material in an electric field and supplying pile-forming fibers thereto while in said field. l It has been found that the production of piled surfaces by electrically depositing fibers and the like by said process can be advantageously car ried out by means of the apparatus and methods of operating which are to be described herein- 15 after.

Among the novel features and objects of the present invention are included the use of a stream of air or other gas to disentangle the pile forming fibers and to carry them as individual 20 suspended particles into the electric field for deposition on the surface to be piled. Further objects of the invention are to use said stream of gas to prevent or break up the treeing of the fibers as they approach the surface to be 25 piled, to return for representation fibers that are not attached when first presented for deposition,

to supplement the force of gravity and the electrical forces available in moving the fibers towards the surface to be piled and to provide 30 methods of controlling the relative humidity and other gas conditions within the apparatus in which the pile formingoperations are carried on. Other objects comprise the use of auxiliary electrodes to provide eflicient, safe, and conveni- 3 ent control of the electrical forces and the use of special electrical circuits to prevent undesirable treeing and massing of the fibers and to provide advantageous conditions as will be herein after described. v 40 The method of pile construction to which the present invention applies comprises, broadly, establishing an electric .field of appreciable strength, for example, having a voltage drop of 45,000 volts between two relatively fiat, parallel, electrodes three inches apart; placing a base material, e. g. cloth or paper, coated with an adhesive, within the electric field (preferably parallel and adjacent to one boundary of saidfield) and 50 supplying pile-forming fibers to the region of the electric field. The fibers, initially carrying electric charges or becoming electrically charged by induction, move under the influence ofthe electric field and contact with the adhesive in 55 oriented position, i. e. perpendicular to the base,

whereby only one end of each fiber is attached to the base. i

The manner in which these and other objects of the invention are realized will be described in what follows, reference being had for the purpose of illustration to the accompanying drawings, in which:

Fig. 1 is a diagrammatic viewof a system comprising apparatus shown in sectional elevation and an electric circuit, which embodies certain principles of the invention;

Fig. 2 illustrates a system, shown more or less diagrammatically, but for the most part in sectional elevation, for practicing one embodiment of the invention;

Fig. 3 shows apparatus, in sectional elevation, for practicing the principles of the invention in somewhat different manner; and

Fig. 4 is a diagrammatical representation of a circuit which may be substituted in some cases for the circuit shown in Fig. 1.

Referring to Fig. 1-, numeral 5 designates a more or less air tight casing in which are supported two electrodes, I and 2, respectively, between which may be set up a strong electric field.. A source of energy, to be described later, is connected to electrode I by-electrical conductor 3 and to electrode 2 by conductor 4, the latter electrode, and casing 5 also, being preferably connected to ground as shown at 6. Electrode l-is insulated from casing 5 by insulating support I and tube 8. Tube 8 functions both as an insulating support and as an inlet bushing for conductor 3. Electrode 2, which is shown as a screen, is supported from the sides of easing 5 by imperforate plate-like members 9', 9. These are free from points or projecting edges, it being desirable that no corona discharge emanate from the apparatus while it is energized.

Above electrode 2 is a basket for sitting the 40 fibers to be used in making piled surfaces. It

comprises a screen l0; preferably of closer mesh than that of electrode 2, a reinforcing band i l,

and a supporting sleeve l2 of fiexible material, i. e. canvas, from which screen It depends. Shaking of screen I0 is accomplishedv by the reciprocal movement of rod l3 brought about inturn by the turning, of cam H by means not shown. In this embodiment of the invention,

screen l0 and connected parts are connected to ground by conductor l5.

The fibers are carried into the region of the electric field, that is, between electrodes l and 2,

by air flotation; fan i6, connected to the bottom and top of casing 5 by fiues I1 and i8, respec- -tively, being used to move the air through the' cilitating the movement of the fibers from the hopper into the air stream passing in flue II.

The manner in which the apparatus is operated in constructing piled surfaces is set forth in the following description. The material to be piled, say a sheet of paper, is coated with adhesive and placed upon electrode with the adhesive facing upwards, as shown at 23. The electrodes are now energized, the circuit indicated, to be later described, being used for that purpose. Fan I6 is started and fibers are added from the hopper l9 to the air passing in flue l1. Many fibers come from storage rather densely packed together and disintegration is necessary before they can be introduced into the electric field for deposition on material 23. The agitation provided by the fan and by passage through the fiues is sometimes sufficient to break up the masses of tangled fibers, but it has been found advantageous to supplement this action by further agitation on screen ill. some of the fibers brought to screen ill by the air stream passing infiue l8 immediately pass through screen I and electrode 2 and are deposited by action of the electric field existing between electrodes and 2 upon the adhesive covered material 23.

Some of the fibers reach screen ill in clumps, however, and pass through only after they have been agitated upon the surface of the'screen and blown with the passing air current.

In this particular embodiment of the invention the force of gravity and the kinetic energy furnished by the air stream both augment the elec tric forces in pushing or pulling the fibers down upon the surface of sheet 23. The air stream must turn at 90 degrees, however, as it approaches the surface of sheet 23 in order to pass around electrode l, as indicated by the arrows, and enter flue i1 beneath it; but this seems to be more beneficial than otherwise. The fibers that have been properly separated, charged and oriented are pulled down, definitely, to the surface and adhere to it because of the predominance of the electric forces over any sideward pull set up by the air stream. The fibers which tree or settle in loose masses over the surface of the pile are blown away by the air and carried into flue H to be again introduced, after further disintegration, for deposition. As pointed out above, the

screen comprising electrode .2 is of coarser mesh than screen I I); for example, the former may have 6 openings to the linear inch while the latter may have 8 or more. This is to assure the ready passage of fibers through electrode 2. But sometimes long and rough fibers will build up on screen 2, necessitating the shaking or brushing of this electrode." It is to advantage to keep electrode 2 free from complications and auxiliary members and in careful alignment, parallel to electrode I. This is best accomplished by supporting it as shown, but where shaking and the like must be resorted to, electrode 2 may be eliminated and the bottom surface of screen Hi can be made to function as the top boundary of the electric field.

- Fig. 2 illustrates apparatus in which the surface to be piled is held in vertical position. This construction has been found to have advantages when the fibers tend to .tree between the electrodes and/or become grouped in unattached masses over the uncompleted pile. Unattached fibers can be more positively blown from a vertical surface than from horizontal surfaces such as that shown in Fig. 1. The construction illustrated in Fig. 2 also makes possible the piling of surfaces while they are moving and permits of humidity control within the apparatus.

In Fig. 2, numeral 3| designates the electrode over which material 43, which may be a flexible sheet of fabric, is caused to pass while a. pile is built upon the surface thereof. Electrode 3| is maintained, preferably, at high potential and is supported by insulating means as indicated by member 31. Electrode 3| is opposed by electrode 32, made up of members 32' extending transversely and, in general, parallel to the surface of electrode 3|. Members 32' are positioned from' onehalf to one and one-half inches apart, depending upon electrical conditions, the velocity of the air passing, and other conditions. The lower edges of members 32', the edges closest to electrode 3|; are bent back or otherwise rounded to prevent corona discharge therefrom. With the edges thus rounded and spaced and. carefully aligned so as to be at an equal distance from the surface of electrode 3|, members 32' comprise. a boundary for any electric'field established between electrodes 3i and 32 that is not essentially different in its characteristics from that to be had with a fiat plate. Electrode members 32' are supported, by means not shown, so their upper edges are in alignment with the bottom, and open end, of wind box 35; and air leaving the wind box is directed, in an oblique direction, by members 32' towards the surface of electrode 3i. Within wind box 36 is a. fiber sifting device made up of flexible sleeve 38, screen 39 dependent therefrom, and an agitating device indicated by crank 40 and connecting rod 4|. H

The electrodes and supports just described are enclosed in a chamber or casing 35. Casing 35 is preferably'substantially air tight, but as it is diflicult, although not impossible, to handle material 43-within the casing, slots are made at 42 and 44 for the entrance and exit of the material. Casing 35 is ordinarily made of electric conducting material, grounded by conductor .34, but it is advisable in some cases to make it of non-conducting material, especially that part enclosing high potential electrode 3| as indicated at a, b, c and d. Side b can be built as a door through which electrode 3| can be inspected and positioned and the insulation thereabouts can be cleaned. Electric conductor 33 connects electrode 3| to energizing means outside the casing, such as that indicated in Figs. 1 and 4. It is held in insulated relationship with wall d of casing 35 by bushing 45.

- Air, orany suitable gas, is circulated through casing 35 by fan 50, connections to the fan being made by fiues and 52. Fibers are added to the air stream through hopper 53, the amounts added being controlled by measuring wheel 54. The characteristics of the circulating air, especially as regards humidity conditions, are controlled by adding conditioned air and releasing surplus air. Air drier than that of the atmosphere can be obtained by drawing air through drying chamber 55 which is connected to fiue 5| by flues 51 and 51', controlbeing secured by valve 58. Dehydra tion of the air is brought about by spreading calcium chloride over trays l8 and causing the air to pass over the chloride. The air in the system may be too dry in cold weather. 'Humidification can be secured by drawing air into the system through spray chamber 59, water provided by spray I being evaporated as the air .passes over bailles I. Valve 6! permits close regulation of the humidified air admitted. Conditioned air admitted for humidity correction replaces air already in the system and this is released through valve 3. The released air carries fibers in common with the other air in circulation and these are collected in bag filter i4, removed through closure 65, and returned to hopper 53. It has been found advantageous to so regulate valves 63 and 54 (or 62) and dampers 66 and. .61 that the pressure in casing is held at -or very slightly above atmospheric pressure. If the pressure is slightly above that of the atmosphere, air passes out slots 42 and 44, whereas at lower pressures it would enter through them. Of course, by suitable control means, gases for special purposes can be introduced into the system. .If the adhesive on material 43 is accompanied by solvents having vapors which may form explosive mixtures with air, such mixtures can be avoided by adding carbon dioxide or other non-supporter oi combustion in appreciable quantity. While ordinarily sparks are not present in the apparatus, improper control may cause the inadvertent presence of sparks and explosive mixtures of air and vapors are to be avoided.

- The material upon the surface of which ,a pile is to be constructed may be a fabric ordinarily supplied in roll form as indicated by roll 10. It is stretched over guide rolls ll, 12 and I3 and over electrode ii and slowly moved by suitable means such as rolls l5, 15 which have raised and. corrugated bands at the ends thereof to grasp the sheet 43 at the edges and draw it over the other rolls and permit it to be re-rolled as indicated at roll is. The adhesive may be put on v by various methods. The method illustrated consists of the use of trough IT with spreading edge 18 which presses upon or projects towards the fabric as it is stretched over adjustable member I9. The fibers are attached, in positions perpendicular to the surface of the fabric, for the most part, as thefabric moves over electrode 3|. The piled material is then finished as may be -necessary or desired. Driers and/or vulcanizers,

not shown, may be provided at location 30. A beater 8i and brush 82 remove non-attached or poorly attached fibers after the adhesive has become dry. Hoppers 83 and 84 collect loose fibers that may otherwise become scattered about the v operating room.

In operating the apparatus shown in Fig. 2 it is important that the fibers be separately floated in the air stream and be conducted into the electric field in this condition for deposition on the surface to be piled. The aggregates of fibers introduced through hopper 53 are broken up to a considerable extent by fan 50 which in- .and tend to "tree between the. electrodes. these unattached fibers remain over the uncompleted pile, further deposition of oriented fibers suit is easily ascertained. Many of the fibers reach the adhesive covered surface in oriented position; that is, perpendicular to the surface,- and become fastened at one end to that surface. Some ofthe fibers approach the surface sidewise for lack of suiflicient electric charge or some other reason, or become attracted to other fibers If ceases; but by controlling the velocity of the air stream, a removal of su'chfibers is realized and deposition of fibers continues until they are so thickly packed upon the surface of the material that the material is completely hidden and a pile factory. Too high a velocity of air in the elec tric field will move the charged fibers in a dif ferent direction from the direction the electric field tends to'move, them. But it canbe readily appreciated that a stream of air moving at a properly chosen velocity and preferably at an angle which causes the air stream to augment the force of gravity will keep the region of the electric field free of uncharged and massed fibers and permit the separated and charged fibers to be deposited individually into the pile.

The control of humidity 'has been mentioned above. The fibers commonly used in making piles, for example, fibers of rayon, silk, and cotton and animal hairs such as those comprising wool and rabbit fur, are -of small diameter and have great surface area as comparedwith their mass. They are, therefore; quickly and positively influenced by the moisture content of the me-' dium in which they are suspended. The conductivity, .at least the surface conductivity, of the fibers is increased by the sorbed moisture and this alters the rate of distribution of the charges upon the fibers-and the manner in which they are moved and oriented in the electric field. It has been found that when the relative humidity of the air carrying the fibers is below 40 percent the fibers are noticeably slower in depositing and forming a pile. A relative humidty above percent, on the other hand, tends to cause rapid deposition, but not .in an orderly manner; treeing and undesirable massing of the fibers result. With the means illustrated broadly in Fig.

2 and described-above, the air can readily be.

maintained with humidity values between 45 and '75 percent of saturation, a humidty range in which depositiomis quite satisfactory.

In the embodiment of the invention shown in moved upwards by action of the electric field, and deposited on an adhesive covered surface. Fan 85 for moving the air is rotated by motor 81 within ashort tube 86 which is supported by adjustable members 88, 88, within casing 89. Supported upon and above tube 86 is a hood 90 with a top 9! of metal screen or other suitableopen A mesh material, Within hood 90 'is a scraping I Fig. 3, the fibers are suspended in an air stream,

' projected upwards into an electric \field,j further mechanism 92 comprising a plurality of contact' members 93 which, upon rotation of mechanism 92, by means preferably outside casing 89 and not shown, pass in rubbing contact over the inner surface of screen 9|. A transverse plate 94 within tube 88 is for the purpose of preventing rotation of the air stream leaving tube 88.

An electrode 95 is suspended from cover '96 of casing 89 by members 91 which are mounted on springs 98. Electrode 95 can be moved downwards if sufiicient force is exerted upon it to overcome springs 98, but it cannot move upwards because of stops 99. An anvil Iwith a transversely extending slot I M is mounted on electrode 95. Within slot IOI is rapping member I02 which is dependent from rod I which is in turn dependent from yoke I08 which rides on cam I0'I. Rod I05 is vertically movable in bearings I08 and I09 and when yoke I05 drops oil the high point of cam I01, spring I03 causes hammer member I04, which is positively attached to rod I05, to strike strongly upon anvil I00 and suddenly move and vibrate electrode 95.

An electric field for the depositing of fibers can be established between screen 9| and electrode 95 if either of these members is properly insulated. But it has been found more convenient and more eflicient and in general safer to introduce an intermediate member IIO between the members mentioned. Member H0 is shown as a screen, preferably 01 one-quarter inch or coarser mesh, although closer mesh can be used if the screen is effectively shaken. Screen I I0 is bounded by a rounded band III and this is supported by a plurality of members H2 and H3 which can reciprocate in bearings H4 and II5 within insulating supports H6 and III, respectively. The insulators H6 and III are fastened by clamping members II 8 as closures over holes II9 and'I20, respectively, in the walls of casing 89. Member II3 passes completely through insulator III and so functions as an inlet conductor for electric current supplied through conductor I23 and as a connection to the agitating mechanism designated by numeral I2I. A, connecting link I22 of insulating material is inserted between member H3 and agitating mechanism I2I so the latter may be maintained at ground potential.

The apparatus shown in Fig. 3 is commonly used to build piles upon the surfaces 01' paper and textile fabrics. Roll I25 indicates a supply of cloth that is guided by rolls I26 and I2! to and from the under surface of electrode 95. Rolls I28, I28, in adjustable carriage I29, position travelling cloth sheet I25 as it is coated with adhesive from a spreading device I30 similar to those used in coating so-called oil cloth. The fibers or other pile forming elements are introduced into the apparatus through supply bln I3I, a plunger with handle I32 being used to force the fibers'downwards when necessary. Air, I .or gases for conditioning the air or other gaseous medium within the apparatus, can be brought in through pipe I33 from any suitable supply' as indicated by chamber I34.

In operating the apparatus shown in Fig. 3, the high potential side of a source of unidirectional current is connected to conductor I23, the other side being connected to conductor I24 and to ground. The devices, not shown, for drawing sheet I25 through the apparatus, are set in motion and adhesive is applied to said sheet by spreader I30. Motor 81 is' started and fibers are fed into the air current setup by fan 85. Scraper 92 is made to revolve. The volume and velocity of air passing through screen 9I is regulated by altering the speed of motor 81 and by altering the air inlet to the fan by raising or lowering sleeve 86 with adjustable supports 88, 88. It should be pointed out that when the fibers are easily disentangled and separated by the fan, 7

screen 9| and scraper 92 are not needed and can be removed, a funnel a few inches high on top of sleeve 86 being then used to direct the fibers towards the electrodes above.

Adjustments in the position of screen electrode H0 can be made through clamps II8, but in general the position of electrode I I0 is definitely fixed at from two and one-half to three and one-half inches below, and parallel to, electrode 95. Changes in the strength of the electric field can be made by controlling the electric circuit conditions. The voltage difference impressed between the electrodes, as described, is from 25,000 to 50,000 volts and the screen electrode H0 is commonly made negative except where it is advisable to alternate the polarity of the field.

As the fibers begin to deposit on sheet I25, the means, not shown, for rotating cam I0! is set in motion to turn cam I01 at from 20 to 80 R. P. M. This causes sheet I25 to be rapped rigorously by member I02 where it passes under slot IM and imparts a more gentle vibration to all of that portion of sheet I25 which is held against the under side of electrode 95. Any fibers not attached to sheet I25 by the adhesive are thus jarred away from the pile to be recirculated. In the use of this construction and with this method of operationit is an easy matter to cause the unattached fibers to leave the pile because the force of gravity pulls directly away from the pile surface and the horizontal components of the air stream forces sweep the fibers along. to the sides of the apparatus, down which they are carried to the fan inlet.

It is an important object in the present invention to energize the electrodes comprised in the apparatus described above in effective manner. An electric circuit for such purpose is diagrammatically illustrated in Fig. 1. A low voltage alternating current source I40, say at 220 volts and 60 cycles, is connected through a voltage control resistance HI and a double throw reversing switch I42 to a step up transformer I44. The

high potential terminals of the transformer are connected to stationary shoes I45 and I45, respectively, offmechanical rectifying switch I". The switch is turned by synchronous motor I in synchronism with the supply current, with the result that stationary shoes I48 and I49 of the rectifier are always connected to the high potential current supply at constant polarity, that is, one shoe is always positive and the other is always negative. Shoe I48 is shown connected through conductor I54 and dampening or loading resistance I52 and shunting switch I53 to ground 6 and the grounded parts of the pile forming apparatus through conductors 4 and I5. Shoe I49 is shown connected to insulated electrode I through conductors I55 and 3. Fibers can be most effectively charged, oriented, and deposited with an electric field of constant polarity and a direct or rectified current source is preferably utilized, therefore, in energizing the electrodes. But it has been discovered that, in the use of a constantly applied electric field, certain undesirable conditions become emphasized. Treeing of fibers, once begun, tends to continue and makes it necessary to operate the scouring air streams andrapping devices with great diligence. Also with a constantly applied potential a sheet of insulating material being piled becomes very strongly attracted to the electrode over which it is passing. It has been found that these tendencies can be checked if the polarity of the electric field is' occasionally reversed. This is done in the circuit of Fig. 1, for example, by operating reversing switch I42 with an automatic device,

used instead of a mechanical rectifier.

not shown, that causes the grounded side of the circuit, connected to shoe I48, to be .alternately negative, for example, for two to five seconds and then positive for one-half to two seconds. The high voltage electrode I is at opposite polarity to that of electrode 2 during the same periods, of course.

Very rapid reversals, in synchronism with the alternating current source, have been found advantageous at times. This condition is obtained by shifting rectifier I41 with relation to the revolvingfield of synchronous motor I50 by clamping adjustable coupling II in a different circumferential position. In this manner electrode I can be maintained, say, positive and at high potential, for most of the half cycle and negative and at lower voltage for a short part of the cycle. In other words, through what might be called a poor setting of the'rectifier, rectification is not complete and a short energization at opposite polarity follows or precedes each half wave of given polarity. Stoss or steep wave front impulses have also been used with good effect in some depositions. This condition is obtained by opening switch I53 and inserting a condenser I51 and a spark gap I56 into the circuit as shown. The Stoss circuit will be more effective if a load I58 requiring considerable current is placed across leads I54 and I55.

Vacuum tube or hot cathode reotifiers can be Fig. 4 shows the use of a single hot cathode rectifier I59 which will permit half wave energization at constant polarity. To effect reversal of polarity with this type of rectifier in the circuit,'the reversing means must be placed on the high potential side of the transformer as illustrated by the use of switch I60. Switch I60, made up of conducting members IBI supported by insulating member I62, will, upon rotation or upon oscilla-.

tion through 90 mechanical degrees, alternately connect terminal I63 of rectifier I59, which is always negative, With high potential lead I55 and with ground. In oscillating switch I60, a longer pause is made at one set of connections than at the other, thus permitting energization at one polarity for longer periods than at the other face by afilxing attenuated materials thereto comprising opposed electrode means insulated from each other, one of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, and means for introducing pile forming material into said gas stream.

2. Apparatus for forming a pile upon a surface by afiixing attentuated materials thereto comprising superposed electrode means insulated from each other, one of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, and means for introducing pile forming material into said gas stream.

3. Apparatus for forming a pile upon a surface by afiixing attenuated materials thereto comprising superposed electrode means insulated from each other, the upper of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode andIinto the electric field between said electrodes, and means for introducing pile forming material into said gas stream.

4. Apparatus for forming a pile upon a surface by aflixmg attenuated materials thereto comprising superposed electrode means insulated from each other, the lower of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, and means for introducing pile form-.

ing material into said gas stream.

5.. Apparatus for forming a pile upon a surface by afiixing attenuated materials thereto comprising opposed electrodes insulated from one another, means for establishing an electric field between said electrodes, means for passing a web of foundation material through said field adja-- cent one of said electrodes, means constituting a conduit for directing a gas stream between said electrodes, means for imparting motion to the gas stream in said conduit, means for introducing pile forming material into said gas stream and means. in said conduit for breaking up clumps of the pile forming material.

6. Apparatus for forming a pile upon a surface by aflixing attenuated materials thereto comprising superposed electrode means insulated from each other, the lower of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for agitating the foraminous electrode, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, and means for introducing pile forming material into said gas stream.

'7. Apparatus for forming a. pile upon a surface by afiixing attenuated materials thereto comprising opposed electrode means insulated from each other, one of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for passing a web of foundation material through said electric field adjacent the electrode opposing the foraminous electrode, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, and means for introducing pile forming material into said gas stream.

8. A method of forming pile-surfaced materials, which comprises establishing an electric rials, which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, suspending masses of pile forming materials in a gas stream, disintegrating said masses of pile forming materials by passing said gas stream through a foraminous member, and directing the gas stream contain- I ing the suspended material into the region of the electric field.

10. A method of forming'pile-surfaced materials, which comprises establishing an electric field between opposed electrode structures, posi-' between said electrodes, suspending pile formingmaterials in a gas stream, directing the gas stream containing the suspended material into the region of the electric field, and periodically alternating the polarity of the electric field with periods of constant polarity of at least about onehalf second.

12. A method of forming pile-surfaced materials, which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, suspending pile forming materials in a gas stream, directing the gas stream containing the suspended material into the region of the electric field, and periodically alternating the polarity of the electric field with a period substantially greater than that of commercial alternating current.

13. A method of forming pile-surfaced materials, which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, suspending pile forming materials in a gas stream, and directing the gas stream containing the suspendedmaterial through one of said electrode structures into the region of the electric field while agitating the electrode through which the gas stream passes.

14. A method of forming pile-surfaced materials, which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, suspending pile forming materials in a gas stream, directing the gas stream containing the suspended material through one of said electrode structures into the region of the electric field while agitating the electrode through which the gas stream passes, and periodically alternating the polarity of the electric field with periods of constant polarity of at least about one-half second.

15. In the production of piled surfaces by passing a stream of gas containing pile forming material adjacent an adhesive-surfaced foundation material positioned in an electric field, the

step comprising adding a conditioning medium to the stream of gas whereby the conductivity of the pile forming material is altered.

16. In the production of piled surfaces by passing a stream of gas containing pile forming material adjacent an adhesive-surfaced foundation material positioned in an electric field, the step comprising regulating the humidity of the gas stream to a predetermined degree.-

17. In the production of piled surfaces by passing a stream of gas containing pile forming material adjacent an adhesive-surfaced foundation material positioned in an electric field, the step comprising adding gaseous medium of predetermined humidityto said gas stream.

18. In the production of pile surfaces by passing a stream of gas containing pile forming material adjacent an adhesive-surfaced foundation material positioned in an electric field, the step comprising maintaining the humidity of the gas stream at a predetermined degree between about 40 percent and about percent relative humidity.

19. A method of forming piled surfaced materials, comprising establishing an electric field between opposed electrode structures, bringing pile forming fibers into said electric field adjacent an adhesive-surfaced foundation material, and controlling the electrical deposition of the fibers by controlling the surface conductively of the fibers.

20. In the production of piled surfaces by passing a stream of gas containing electrically charged pile forming material adjacent an adhesive-surfaced foundation material positioned in an electric field, the step comprising regulating the humidity of the gas stream to a predetermined degree.

21. Apparatus for forming a pile upon a surface by aflixing attenuated materials thereto comprising opposed electrode means insulated fom each other, one of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, means for introducing pile forming material into said gas stream, said foraminous electrode having openings adapted to break clumps of said pile forming material into individual fibers.

22. Apparatus for forming a pile upon a surface by aflixing attenuated materials thereto comprising opposed electrode means insulated from each other, one of said electrodes being foraminous, means for establishing an electric field between said electrodes, means for establishing a gas stream through said foraminous electrode and into the electric field between said electrodes, means for introducing pile forming material into said gas stream, and means cooperating with said foraminous electrode for breaking clumps of said pile forming material into individual fibers.

23. Apparatus for forming a pile upon a surface by aflixing attenuated materials thereto comprising opposed electrodes insulated from one another, means for establishing an electric field between said electrodes, means constituting a conduit for directing a gas stream between said electrodes, means for imparting motion to the gas stream in said conduit, means for introducing pile forming material into said gas stream and beating means in said conduit for breaking up clumps of the pile forming material.

24. A method of forming pile-surfaced materials which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, bringing pile-forming fibers into the electric field and periodically alternating the polarity of the electric field with periods of constant polarity of at least about onehalf second.

25. A method of forming pile-surfaced materials, comprising establishing an electric field between opposed electrode structures, bringing pileforming fibers into said electric field adjacent an adhesive-surfaced foundation material, and

controlling the electrical deposition of the fibers by controlling the conductivity of the fibers.

26. -A method of forming pile-surfaced materials, comprising establishing an electric field between opposed electrode structures, bringing pileforming fibers into said electric field adjacent an adhesive-surfaced foundation material, and controlling the electrical deposition of the fibers by controlling the moisture content of the fibers.

27. A method of forming pile-surfaced materials which comprises establishing an electric field between opposed electrode structures, positioning an adhesive-surfaced foundation material between said electrodes, bringing pile-forming fibers into the electric field and periodically alternating the polarity of the electric field with potentials of substantially different voltage in periods of alternate polarity.

.28. A method of forming pile-surfaced material which comprises establishing an electric field of periodically alternating polarity, positioning an adhesive-surfaced foundation material in said field and bringing comminuted fibrous material into, the field in condition to be deposited thereon, thereby to produce a uniform pile surface having the fibers oriented in endwise position on the adhesive surfaced material.

29. In the production of pile-surfaced material, the method which comprises feeding alon a predetermined path an adhesive-coated foundation-materia1 creating an electrostatic field of alternating polarity intersecting said path and sive-surfaced foundation material and means for introducingpile-forming fibers into said field.

31. Apparatus for forming pile-surfaced material comprising means for feeding along a predetermined path a foundation material, means for coating the foundation material with adhesive, means for creating an electric field of alternating potential intersecting said path and means for introducing pile-forming fibers into said field.

HARRY A. WIN'I'ERMUTE.

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