US2715585A

US2715585A - Electrostatic flocking procedures and apparatus

Info

Publication number: US2715585A
Application number: US215726A
Authority: US
Inventors: Samuel M Schwartz; Gross Daniel
Original assignee: Velveray Corp
Current assignee: Velveray Corp
Priority date: 1951-03-15
Filing date: 1951-03-15
Publication date: 1955-08-16
Anticipated expiration: 1972-08-16

Description

g- 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15 1951 4 Sheets-Sheet l Dan/Z425 Gross FF W6 ATT RNEY 6, 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOQKING PROCEDURES AND APPARATUS Filed March 15, 1951 4 SheetsSheet 2 k. Q| m Q @Q 1 WQ w? N ILI A INVENTOR Samuel M. Sckwami Zhznz' 0P0;

ATT RNEY g- 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15, 1951 4 Sheets-Sheet 3 Fig.5. 44215 7 v INVENTOR SamzzeZMSc'ka/afiiy 4 ORN E Y 6, 1955 s. M. SCHWARTZ ET AL 2,715,585

ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Filed March 15, 1951 4 Sheets-Sheet 4 l q- 1/29 2 1/29 123 60752 a- 3 i jfi i .162

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.DanzeZ 07101515 B Y United States Patent Office ELECTROSTATIC FLOCKING PROCEDURES AND APPARATUS Samuel M. Schwartz and Daniel Gross, Paterson, N. J., assignors to Velveray Corporation, New York, N. Y., a corporation of New York Application March 15, 1951, Serial No. 215,726 26 Claims. (Cl. 117--17) The present invention relates to flocking procedures and apparatus and it particularly relates to methods and means of electro-static flocking of various sheet materials.

Although not limited thereto, the present invention will be particularly directed and described in its application to the flock printing or to fabrics and particularly woven textile fabrics although it has a much broader application to the flocking or flock printing of other textile fabrics as well as sheet materials such as paper and plastic films.

In flock printing or in flocking of textile fabrics with finely divided or chopped up fibres such as rayon, nylon, cotton or other cellulosic or nitrogeneous fibres of natural or synthetic origin, it has been found that special controls and procedures are necessary. For example, these short relatively thin fibres are subject to altogether different laws in respect to their deposition and adherence to woven textile materials, than would be the case with granular particles such as those of an abrasive nature which do not too greatly differ in length, width and thickness.

In connection with chopped up and finely divided textile fibres, it has been found that in all cases no matter how line the subdivision has been, the length of the fibres is always many times and tremendously greater than the diameter of the individual fibres and it has also been found that upon deposition of such fibres upon the cloth or woven fabric which has been previously printed or impregnated with adhesive material, it is necessary that the fibres be aligned substantially parallelly before contact or coating with the still liquid or fluid adhesive.

In general it has been found that procedures which are applicable to granular materials are not general in application to chopped up fibrous materials or finely divided rayon fibres.

It is therefore among the objects of the present invention to provide a flock printing procedure or a flocking procedure and an apparatus therefor which is particularly applicable to the flock printing or deposition of finely divided or chopped up textile fibrous materials upon woven fabrics or other textile or sheet materials.

Another object of the present invention is to provide a novel electro-static deposition method and means particularly applicable to the aligned deposition of textile fibres in finely divided condition upon sheet materials.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

It has been found that the above objects may be most satisfactorily accomplished by application of an alternating potential to the space in which the flock or finely divided chopped up fibres are applied to the adhesive carrying woven fabric.

A very different result is obtained by application of.

the flocking of textile 2,715,585 Patented Aug. 16, 1955 high alternating voltages than would be ordinarily ob tained by the use of electro-static voltage procedures involving non-varying voltages.

It has been found most satisfactory to provide two electrodes, above and below the fabric being flock printed, and to cause the fabric to pass between this narrow gap Desirably the Generally a potential of between 20,000 and 45,000 volts may be applied from a transformer which will step up a normal volt or 220 volt alternating supply of 60 cycles.

Desirably the upper electrode is sieved or consists of an open grille and is grounded, and the flock is caused to pass through such upper electrode, after being sieved on to the upper side thereof.

The lower electrode may be connected to the step-up transformer.

Also it has been found desirable to have the upper in addition it has been found most satisfactory to place a dielectric plate between the base electrode and the fabric as it travels between the electrodes. For example, a glass plate of A1" thickness may be employed and this plate may cause a voltage drop thereacross of about 3,000 or 5,000 volts.

In connection with chopped up fibres there is a tendency toward a treeing and of sparking which is not normally experienced to a great degree with other types of finely divided particles or granulars.

To obtain satisfactory flock printing it is necessary that the voltage drop from one electrode to the other and the movement of the electrodes in respect to one another he so controlled that this treeing and sparking will be altogether eliminated.

It is among the further objects of the present invention to provide an electro-static flock printing procedure in which there will be substantially no irregularities or coat the entire fabric but only isolated or selected areas thereof to give a predetermined flock printed design.

111 spite of the unevenness of the air gap due to the fact that the flock and adhesive are carried at some positions and not others on the fabric, it is important that the dielectric effects and the voltage over the area being flock printed be maintained substantially uniform.

An important feature of the present invention resides in the fact that the humidity and temperature are maintained constant and that the humidity should never exceed 40% and desirably never over 25%.

It has also been found that a fairly high concentration of ozone gives most satisfactory qualities to the deposition and the fabric with results.

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the in vention, but it is to be understood that changes, variations and modifications can be resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

Fig. l is a top schematic plan view of the flocking apparatus according to the present invention showing the various controls and drivers.

Fig. 2 is a vertical side sectional view upon the line 2-2 of Fig. 1 upon the same scale as Fig. 1.

Fig. 3 is a side elevational view taken from the top' of Fig. 1 showing the controls at the side of the flocking machine.

Fig. 4 is a fragmentary transverse sectional view taken upon the line 4--4 of Fig. 2 showing the arrangement at the end of the flock screen, upon an enlarged scale as compared to Fig. 2.

Fig. 5 is a fragmentary transverse vertical sectional view upon the line 5--5 of Fig. 2 showing the upper electrode reciprocatory drive upon an enlarged scale as compared with Fig. 2.

Fig. 6 is a top plan view of the upper electrode taken from the line 6-6 of Fig. 2 and upon an enlarged scale as compared with Fig. 2.

Fig. 7 is a fragmentary vertical transverse sectional view taken upon the line 77 of Fig. 6 to show the cross-section of the grille elements and upon an enlarged scale as compared to Fig. 6.

Fig. 8 is a top plan view of the bottom electrode taken upon the line 8-8 of Fig. 2 and upon an enlarged scale as compared to Fig. 2.

Fig. 9 is a vertical sectional view on the line 9-9 of Fig. 8 of the bottom or lower electrode.

Fig. 10 is a diagrammatic side sectional view showing the upper and lower electrodes in position with the fabric and blanket passing between the same and with the flock being indicated as being applied to the fabric.

Referring to Fig. 2, there is shown a hopper A with a revolving agitator B and at the bottom of the hopper is provided a rotating brush C.

The rotating brush delivers the flock indicated by the arrows D upon the reciprocating screen E. The screen E delivers the flock, as indicated by the arrows F, upon the upper electrode G consisting of an open-work grid or grille. This grid or grille G is best shown in Figs. 6, 7 and 10.

Below the upper electrode or grille G is the lower electrode H, which is shown in greater detail in Figs. 8, 9 and 10.

The electrodes G and H together with the flock-feeding arrangement A-B-C-E are so enclosed in a chamber I which may be maintained at a predetermined temperature and humidity and if desired at a predetermined air pressure.

Passing into the chamber J in the direction indicated by the arrow K is the fabric L. This fabric L will have been previously printed with an adhesive material in an overall design or in the form of a decorative pattern.

As the fabric shown enters the chamber I, it is picked up by the blanket M, which will accompany it through the chamber.

The blanket M will pass over the glass dielectric plate N, which is positioned above the lower electrode H.

Referring specifically to Figs. 1, 2 and 3, the chamber I has the legs 8 resting on the floor 7 and supporting the bottom wall 9. The top wall 10 carries the upper portion 11 of the funnel of the hopper. The chamber I also has the side walls 12 and the

end walls

13 and 14.

The agitator B consists of two rods 15 which are connected together by the frame elements 16 at the end thereof.

The frame members 16 are mounted upon a central shaft 17 which extends through the side walls, as indicated at 18 and 19 in Fig. 1.

The shafts 17 are driven by the sprocket wheel 20 from the chain 21 (see Fig. 3).

At the bottom of the hopper A is the brush member C, which is mounted upon a shaft 22. The shaft 22 extends through the side walls 12. The shaft 22 is driven through the sprocket wheel 23 from the chain 24.

The brush C is sufficiently wide so as to fill the opening at the bottom of the hopper A. The brush will press at 25 upon the hopper wall 26 and at 27 upon the hopper wall 28. The hopper wall 28 has a deflector or bar at the short side thereof to flip the bristles of the brush B, shown in Fig. 2.

The brush C will deposit the flock, as indicated by the arrows D, upon the screen E.

The screen E is mounted at its end by the hanger 36, consisting of a flexible belt, from the bracket 37 on the top wall 10 of the chamber J.

The other end 38 of the screen E, as shown in Fig. 2, has a follower member 39, which is periodically struck by the eccentric 40.

The eccentric 41B is mounted upon the shaft 41, which also extends through the side wall 12. The shaft 41 is driven by the sprocket wheel 42 of the chain 43 (see Fig. 3).

As shown in Fig. 3, the

sprocket wheels

20, 23 and 42 of the chain drives 21, 24 and 43 are driven from the sprocket wheel 44. The sprocket wheel 44- is driven by the motor 45 mounted at 46 upon the top wall 10 of the casing I.

From the screen E the flock will fall, as indicated by the arrows F in Fig. 2, upon the upper electrode G.

The fabric L passes into the chamber I through the opening and passes out of the chamber through the opening 56.

Also passing into the chamber 1 through the opening 55 is the belt M, which will then pass out of the chamber at the opening 56.

The belt M is carried by the upper,

main rollers

57 and 58 and by the adjusting, tension and guide

rollers

59, 60, 61 and 62.

The roller 57 is mounted upon the shaft 63 at the front wall 13 of the chamber J.

The idler roller 62 is mounted upon the shaft 64, which is supported by the bracket 65 at the rear wall 14 of the chamber 1. The chamber wall 14 is reinforced by the channel iron 66.

On the brackets 67 are mounted the bearings 68 for the shaft 69 of the roller 58.

The transverse channel member 79 extends across the returning belt section 71 and is supported on the springs 72. The springs 72 react on the block 73, which is supported by the angle bracket 74 on the rear wall 14 of the chamber J. Above the belt section 71 is also the angle member 75 on the rear wall 14.

Inside of the rear wall 14 the roller 61 is mounted upon the shaft 75. The carrier belt M then extends downwardly, as indicated at 76, to the adjusting roller 66. The adjusting roller 6% is carried on the shaft 77.

The bearings of the shaft 77 may be adjusted upwardly and downwardly by the screw 73 connected to the manual adjusting handle 79. The screw 73 passes through the head 80 having the legs 81. The legs 81 are mounted at 82 upon the bottom wall 9 of the chamber 1. By means of the adjusting screw 78 it is possible to adjust the belt upwardly and downwardly and control the tension thereon at the point 83.

The adjusting roller 59 is provided with a shaft 84, which is adjustable by means of the screw 85. The screw 35 passes through the head 86, which is mounted by the legs 87 upon the supporting member 8 of the chamber 1.

The screw passes through the head 86 and has the adjusting wheel 88 to enabie variation of the tension upon the belt at the point 89.

The belt M will be driven together with the fabric L by the driving roller 57.

As is shown upon Figs. 1 and 3, the shaft 63 of the roller 57 carries the sprocket 95, which is driven by the sprocket chain 96. The sprocket chain 96 extends up to the counter shaft 97, which carries the driving sprocket 98, to the chain 96.

From the shaft 63 the drive extends through the sprocket chain 99 to the sprocket wheel 100 on the shaft 101 (see Fig. 3). The shaft 101 drives the chain 102. The chain 102 drives the sprocket wheel 103 on the shaft 104. The shaft 104 carries the conveyor 105 shown in Figs. 1 and 2 and in large scale in Fig. 4.

The conveyor 105 fits in the channel 106 positioned in the end 35 of the screen E.

The conveyor shaft 104 passes through the side wail 12 of the chamber J to the sprocket wheel 103. The conveyor 105 will normally move the flock, as indicated by the arrow 107, to the sleeve 108. The flock passing through the sleeve 108 will be dumped into the collector 109 outside the chamber wall 12. The collector 109 consists of a back held in position by the snap ring 110 on the collar 111. The collar 111 is mounted below the tube 108.

The cap 112 enables access to the openings 113 and The excess flock falling 011 the screen is thus disposed of and carried to the receiver 109, from which it may be re-used. The eccentric 40 will normally feed the flock toward the screw feed 105, which will receive the balance of the flock which does not fall through the screen E onto the upper electrode G.

The upper electrode G is shown in small scale in Fig. 2 and in larger scale in Figs. 5, 6, 7 and 10.

As shown in top view in Fig. 6, it consists of a grille or grid having the end frame members and the side frame members 121. Between the side frame members are a plurality of oblique bars 122 which are crossed by two right angle bars 123. The

bars

122 and 123 have a profile and cross section, as best shown in Fig. 7, which is wedge-shaped downwardly. The upper, narrow portions, as indicated at 124, have rounded edges 125 which pass into the outwardly flared side walls 120. This will enable the flock to flow readily downwardly, as indicated by the arrows 127. The base portions 128 of the bars 126 are widest, so as to establish a broad field and they have rounded corners 129. All

corners

125 and 129 are rounded to prevent any possible concentration of the electrostatic charge and any possible breakdown of the dielectric materials with resultant sparking.

The

edge frame members

120 and 121 have rounded or quarter cylindrical faces 130 with the

rounded corners

131, 132 and 133. On the sides of the plate are mounted the circular bars 134 which project, as indicated at 135 and 136, from both ends of the upper electrode G. These bars are positioned on the upper side of the electrode G and they pass between the

guide rollers

137 and 138.

As shown in Fig. 5, the

guide rollers

137 and 138 are mounted on the side frames 139, which in turn are mounted upon the base plate 140 supported on the angle irons 141.

One end of the upper electrode G is provided with the attachment 142 carrying the yoke 143. The yoke 143 consists of two parallel eyes which receive the pivot pin 144.

The pivot pin 144 connects to the pitman 145 which extends through the opening 146 in the wall 147 and through the opening 149 in the wall 12. The pitman 145 is driven by the eccentric 150 from the shaft 151.

The shaft 151, as shown in Fig. 2, is mounted in the bearings 152 and is driven by the bevel gear 153. The

bevel gear 153, as shown in Fig. 1, is driven by the bevel gear 154 and the shaft 155. The shaft 155 is carried in the bearings 156 on the wall 14 of the chamber I.

As a result, during the operation of the machine, the upper electrode G will be reciprocated laterally, as indicated by the double arrow 157, transversely of the direction of motion of the fabric L by the pitman 145.

The bottom electrode H, as shown in small scale in Fig. 2 and in large scale in Figs. 8, 9 and 10, consists of a relatively flat plate with the downturned edges 181 and the crossing

bottom ribs

182 and 183.

At the crossing points 184 there are provided openings 185 for fixing and supporting the lower electrode H. The lower electrode H is desirably supported upon the plate 186.

The plate 186 is supported by the insulation 187 mounted upon the angle members 189. These angle members are mounted upon the frame 190.

The electric wiring diagram is best shown in Fig. 10 and it includes one phase of an A. C. source 200 which is connected across the full winding of the variable autotransformer 201. The adjusting arm 202 of the variable transformer is connected to one side of the resistor 203, and the other side of the resistor is connected to one side of the primary winding 204 of the step-up transformer 205. The other end of the primary winding is connected by the line 206 to one side of the A. C. source.

One end of the secondary winding 207 of the step-up transformer is connected by the line 208 to the ground 209. From the other end of the secondary winding, the high tension line 210 may lead to the lower electrode H, placing an adjustable voltage with respect to ground thereon, which in the preferred form of the invention is adjusted to 28,000 volts R. M. S. The upper electrode G will then be connected by the line 211 to the ground.

If desired, the voltage may be applied to the upper electrode G and the lower electrode H to the ground. Optionally, a different type of step-up transformer and circuit may be employed so that part of the voltage will be applied to the upper electrode G and part to the lower electrode H, instead of applying the entire voltage of 28,000 volts (or higher or lower voltage as the case may be) to the one electrode.

The fabric L, in passing between the electrodes H and G over the glass plate N with the carrier belt M passing in the same direction, as shown in Fig. 10, will pick up the flock which flows downwardly through the interstices 210 between the bars 122.

The flock will adhere to the 211, and will stand upright at force.

The glass plate N serves as a dielectric to reduce the possibility of sparking or breaking down of the insulation.

The glass plate N, for example, in one instance may be one-half inch thick while the bottom electrode H is about one inch in depth.

The chamber I in a preferred form is about seven feet, six inches high, eight feet, six inches long and eightysix inches wide.

Desirably, the belt M and the wire screen E pitch slightly forwardly and downwardly in the direction of motion of the fabric.

The upper electrode G in one embodiment of the invention may be about fifty-five inches in length and about thirty-eight inches in width, with the spacing between the bars 123 being about eighteen inches and the spacing between the bars 122 being about two and onehalf inches. The

bars

120, 121, 122 and 123 may be one inch in depth and have their greatest width or maximum thickness of about one inch.

In operation, the high voltage will be applied with continuous sidewise reciprocation of the upper electrode G,

adhesive, as indicated at 212 under the electrostatic which will determine when there will be no trending and no uneven dispersal of the flock.

The oblique bars 122 and 123 will at all times pass at such an angle over the fabric L that there will be no tendency toward striping or uneven distribution of the flock.

While there has been herein described a preferred form of the invention, it should be understood that the same may be altered in details and in relative arrangement of parts within the scope of the appended claims.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

1. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes.

2. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said feed including a belt passing continuously between said upper and lower electrodes.

3. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said high voltage being applied to one electrode and the other electrode being grounded.

4. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, one of said electrodes being provided with means to laterally reciprocate the same transversely of the material to be flocked.

5. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a lattice-work having a plurality of bars extending obliquely to the direction of feed of the material to be flocked.

6. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, and a glass plate positioned above said lower electrode between the material to be flocked and the feed for the material to be flocked.

7. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode, said upper electrode consisting of a plurality of cross bars of wedge-shaped cross section with their sides diverting downwardly and with rounded corners and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, and an enclosure for said upper and lower electrodes to enable a constant moisture content and humidity to be maintained adjacent to said electrodes.

8. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a latticework having bars of trapezoidal cross section which are widest at their bottom edges and said lower electrode consisting of a solid plate, the upper electrode being grounded and the lower electrode being connected to the alternating voltage source.

9. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said high voltage being applied to both electrodes and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

10. A method of flock printing fabrics which comprises passing a fabric while depositing flock thereon between two metal plates, said plates being arranged one above the other and the upper plate being an open grille-work both of which metal plates are subjected to a high alternating voltage, said fabric and metal plates being positioned horizontally and said metal plates serving as high potential static charge electrodes and said flock being screened above said upper electrode and being caused to pass through the interstices of said upper electrode onto said fabric.

11. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, one of said electrodes being provided with means to reciprocate the same longitudinally of the material to be flocked and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

12. A flock printing machine comprising a feed for the material to be flocked, a feed for the flock, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a latticework having a plurality of bars extending transversely obliquely to the direction of feed of the material to be flocked and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

13. A flock printing machine comprising a feed for the material to be flocked, a feed for the flock, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a lattice-work having a plurality of spaced parallel wedge-shaped bars extending obliquely to the direction of feed of the material to be flocked and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

14. A flock printing machine comprising a feed for the material to be flocked, a feed for the flock, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a latticework having bars of trapezoidal cross section which are widest at their bottom edges and said lower electrode consisting of a solid plate, the lower electrode being connected to a source of a high alternating current voltage and the upper electrode being grounded and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

15. A flock printing machine comprising a feed for the material to be flocked, flock delivering means, an upper electrode and a lower electrode spaced apart, said feed carrying the material to be flocked between the electrodes, and means to apply a high alternating voltage across said electrodes, said upper electrode consisting of a latticework having bars of trapezoidal cross section which are widest at their bottom edges and said lower electrode consisting of a solid plate, the alternating current voltage applied across the upper and lower electrodes with the upper electrode being grounded and a reciprocating screen positioned above said upper electrode and below the flock delivering means, said screen being uncharged.

16. A flock deposition electrode system comprising an upper metal grille plate serving as an upper electrode, a lower metal plate parallel to said grille plate and serving as a lower electrode, intervening rubber and glass plates, the material to receive the flock being positioned between the upper metal electrode and the lower rubber and glass plates which are positioned above the lower electrode.

17. The system of claim 16 in which the grille plate is provided with reciprocatory means.

18. The system of claim 16 in which the upper metal grille plate is provided with a series of obliquely arranged transverse bars forming an open grille plate.

19. An electrostatic flocking apparatus comprising an upper oblique-bar grille reciprocating electrode, a lower solid plate fixed electrode, a transformer the output ends of which are connected respectively to the upper and lower electrodes, an upper reciprocating screen to screen the flock onto the upper electrode and a fabric carrier to pass between the upper and lower electrodes.

20. The apparatus of claim 19, said grille being formed of bars which are divergent downwardly.

21. The apparatus of claim 19, a fixed glass plate being positioned between the fabric carrier and the lower electrode.

22. The apparatus of claim 19, said upper electrode being provided with means to reciprocate said electrode laterally of the direction of movement of the fabric carrier.

23. The apparatus of claim 19, said upper grille being provided with side supporting and guiding bars and guide rollers to guide said bars to assure lateral reciprocation of said grille electrode.

24. A process of electrostatically depositing flock upon a fabric which has been printed with adhesive in a flocking apparatus which comprises an upper uncharged reciprocating screen, an intermediate lower grille-like open electrode, said screen, glass plate and metal electrodes being all positioned horizontally and parallel to each other, the step which comprises passing the fabric to be flocked horizontally between the glass plate and the open electrode whilst causing screen flock to flow through the openings in the grille-like open electrode onto the fabric and simultaneously applying a high reciprocating static charge of the order of between 20,000 to 45,000 volts to the electrodes.

25. The process of claim 24 is of quarter inch thickness and across of 3000 to 5000 volts.

26. A method of flock printing fabrics which comprises passing a fabric while depositing flock thereon between two metal plates, said metal plates having an intervening glass plate, one of which metal plates is grounded and the other of which metal plates is subjected to high alternating voltage, said plates being arranged one above the other and the upper plate being an open grille-work, said fabric and metal plates being positioned horizontally and said metal plates serving as high potential static charge electrodes and said flock being screened above said upper electrode and being caused to pass through the interstices of said upper electrode onto said fabric.

in which the glass plate has a voltage drop there- References Cited in the file of this patent UNITED STATES PATENTS 2,173,032 Wintermute Sept. 12, 1939 2,187,624 Melton et al J an. 16, 1940 2,356,489 Amstuz Aug. 22, 1944

Claims

10. A METHOD OF FLOCK PRINTING FABRICS WHICH COMPRISES PASSING A FABRIC WHILE DEPOSITING FLOCK THEREON BETWEEN TWO MATAL PLATES, SAID PLATES BEING ARRANGED ON ABOVE THE OTHER AND THE UPPER PLATE BEING AN OPEN GRILLE-WORK BOTH OF WHICH METAL PLATES ARE SUBJECTED TO A HIGH ALTERNATING VOLTAGE, SAID FABRIC AND METAL PLATES SERVING AS HIGH TIONED HORIZONTALLY AND SAID METAL PLATES SERVING AS HIGH POTENTIAL STATIC CHARGE ELECTRODES AND SAID FLOCK BEING SCREEND ABOVE SAID UPPER ELECTRODE AND BEING CAUSED TO PASS THROUGH THE INTERSTICES OF SAID UPPER ELECTRODE ONTO SAID FABRIC.