US3419413A - Method of coloring pile fabrics - Google Patents

Description

Dec. 31, 1968 F. A. EUFORBIA METHOD OF COLORING PILE FABRICS Sheet Filed Oct. 28, 1965 FELIX AVEUFOIZBIA ATTORNEYS 31, 1% F. A. EUFORBIA 3,419,413

METHOD OF COLORING FILE FABRICS Filed 001,. 28, 1965 Sheet 2 of 2 INVENTORI FELIX A. EUF-ORBlA ATTORNEYS Uited States Patent 3,419,413 METHOD OF COLORING PILE FABRICS Felix A. Euforbia, Greensboro, N.C., assignor to Foremost Screen Print, Inc., Stokesdale, N.C., a corporation of Delaware Filed Oct. 28, 1965, Ser. No. 505,516 Claims. (Cl. 11738) ABSTRACT OF THE DISCLOSURE lateral spreading of the colorant to obtain the final design of a predetermined size.

This invention relates to the art of obtaining colored or printed designs on pile fabrics such as tufted or Woven, looped, mapped or cut pile fabrics, including carpet, rug, blanket and terry fabrics, and is especially concerned with effecting the coloring of very thick pile materials to substantially the base of the piles for obtaining depth of color comparing aesthetically favorably with predyed pile yarns.

Many and varied attempts have been made heretofore to print on pile fabric surfaces. While some methods or apparatuses of the prior art have been successful in producing printed design areas on the pile fabrics, considerable difficulties have been experienced in effecting substantial penetration of the pile with the ink, especially in very small or narrow areas and particularly in deep pile. One known method has included immersing each of a plurality of pile areas in liquid coloring matter or ink contained in configured receptacles. However, such a method is expensive and time consuming, requires the manufacture and storing of many different shaped receptacles and becomes impractical in printing very small or narrow pile areas.

The application of suction to the lower surface of a pile fabric during the application of liquid pigments or dyes to the pile surface through a printing screen is also known, but requires bulky and expensive equipment not normally required and has not, to my knowledge, been effective to cause the desired penetration of ink to the base of high pile with proper line definition, particularly in the coloring of very small or narrow design areas.

Attempts have been made to force ink into pile utilizing successive screens or stencils beneath which the pile fabric was advanced in a stepwise manner with ink distributing rollers moving across and against the screens to distribute ink through permeable areas of the screens while applying heavy downward pressure to the screens and to the pile therebeneath. However, such attempts have not been successful to my knowledge because, if sufficient downward pressure is applied to a printing screen by ink distributing means such as to force ink to penetrate downwardly into pile beneath the screen, an objectionable excessive and uneven lateral distribution of the ink occurs between the screen and the face of the pile so the required definition of colored designs on the pile cannot be obtained. The lateral distribution of ink at narrow design areas is particularly objectionable, especially in multicolor printing, because the color printed at one screen may be overlapped, or possibly hidden, by the color printed on a juxtaposed pile area at a succeeding screen; i.e., the colored designs would be improperly registered and of blurred appearance.

It is therefore an object of this invention to provide a novel, economical method of printing designs on a thick or high pile fabric and which is particularly effective in printing very small or narrow design areas with the ink effectively penetrating the pile at such areas to a depth heretofore unattainable to my knowledge.

It is another object of this invention to provide a method of printing designs on fabric having high projecting pile which comprises applying ink to predetermined areas of the pile, and thereafter compressing the pile with the ink thereon to force the ink to penetrate from the face of the pile substantially to the base of the pile.

The method, as disclosed in detail hereinafter, includes positioning a projecting pile surface beneath a screen having one or more permeable areas therein, after which a squeegee blade is moved along and against the screen for distributing colored ink thereover and through the permeable areas to deposit ink on and form corresponding design areas on the pile surface and, thereafter, the pile surface is removed from beneath the screen and compressed under heavy pressure to force the deposited ink thereon to penetrate the pile surface substantially to the base of the pile.

Some of the objects having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which- FIGURE 1 is a schematic perspective view of an embodiment of apparatus for carrying out the method of this invention; 1

FIGURE 2 is an enlarged side view of the upper portion of the pile compressing apparatus in the right-hand portion of FIGURE 1;

FIGURE 3 is an enlarged fragmentary detail showing how the pile is compressed as it passes through the squeeze rolls;

FIGURES 4 and 5 are fragmentary plan views of a fine-line design area on the pile surface of a pile fabric before and after the ink has been forced to penetrate the pile;

FIGURES 6 and 7 are enlarged sectional views taken along lines 6-6 and 77 in respective FIGURES 4 and 5;

FIGURE 8 is a fragmentary vertical sectional view taken substantially along line 8-8 in FIGURE 1 and illustrating a typical squeegee for distributing ink along the corresponding pinting screen and FIGURE 9 is a schematic view showing an alternative embodiment of means for compressing the pile surface.

Referring more specifically to the drawings, apparatus for carrying out the printing method according to the invention may comprise a stencil printing or screen printing system having one or more printing stations for printing different colored design areas on fabric therebeneath, there being two such stations P, P shown successively arranged in FIGURE 1 which may be of conventional or other construction. Fabric 10, having projecting pile surfaces or sections 11 thereon, may be drawn from a suitable supply roll 12 along the upper surface of a table 13 by an intermittently driven endless conveyor or belt 14 whose upper run, with pile fabric 10 thereon, extends between the printing stencils or screens 15, 16 or stations P, P and table 13, through the space between squeeze rolls 20, 21 of a novel pile compressing unit 22, and into a suitable finishing means 23 which may take the form of a dryer or ager, or which may be arranged to subject the fabric to additional wet treatments according to the characteristics of the ink or colorant applied to the pile surfaces 11, as is well known in the art.

The term ink or colorant is used herein to indicate generically any type of colored solution or paste suitable for use in stencil printing or screen printing intricate design areas on textile fabric or pile surfaces thereon and including pigments in emulsion form or soluble dyes, such as vat dyes, mixed with a starch or flour paste, or with gum paste. Pigments are preferred in many instances because, after the fabric has been printed with pigment emulsion and dried, further finishing treatments may not be required. However, further treatment is required after printing with soluble dyes so as to remove starch or other material previously mixed with the dye.

Conveyor 14 may be mounted on rollers 25, 26 and may be driven by any suitable indexing drive means well known in the art to advance successive pile surfaces 11 into registration with printing stations P, P, allowing time between successive advancements of conveyor 14 for application of ink to corresponding pile surfaces at printing stations P, P. As shown in FIGURE 1, the indexing drive means may include a suitably controlled single-revolution clutch means 30 for intermittently transmitting rotation from a motor 31 through belt and pulley means 32 to conveyor roller 25.

Printing stations P, P comprise respective stencils or screens made from woven cloth of nylon, silk or the like which is impermeable by the ink being used with the exception of permeable pattern areas or openings 36, 36' formed in the screens. Masses of ink C, C are distributed over the respective screens and through pattern areas 36, 36' onto pile surfaces 11 therebeneath by respective squeegees 40, 40' which are shown as being of the blade type which are preferable over rollers because, as is well known, squeegee blades effect a clearer definition of inked designs than rollers, especially in fine-line work. As shown, the squeegees are moved across and against screens 35, 35' by suitable linkages 41, 41 operating in timed relation to stepwise advancement of conveyor 14, as is well known. Both Squeegees 40, 40' should comprise a thin resilient blade, made from rubber or the like, such as is shown in FIGURE 8, to insure that the squeegees cause effective penetration of the ink through all permeable pattern areas 36, 36', and, especially, through very small or narrow pattern areas such as areas 36 of screen 35, for example.

Screens 35, 35' are mounted in taut condition on suitable frames 43, 43 which are raised during each advancement of conveyor 14 and fabric by suitable means of well known construction generally designated at 44, 44', the screens 35, 35 being lowered against corresponding pile surfaces during the dwell between successive advancements of conveyor 14. With the exception of pile compressing unit 22, the apparatus heretofore described may be conventional and, therefore, a detailed illustration and description thereof is deemed unnecessary. However, suitable means for advancing the fabric 10, raising and lowering screens 35, 35 and reciprocating Squeegees 40, 40' in proper timed relationship are disclosed more in detail in Gorners U.S. Patent No. 1,815,504 dated July 21, 1931, to which reference is made by way of example.

According to the method of the instant invention, the essential novel step in effectively coloring predetermined areas of the projecting pile surface substantially to the base of the pile resides in compressing the pile surface after ink has been applied to predetermined areas of the pile surface at a printing station or stations and following removal of the pile surface from the printing station or stations, and wherein the magnitude of such compression is such as to force the ink to penetrate from the face of the pile surface substantially to the base of the projecting pile. Since compressing the pile forces ink at the tips thereof to penetrate downwardly into the pile, this improves the hand and feel of the pile fabric at the design areas. The pile compressing unit 22 is one representative embodiment of means for compressing successive pile surfaces 11 and comprises a frame including a pair of standards 50 spaced forwardly of printing stations P, P adjacent opposite sides of conveyor 14 and in which reduced opposite ends of lower squeeze roll 21 are journaled.

Bearing blocks 51 are guided for vertical movement in bifurcated upper portions of standards 50 and have reduced opposite ends of upper squeeze roll 20 journaled therein. As illustrated, each bearing block 51 is connected to a ram or piston rod 52 of a fluid motor or double-acting fluid cylinder 53 fixed on a bridging upper portion 54 of the corresponding standard and having a piston 55 therein to which the upper end of the corresponding piston rod 52 is connected. Upper and lower ends of cylinders 53 may be connected to a suitable source of fluid pressure, not shown, by means of respective upper and lower conduits 56, 57. A suitable four-way valve 58 may be interposed in conduits 56, 57 so roll 20 may be raised and lowered at the will of the operator. In this arrangement, it is desirable that piston rods 52 apply downward pressure of from about 2500 to 3500 pounds per square inch to upper squeeze roll 20. However, a gap G is formed at the nip of rolls 20, 21 (see FIGURE 3), due to adjustable limiting means which may comprise a screw 60 threaded into each standard 50 at the bottom of its bifurcated upper portion and against which the corresponding bearing block 51 is normally held by piston rod 52. Thus, it can be seen that the width of gap G may be readily adjusted by adjusting screws 60. Each screw 60 may be provided with a lock nut 61. The width of gap G should be such that roll 20 is supported by the pile of fabric 10 during movement of the fabric through the squeeze rolls. In other words, the width of the gap should be substantially less than the height of the pile combined with the thickness of the fabric base and the belt 14. The gap G aids in the feeding of the fabric 10 into the squeeze rolls. Particularly, maintenance of gap G prevents upper squeeze roll 20 from bouncing and smearing the pile sections 11 as they enter and leave rolls 20, 21. In practice, it has been found that the ideal width of gap G without fabric extending therethrough can best be determined empirically, since the width of gap G may vary according to the type of yarn of which the pile is formed, the type or viscosity of printing ink applied to the face of the pile, and the density and height of the pile. For example, in processing a fine denier filamentary or staple pile surface, in which the pile yarn was made of textile filaments or fibers in the range of about one-thousandths to twenty-thousandths inch diameter and the height of the pile was in the range of about threeeighths to three-fourths inch, the gap G was about onesixteenth inch wide, plus the combined thickness of the fabric base and conveyor 14. For processing a coarser pile made from pile yarns in the range of about twentyfive thousandths to three-sixteenths inch diameter with a pile height of from one-half to one inch, the gap G was about three-sixteenths inch wide plus the combined thickness of the fabric base on conveyor 14. The amount of downward force applied to roll 20 is not critical as long as it is sufficient to insure sufiicient compression of the pile to cause penetration of ink substantially to the base of the pile.

Any suitable means may be provided for driving squeeze rolls 20, 21 at about the same surface speed as, and at the same time as, conveyor 14. As shown, pulleys 65, 6, fixed on squeeze rolls 20, 21, are engaged by an endless belt 67 held taut by an adjustable idler 70, and pulleys 71, 72, 73, 74, endless belts 75, 76 and a jack shaft 77 serve to connect bottom squeeze roll 21 to the output side of clutch means 30.

The amount of ink deposited on the pile surfaces at each printing station P, P is determined by the viscosity of the ink C, C and the angular position of squeegees 40, 40', as is usual. The amount of ink required to be deposited at stations P, P should be accurately determined empirically for a given type and construction of pile fabric so the compressing unit 22 will force all the ink previously deposited to penetrate substantially to the base of the pile without leaving excess reidual ink on the tips of the piles. However, since the ink is wet during the compressing of the pile, a thin film of ink may adhere to upper squeeze roll 20 and should be removed therefrom so that it is not redeposited on the pile surface. Accordingly, the periphery of roll 20 is engaged by one or more doctor blades 78, there being two such doctor blades shown in FIGURE 2 suitably adjustably secured to and extending between standards 50. Any ink scraped off roll 20 may be occasionally manually or automatically wiped off blades 78.

In the method described up to this point, it can be appreciated that, in the interim between successive advancements of conveyor 14 and fabric 10, screens 35, 35 are lowered against corresponding pile surfaces 11, and Squeegees 40, 40 are moved across screens 35, 35 to distribute ink of the desired viscosity across the screens and through respective permeable pattern areas 36, 36' to form respective, different colored design areas 36A, 36A (FIGURE 1) of ink on the corresponding pile surfaces. Thereafter, screens 35, 35 are raised, and conveyor 14 advances fabric another step to expose the pile surface 14 upon which ink C' was last printed at station P.

The operation of printing stations P, P is then repeated. As each advancement of conveyor 14 occurs, a pile surface 11, to which ink has been previously applied, passes through squeeze rolls 20, 21 so the pressure of upper squeeze roll against the pile surface compresses the same to some extent and forces the ink, which is still wet, to penetrate from the upper face of the pile to the base thereof. In the course of compressing the pile with ink thereon, although most of the ink is forced downwardly toward the fabric base, a small proportion of the ink is spread laterally so the ultimate size of the design areas on the pile surfaces is slightly greater than the size they were initially formed at printing stations P, P. In instances in which the design areas are quite large and/ or close registration of adjacent design areas is unnecessary, or if the entire pile surface is to be of a solid color, the small amount of lateral spreading of the ink effected by compressing the pile is not objectionable and generally would not detract from the aesthetic quality of the fabric, because the ink previously has been so applied to the pile surface as to form sharp, clean design areas thereon and the compressing of the pile by means of a hard smooth surface causes substantially uniform spreading of the ink in all lateral directions.

However, when relatively close registration of adjacent design areas is required, or design areas are to be quite small, or fine-line narrow design areas of as little as three thirty-seconds inch wide or less are to be formed, such as the areas 36A of FIGURES 1 and 5, I have compensative- 1y reduced the size of, or under-cut, the pattern areas 36 in screen by about one thirty-second to one-sixteenth of an inch depending upon the height and density of the pile to be printed. Thus, upon initially applying ink to the pile at printing station P, the narrow-line design areas 36A are of somewhat lesser width than the desired ultimate width thereof. Upon subsequently compressing the pile surface by passing the fabric through squeeze rolls 20, 21, for example, the design areas 36A are spread laterally to become the desired ultimate width. One of the design areas 36A is shown on a portion of a corresponding pile surface 11 before and after compression of the pile surface in respective FIGURES 4 and 5 wherein it will be observed that the lines of design area 36A are quite narrow in FIGURE 4; e.g., about three sixty-fourths inch wide, and the lines of the same design area 36A, as shown in FIGURE 5 after compressing the pile, are about three thirty-seconds inch wide. This phenomenon is further illustrated on a larger scale in FIGURES 6 and 7. In FIGURE 6 it will be observed that the ink is deposited in a narrow layer upon the pile 11 and penetrates only the tips of the pile tufts there beneath. After compressing the pile, however, it will be observed in FIGURE 7 that the ink has spread laterally in the design area 36A and penetrates the pile from the tips of the pile tufts substantially to the base thereof.

As is well known, the lesser the density of the piles, the longer the pile tufts, and the softer the pile surface, the greater is the tendency for the piles to bend so their free ends may lay generally parallel to the lateral plane of the fabric, such as is shown in FIGURES 3, 6 and 7. Although the piles are shown bending or inclining in FIG- URES 3, 6 and 7, it will be appreciated that there are many pile fabrics whose pile tufts are so densely arranged or are made of such pile yarns that they will not normally be inclined in the manner illustrated in FIGURES 3, 6 and 7. In the case of pile fabrics whose piles remain substantially erect, it is apparent that they will be erect both before and after they are compressed. As is the case with the particular type of fabric illustrated in FIGURES 6 and 7, the clear definition of color design areas is also obtained when processing substantially erect-pile fabrics in accordance with the method of this invention. In most pile fabrics whose piles bend substantially as illustrated in FIGURES 3, 6 and 7, most of the piles naturally bend in the same direction. It has been found that the uniformity of dispersion of the ink in the design areas and clear definition of the design areas of such bent-pile fabric is improved by advancing the fabric through squeeze ro'lls 20, 21 with the tips of the piles pointing toward the direction of movement of the fabric so the ink is forced toward the bases of the piles rather than toward the tips of the piles. In some bent-pile fabrics, the piles do not lay generally in the same direction and, therefore, I have provided suitable means for brushing such fabrics and which may comprise a rotary brush (FIGURE 1) suitably journ'aied on table 13 to extend across and above conveyor 14 nearwardly of printing station P so as to engage and comb the pile surfaces 11 in the direction of advancement thereof. Brush 80 may be provided with stiff bristles 81, as shown, or with card clothing wire or any other suitable covering effective to cause the piles to lay in the direction of advancement thereof along conveyor 14. Brush 80 may be driven at such speed as to effect the desired brushing of the piles by any suitable drive means. As shown, pulley and belt @means 83 serve to connect conveyor roller 25 to brush 80 so brush 80 is rotated only during each advancement of fabric 10. Brush 80 may be removed or omitted in instances in which the pile surface need not be brushed.

While the squeeze roll arrangement of FIGURES 1, 2 and 3 is a preferred embodiment of pile compressing means for carrying out the method of this invention, it is contemplated that other types of pile compressing devices may be employed. For example, another type of pile compressing unit 22A is shown schematically in FIG- URE 9 which may be used in place of the compressing unit 22 in FIGURE 1. Referring to FIGURE 9, conveyor 14 with pile fabric 10 thereon is shown positioned upon table 13. Pile compressing unit 22A comprises a vertically movable substantially horizontal platen or pressure plate carried by a ram or piston rod 91 connected to a piston 92 in a double-acting cylinder 93. Cylinder 93 is fixed to a cantilever frame 95 which extends outwardly and then downwardly and is suitably secured to table 13. Upper and lower ends of cylinder 93 may be connected to a suitable source of fluid pressure, not shown, by means of respective conduits 96, 97. A suitable four-way valve 98 may be interposed in conduits 96, 97 to control the rais ing and lowering of platen 90. Valve 98 may 'be operated manually or automatically to move platen 90 downwardly in the interim between successive advancements of conveyor 14 and to raise platen 90 during each advancement of conveyor 14. It can be seen that platen 90 will compress the pile and force the ink thereon to penetrate substantially to the base of the pile each time platen 90 is moved into pressure engagement with a previously printed pile surface therebeneath. Suitable abutments 100 may be provided on table 113 in FIGURE 9 to limit downward movement of platen 90, if desired.

Although it is preferred that squeeze rolls 20, 21 of pile compressing unit 22 are provided with smooth, hard, cylindrical peripheral surfaces, either or both squeeze rolls 20, 21 may be provided with yieldable surfaces, if desired, provided that such surfaces are capable of performing the desired function of squeeze rolls 20, 21 to compress the pile surface and force the ink to penetrate the pile to the base thereof without distorting the design areas printed thereon.

In the drawings and specification there have been set forth preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. A method of obtaining colored designs even of a very intricate nature on pile fabric such as pile rugs wherein the colored design extends substantially throughout the depth of the pile and wherein the height of the pile is at least about inch, said method including screen printing colorant in a predetermined design onto the face of the pile fabric with the design being undersize as compared to the final design desired and wherein the printed colorant extends substantially less than the depth of the pile, thereafter moving the screen-printed fabric to a compression station and directing the same through a pair of squeeze rolls to drive the colorant downwardly substantially throughout the depth of the pile while effecting a lateral spreading of the colorant to obtain the final design of a predetermined size, and wiping the squeeze roll contacting the face of the fabric during passage of the fabric through the rolls to remove residual colorant therefrom to avoid color interference with the screen-printed design.

2. The method of claim 1 wherein the screen printing of colorant onto the face of the pile fabric takes place at at least two stations and wherein different colorants are applied at the respective stations.

3. The method of claim 1 in which the pile fabric is passed through the squeeze rolls with the pile of the fabric inclined generally toward the direction of movement of the fabric.

4. The method of claim 1, which includes spacing the squeeze rolls apart from each other to form a gap between the rolls of a dimension less than the thickness of the pile fabric for facilitating initial threading of the pile fabric between the rolls and for facilitating applying the desired pressure to the pile fabric passing therebetween.

5. The method of claim 1 in which the step of screen printing includes moving a squeegee blade against a mass of colorant and across and against a screen positioned against the pile face of the fabric.

References Cited UNITED STATES PATENTS 1,771,341 7/1930 McCollum 11738 1,821,302 9/1931 Gorner 101129 X 2,135,711 11/1938 Hiers. 2,220,589 11/1940 Unger. 2,816,811 12/1957 Tillett et a1 11737 3,121,642 2/1964- Biskup 117-15 RALPH S. KENDALL, Primary Examiner.

A. M. GRIMALDI, Assistant Examiner.

U.S. Cl. X.R.

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