Transfer printing method

Abstract

A method is disclosed for transfer printing background color and an ink pattern on opposite faces of a web of grey goods double knit from a synthetic material.

Description

For many, many years it has been conventional to apply a pattern or color to fabric by use of dyes. The use of dyes creates an environmental pollution problem. In accordance with the present invention, the pattern or color to be applied to the fabric is accomplished by printing the pattern or color on opposite faces of a web of grey (greige) goods double knit from a synthetic material. The word "grey" is a misnomer and does not mean color although the web of fabric may be colored white, greyish-white, brownish-white, etc. The term "grey goods" in accordance with the present invention refers to an unfinished fabric which has been scoured to remove any oil which may have been added to facilitate the knitting operation and which has been heat set so as to stabilize the filaments from which the web of fabric was double knit.

The color and or pattern to be applied to the web of fabric is first applied to a web of paper. Thereafter, the color and/or pattern is transferred from the web of paper to one face of the web of double knit grey goods. Thereafter, color and/or pattern is applied from a different web of paper to the opposite face of the double knit grey goods. The color and/or pattern is printed on the faces of the web by transferral from the webs of paper while the webs are in intimate frictional contact and subjected to heat and pressure.

The pattern or color applied to one face of the grey goods may be the same as that applied to the other face of the grey goods. Preferably, the patterns are different but compatible. Printing the pattern on the grey goods facilitates the printing of a plurality of colors simultaneously with higher speeds of production and substantially lower cost for the end product. Where desired, the grey goods having a pattern printed on opposite faces thereof may be subjected to embossing rollers which emboss any one of a wide variety of surface textures to the grey goods in a manner which is compatible with the pattern applied to the opposite faces of the grey goods.

It is an object of the present invention to provide novel method for printing an ink pattern on opposite faces of a web of grey goods double knit from a synthetic material.

It is another object of the present invention to apply multicolor patterns by printing the same on opposite faces of double knit grey goods.

It is another object of the present invention to provide a method for applying patterns to grey goods in a manner which does not involve the use of dyes and thereby avoid ecology objections to prior art relating to application of color and/or patterns to grey goods.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there is shown in the drawing a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentality shown.

FIG. 1 is a diagrammatic elevation view of apparatus in accordance with the present invention.

FIG. 2 is a partial plan view of a web of paper having an ink pattern to be applied to one face of the web of fabric.

FIG. 3 is a partial plan view of a web of fabric having an ink pattern applied to one face thereof.

FIG. 4 is a partial plan view of the fabric shown in FIG. 3 but showing a pattern applied to an opposite face thereof.

Referring to the drawing, where like numerals indicate like elements, there is shown in FIG. 1 apparatus in accordance with the present invention designated generally as 10. The apparatus 10 has associated therewith a source of fabric 12. The source of fabric 12 may be a wheelcart, receptacle, or spool of wound grey goods.

The grey goods is in the form of a web of fabric 14 double knit from a synthetic material such as a polyester, amides, acrylic, etc., goods. The web of fabric 14 is free from any oil which may have been added to the filaments to facilitate ease of knitting. Any such oil has been removed by scouring. Also, the web of fabric 14 has been heat set. One suitable way in which fabric double knit from synthetic material may be heat set is to continuously pass the web of fabric through a gas fired oven at a temperature of about 320.degree.F., when the synthetic materials is a polyester, for a period of about 7 seconds to stabilize the polyester filaments from which the web of fabric was knitted. The heat setting temperature and dwell time may vary as the specific fabric changes.

The web of fabric 14, in the form of grey goods double knit from synthetic material, extends upwardly around an idler roller 18 and may pass through a tension bar 16. From the idler roller 18, the web of fabric 14 extends downwardly through a guide 20 and around idler rollers 22 at a first printing station. Thereafter, the web of fabric 14 extends arouond a heated cylinder 24 and is held taut. The cylinder 24 is supported by drive shaft 16 for rotation in the direction of the arrow thereon as shown in FIG. 1.

The cylinder 24 is driven at a speed so that a portion of the web of fabric 14 will be juxtaposed to the periphery of cylinder 24 with a dwell time of about 20 seconds. The cylinder 24 is heated in any conventional manner to a temperature of about 400.degree. to 480.degree.F. When the synthetic material used to knit the web of fabric 14 is a polyester, the temperature of cylinder 24 is preferably 450.degree.F.

An endless belt 28 extends around idler rollers 30 and the cylinder 24 with the web of fabric 14 disposed therebetween. The belt 28 is made from any convenient material which will not be harmed by temperature to which it will be subjected during operation of the apparatus 10. Any one of the idler rollers 30 may be adjustably supported so as to tension the belt 28 to apply pressure on the web of fabric 14 in an amount which is about 1 psi of the effective zone juxtaposed to cylinder 24. As shown such zone is about 180.degree.-200.degree.. The amount of wrap and hence dwell time may be varied by moving the lower idler rollers 30.

A source of paper 32 is provided. The source of paper 32 is preferably in the form of a roll of paper mounted on a tensioned unwind shaft 34. The source of paper 32 thus includes a web of paper 36 having a single color or multicolor pattern 38 on a face thereof which will be juxtaposed to a face of the web of fabric 14. The web of fabric 14 is slightly less than the width of the web of paper 36 by a suitable dimension such as one-half inch. The web of paper 36 with the pattern 38 on its uppermost surface is fed between the web of fabric 14 and the peripheral surface of cylinder 24 and then is wound up on a winder designated generally as 40. The winder 40 is preferably of the constant torque type which will maintain the web of paper 36 taut and will provide slippage if too much torque is utilized to wind up the web of paper 36.

It will be noted that the web of fabric 14 is at all times above the web of paper 36. The face of the web of paper 36 which does not contain the pattern 38 is juxtaposed to and in contact with the rotating periphery of cylinder 24. The web of fabric 14 is between the web of paper 36 and the belt 28. While the taut webs 14 and 36 are pulled at the same speed and are subjected to heat and pressure, the pattern 38 on the web of paper 36 is printed onto the web of fabric 14. The web of paper 36 may be a 45 pound kraft paper covered on both sides with clay and sold commercially by the Oxford Paper Company of Rumford, Maine. The ink used to delineate the pattern 38 is preferably a subliming ink which will be printed on the web of fabric 14 due to sublimation. Sublimation is a process whereby any product undergoes a transfer from a solid to a gaseous state without passing through an intervening liquid state. Per se, subliming inks are known to those skilled in the art. The pattern 38 is preferably applied to the web of paper 36 by a rotogravure printing of a subliming ink having high energy dye color substances called dyestuffs.

In addition to applying the pattern 38 to the web of fabric 14, the web of paper 36 may also apply a color which forms the background for the pattern 38 whereby grey goods will attain the apperance of a white background color, for example. As will be apparent from FIG. 2, the pattern 38 is preferably in the form of discrete ink markings which simulate threads used when knitting or weaving colored filaments to attain a particular pattern. The opposite faces of the web of fabric 14 are designated 15 and 17. The pattern 38 on the web of paper 36 is transferred to the primary face 15 of the web of fabric 14 to produce the pattern 38'.

From the lowermost idler roller associated with the belt 28, the web of fabric 14 extends upwardly across a conveyor 42 so that the web of fabric 14 moves in a direction opposite to the previous direction of movement. The conveyor 42 includes a plurality of idler rollers 46 and a drive roller 48 around which extends an endless belt 44. From the conveyor 42, the web of fabric 14 extends downwardly through a guide 50 to a second printing station. The web of fabric 14 extends around idler rollers 52 and then around a second heated cylinder 54 mounted on a drive shaft 56. Cylinder 54 is identical with cylinder 24. The web of fabric 14 is pressed toward the cylinder 54 by an endless belt 58. Belt 58 extends around idler rollers 60. Any one of the idler rollers 60 may be made adjustable for tensioning the belt 58 to apply a similar pressure as described heretofore. The dwell time of the web of fabric 14 with respect to cylinder 54 is the same as that described heretofore. It will be noted that the face 15 of the web 14 is juxtaposed to the belt 58.

A source of paper 62 such as in a roll containing a web of paper 66 is supported by an unwind shaft 64 which is tensioned in the same manner as shaft 34. The web of paper 66 extends around the cylinder 54 and then extends to a winder 68. The face of the web of paper 66 remote from the surface of cylinder 54 contains a pattern comparable to pattern 38 which is juxtaposed to the surface 17 of the web of fabric 14. Due to the appliction of heat and pressure at the heretofore mentioned dwell time, the pattern on web of paper 66 is printed onto the face 17 of the web of paper 14 and designated as 67 in FIG. 4. The pattern 67 is compatible with the pattern 38' and may be of the same or matching colors and preferably has the same background color. Since the subliming ink printed on the face 15 to form the pattern 38' sets in about one second, the pattern 38' is not disturbed due to contact with the belt 58.

From the cylinder 54, the web of fabric 14 extends upwardly between an embossing roller 70 and its mating anvil 72. The embossing roller 70 and its anvil 72 are adapted to be separated from one another so that the web of fabric 14 may pass therebetween without getting embossed when desired. At all times, the embossing roller 70 and its anvil 72 are geared together without any backlash so as to remain in synchronization.

The embossing roller 70 embosses the primary face of the web of fabric 14, namely the face 15 containing the pattern 38'. The configuration of the embossments applied by the roller 70 may be chevrons, a dimpled pattern, parallel lines etc. Different embossing rollers with mating anvils may be substituted for one another as desired. The anvil 72 preferably has a plastic sleeve on its outer periphery.

From the embossing roller 70, the web of fabric 14 extends upwardly around drive roller 74 and 76. Thereafter, the web of fabric 14 extends downwardly through a horizontally reciprocal folder 78 which feeds the web of fabric 14 to a receiver 80 such as a wheeled receptacle. Thereafter, the web of fabric 14 may be subjected to one or more finishing operations such as a steaming frame wherein live steam is applied to soften and improve the hand of the fabric.

Separate AC or DC drives are provided for the various driven components of the apparatus 10. The separate drives are preferably variable speed range drives whereby the web of fabric 14 will be moved at a rate of about 6 to 10 yards a minute depending upon the weight of the material which may range between 6 and 14 ounces per square yard and the type of material. The webs of paper wound on the winders 40 and 68 are expandable and discarded after a single use.

The winder 40 causes the web of paper 36 to be unwound and moved into frictional contact with the cylinder 24. The winder 68 causes the web of paper 66 to be unwound and moved into frictional contact with the cylinder 54. The web of fabric 14 is moved by means of frictional contact with the belt 28, by the conveyor 42, by frictional contact with the belt 58, by the pulling effect of the embossing roller 70, and by the driven rollers 74, 76.

It will be noted that the printing of the opposite faces of the web of fabric 14 is accomplished sequentially while the web of fabric 14 is moved continuously and reverses its direction of movement whereby minimal floor space is utilized and minimum apparatus is needed to facilitate the printing of compatible patterns on opposite faces of the web of fabric 14.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and, accordingly, reference should be made to the appended claims, rather than to the foregoing sepcification as indicating the scope of the invention.

Claims

I claim:

1. A method of printing a fabric comprising the steps of providing a web of double knit heat-set fabric which is substantially oil free gray goods having a weight of between 6 and 14 ounces per yard, feeding said web of fabric, providing a web of paper having a subliming ink pattern and background color thereon, feeding said web of paper so that the webs are in frictional contact with one another, transfer printing said ink pattern and background color from the web of paper to one face of said web of fabric while the moving webs are taut and subjected to heat and pressure at a first printing station, providing a second web of paper having subliming ink pattern and background color thereon, feeding said second web of paper so as to be juxtaposed to the opposite face of the web of fabric, transfer printing the ink pattern and background color on said second web of paper to said opposite face of said web of fabric while the web of fabric and second web of paper are taut and subjected to heat and pressure at a second printing station, and then collecting the web of fabric which has been printed on opposite faces thereof at a receiver.

2. A method in accordance with claim 1 wherein said step of printing the pattern from said second web of paper to said opposite face of said web of fabric includes orientating the pattern on said opposite face with respect to the pattern on said one face of the web of fabric.

3. A method in accordance with claim 2 wherein said step of transfer printing a pattern to said web of fabric includes the use of ink markings which simulate woven threads.

4. A method in accordance with claim 1 wherein said webs of paper are below said web of fabric so that the transfer printing is in an upward direction, and reversing the direction of the movement of said web of fabric as it moves between the printing stations.

5. A method in accordance with claim 4 wherein said fabric is a synthetic material selected from a group consisting of polyesters, acrylics, and amides.

6. A method in accordance with claim 1 wherein the pressure between the web of fabric and the webs of paper is approximately 1 pound per square inch and the temperature at said stations is approximately 400.degree. to 480.degree.F.

7. A method in accordance with claim 1 including embossing the pattern on said one face of the web of fabric after both faces of the web of fabric have been printed.