Embossing And Valley Printing Of Carpets By Hot Melt Ink

Abstract

A deep engraved embossing roll has applied thereto hot melt inks. The roll embosses a fiber carpet with the hot melt ink providing a color decoration in the valley areas and at the same time sealing the embossed fibers in place.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention is directed to a method of embossing carpet and, more particularly, to an embossing and coloring of the valley areas of the embossed carpet.

2. Description of the Prior Art

U.S. Pat. No. 1,642,505 discloses a short-haired or smooth-haired skin which has been embossed and colored to provide markings which simulate expensive animal skin. In the above patent, the ink is merely used for coloring and the embossing provides a marking of the skin.

U.S. Pat. No. 3,230,106 discloses the use of hot wax inks being used to provide markings on paper. There is no indication that an embossing function is carried out.

U.S. Pat. No. 2,314,162 shows the use of paraffin wax being made an integral part of a fibrous material which is later subjected to embossing, anad the paraffin wax within the article tends to hold the embossed fabrics in their embossed position. Any coloring is secured by another means, and the paraffin is not incorporated into a separately applied material which is applied at the time of embossing.

It is the principal object herein to provide a technique wherein the ink performs both a coloring function and a fabric-holding function when the fabric has been embossed.

SUMMARY OF THE INVENTION

The process involves an embossing roller equipped with an engraved surface which has been engraved to a depth at least 1/4 inch. This deep engraving is necessary in order to keep from bottoming out and affecting the face fibers or unembossed fibers. A valley printing head is used to apply hot melt ink to the embossing roll or intermediate transfer rolls. The heated embossing roll coming in contact with the carpet embosses the carpet and in turn transfers the hot melt into the valleys. The hot melt pentrates the fibers at the point of contact and, upon cooling, holds the fibers in place and at the same time offers color decoration.

BRIEF DESCRIPTION OF THE DRAWING

The drawing is a schematic layout of the ink-applying and roll-embossing structures.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing, a natural or synthetic fiber carpet 2 is fed between a lower steel impression roll 4 which functions as a back-up roll for the heated steel embossing roll 6. The heated steel embossing roll has a plurality of raised areas 8 which are used to form the valley areas 10 of the embossed carpet. Normally, the embossing roll will be engraved to a depth of at least 1/4 inch. This deep engraving is necessary in order to keep the unembossed areas 11 of the carpet from bottoming out or engaging the depressed areas 9 of the embossing roll. Should this bottoming out occur and the fibers of the raised area 11 be engaged by the depressed areas 9 of the embossing roll, the roll could partially emboss or in some other way affect the fiber faces in the areas 11. The roller is heated primarily to keep the wax in a softened state. The temperature to which the roll is heated is dependent upon both the heat needed for maintaining the hot melt wax in its softened state and the heat which is sufficiently low so that it will not affect the fibers being embossed. In carrying out the invention on a piece of polypropylene carpet material, the embossing roll was maintained at a temperature of 250.degree. F.

A three-roll valley printing head is used to apply the hot melt ink. The ink is maintained initially in a heated tank 12. The ink then flows by gravity to a heated trough 14 from which it is picked up by a heated silicon rubber roll 16. The use of a silicon rubber roll provides good ink transfer as well as offering good heat stability. The ink is transferred from roll 16 to heated steel roll 18 and then to a second heated silicon rubber roll 20. The heating of the rolls is necessary to keep the hot melt ink softened to a flowable state. The transfer from roller to roller provides for the volumetric transfer of the ink to roll 20 so that it is in a proper softened state, is uniformly distributed across the roll 20 and capable of transfer to the embossing roll so that the embossing roll will be properly covered in its raised areas with the required amount of hot melt ink for the subsequent embossing operation.

The heated embossed roll 6 receives the hot melt ink on its raised areas 8 and not in the depressed areas 9. The heated embossing roll comes in contact with the carpet and embosses the carpet to form the depressed areas 10 in the carpet. The hot melt ink is transferred from the raised areas 8 of the embossing roll to the depressed areas 10 of the carpet during the embossing process. The hot melt penetrates the fibers at the point of contact and, upon cooling, holds the fibers in place and at the same time this hot melt ink offers a color decoration in the depressed areas 10. The mechanical embossing sufficiently depresses the fibers, and the fibers are sufficiently slow in returning to their normal position that the hot melt ink has sufficient time to cool and hold the fibers in their depressed state.

The above method was carried out using a hot melt ink having the following formulation:

Percent by Weight Piccolyte (terpene polymer) 25% Elvax 210 (vinyl-acetate resin) 15% Ozokerite 195 (mined wax - melt 30% temperature 180.degree. F.) Multiwax ML-445 (mined wax - melt 29% temperature 145.degree. F.) Pigment 1%

Other conventional hot melt inks could also be used since several are available commercially.

This particular ink was heated to 225.degree. F. in the heated tank and maintained by the heated trough and heated silicon rubber and steel rolls and embossing rolls to a temperature of substantially 225.degree. F. so that it was in a sufficiently flowable state at the point of embossing to transfer to the fibers of the carpet material and cool with a sufficient degree of rapidity to hold the fibers in place.

Claims

I claim:

1. The method of embossing and valley printing a carpet which is provided with a plurality of raised fibers capable of being embossed to such a degree as to form depressed areas, the steps comprising; heating a hot melt ink to a flowable state, transferring the ink from a heated reservoir through appropriate transfer structure to a heated embossing roll, applying the hot melt ink to only the raised areas of the heated embossing roll, then passing the carpet under the embossing roll to emboss the carpet with a plurality of depressed areas, said depressed areas being formed by the hot melt coated raised areas of the embossing roll, simultaneously with the embossing, transferring the hot melt ink to the depressed areas of the carpet, and cooling the ink to both hold the embossed carpet fibers in place and at the same time provide a color decoration to the embossed areas of the carpet.