GB1583953A

GB1583953A - Transfer printing of textile material

Info

Publication number: GB1583953A
Application number: GB3156576A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-07-01
Filing date: 1977-07-01
Publication date: 1981-02-04

Description

(54) IMPROVEMENTS RELATING TO THE TRANSFER PRINTING OF TEXTILE MATERIAL (71) I, RICHARD DONOVAN GLOVER, a British Subject, of R.G.S. Pattern Book Company Limited, of Godham Mills, Ossett, Yorkshire, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be described in and by the following statement This invention relates to the transfer printing of textile materials.

In the transfer printing of textile materials, such as yarns, slivers, carded webs, woven, non-woven and knitted fabrics, pile fabrics, it is usual to apply heat to the textile material when it carries or is in contact with the colouration dyestuff.

In the transfer printing process, the heat may be applied by infra-red heating means, electric heaters or a heated platen or cylinder which contacts the textile material or is arranged in close proximity thereto to effect the heating. Also in the transfer printing process, the known methods of heating the sheet structure suffer from the disadvantage that the heat is applied directly to the surface of the sheet structure, and there tends to be a temperature gradient across the thickness of the sheet structure during the heating thereof.

This temperature gradient is larger, the larger the thickness of the sheet structure, and certainly is significant when the sheet structure is a pile fabric such as a carpet, rug or carpet tile. When transfer printing these pile fabrics, it is desirable that the heating thereof should be as even as possible across the thickness of the pile, because the dyestuff is usually applied in a thin layer and it is desireable that in the heating process the dyestuff will penetrate the pile as much as possible, in order to give even colouration throughout the pile thickness.

The present invention aims at providing a method for the transfer printing, in particular of pile fabrics, using sublimable dyestuff, but as will be appreciated hereinafter, it can be used for other textile materials, wherein the heating across the pile during the colouration is more even than heretofore.

In accordance with the present invention, a textile material is transfer printed and is heated by means of microwave energy when the dyestuff is in contact therewith.

It is known that microwave energy can be used for heating and that the microwaves are attenuated upon meeting the object or article to be heated, by being absorbed by the moisture of, or in, or carried by the article or object. If, therefore, the textile material being transfer printed in accordance with the present invention contains no moisture, then it will require to be dampened before heating by the microwave energy. Where the material is a sheet structure, it may be a finite sized article such as a carpet tile or rug, in which case the heating could take place in a microwave oven, or it may be a continuous web, in which case the heating by microwave energy could take place in a waveguide, split to allow the passage of the web therethrough.

As the process is a transfer printing process using sublimable dyestuff, the sheet structure will be of, or include a textile which has an affinity for the dyestuff, and the heating by microwaves may take place whilst a carrier sheet, having the dyestuff printed thereon in conventional manner, is in contact with the textile sheet structure, or after the textile sheet structure has been transfer printed and the carrier removed.

The invention provides that when a pile fabric is being heated, it will be heated more evenly throughout its thickness, certainly quicker than is the case when using conventional heating methods for transfer printing. This ensures that the bottom of the pile can quickly be heated to the same temperature as the top, and any intermediate point in the thickness of the pile. This even heating assists more even colouration of the pile throughout the thickness thereof.

The method can be applied in cases where the colouration dyestuff has been applied to the sheet structure or to a backing sheet thereof prior to the heating by microwave energy, and can also be used in conjunction with a means for assisting the dyestuff to flow through the thickness of the sheet structure to improve the dyestuff penetration, for example, as set forth in British Patent No. 1,376,108 or co-pending Applications Nos. 39062/75 (Serial No. 1,565,047) and 41684/75 (Serial No. 1,567,901) and 41685/75 (Serial No. 1,566,705).

The invention also provides a textile material transfer printed by the method herein set forth.

The selection of the dyestuff type for any particular textile material is well known in the art.

The microwave heating can be used alone or in combination with other forms of heating provided such other heating means does not interfere with or prevent the heating by microwave energy.

An embodiment of the invention, and a number of modifications thereOf, will now be described by way of example, with reference to the accompanying drawings, of which the single figure illustrates the embodiment of the invention in diagrammatic form.

Referring to the drawing, 10 represents a split micro-wave heating chamber supplied with microwave energy from a microwave energy generator 12 of conventional form. A pump means 14 serves to pressurise the top portion of the chamber 10, whilst a suction pump 16 serves to vacate the lower portion of the chamber 10. The top of the lower portion may be closed by means of a grid 18 in order to support textile material 20 which is passed along the slit in the chamber 10 and through said chamber so as to be heated by the microwave energy generated from generator 12 and passed to chamber 10.

In the example shown, a supply roll 22 of the textile material is shown and there is also shown a take-up roll 24 of such matefial. It is to be pointed out that the example illustrated envisages the flse of a web of textile material such as a fabric or a carpet, but equally it could be a thick sliver of textile material, or a band of parallel yarns, or even loose fibrous material.

If it is assumed that the web 20 is a pile carpet (with Or without a backing material) the pile is printed from a transfer printed carrier sheet 26 which progressively is unwound from a supply roll 28 to a take-up roll 30, travelling around two guide rolls 32 and 34. As the carrier passes between rolls 32 and 34 which also act as pressure rolls, it is pressed against and moves with the web 20.

A heating means 36 located between the rolls 32 and 34 serves to heat the sandwich of carrier sheet and pile fabric so as to cause an initial transfer of the sublimatic dyestuff from the carrier sheet to the fabric 20. The heating means 36 is illustrated as being of conventional form, but it may also be a microwave heating means similar to the means 10 and 12 illustrated.

After being thus initially printed, the web 20 passes into the microwave heating cham ber 10 wherein the dyestuff is permanently fixed under the heating influence of the micro waves from generator 12, and additionally, either pump or fan 14 and pump 16, or both, is or are operated so to cause an airflow from the top to the bottom of chamber 10 and through the pile fabric 20 whilst it is being heated by the microwave energy. This is to convey into the pile of the fabric any dye stuff which sublimes and becomes airborne as a result of the heating by the microwave energy.Thus, if there is a heavy concentration of dyestuff on the tips of the tufts con stituting the pile, while at the top of the pile, the heating by microwave energy will release dyestuff particles which will be carried down into the pile and deposited at a greater depth into the pile as a result of the air flow through the pile which is established during the heating. The effect of this is to give a more even dyeing of the fabric throughout the height of the pile. In the case where the textile material is a fabric or a bank of parallel yarns, the air-flow also has the effect of trans ferring dye to the unprinted side of the fabric or bank to ensure ad even printed appearance from both sides of the fabric. Finally, the printed web 20 as it emerges from the heating chamber 10 is wound on take-up roll 24.

It is possible to operate the process by arranging for roller 24 and roller 30 to be located on the opposite side of the heating chamber 10, and for the heating means 36 to be omitted. In this case, the entire heating is effected by means of the microwave energy generated by generator 12, although in this embodiment it is desireable if the air flow through the fabric is to be established, to use a carrier sheet which is of sufficient porosity to allow the flow of air therethrough.

It is believed that the natural moisture in the textile materials will be sufficient to absorb the microwave energy generated by generator 12 to raise the temperature of the material to the required value, but if necessary the material may be pre-dampened in order to ensure that there is sufficient heat gene rated.

WHAT I CLAIM IS:- 1. A method of transfer printing a textile material by the application of heat and dyestuff thereto, the heating being by or including heating by means of microwave energy when the dyestuff contacts the textile material.

2. A method according to Claim 1, wherein the textile material is in web form, and passes through a split microwave heating chamber.

3. A method according to Claim 2, wherein there is established a flow of air through the textile material whilst it is being

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Claims

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flow through the thickness of the sheet structure to improve the dyestuff penetration, for example, as set forth in British Patent No. 1,376,108 or co-pending Applications Nos. 39062/75 (Serial No. 1,565,047) and 41684/75 (Serial No. 1,567,901) and 41685/75 (Serial No. 1,566,705).

The invention also provides a textile material transfer printed by the method herein set forth.

The selection of the dyestuff type for any particular textile material is well known in the art.

The microwave heating can be used alone or in combination with other forms of heating provided such other heating means does not interfere with or prevent the heating by microwave energy.

An embodiment of the invention, and a number of modifications thereOf, will now be described by way of example, with reference to the accompanying drawings, of which the single figure illustrates the embodiment of the invention in diagrammatic form.

Referring to the drawing, 10 represents a split micro-wave heating chamber supplied with microwave energy from a microwave energy generator 12 of conventional form. A pump means 14 serves to pressurise the top portion of the chamber 10, whilst a suction pump 16 serves to vacate the lower portion of the chamber 10. The top of the lower portion may be closed by means of a grid 18 in order to support textile material 20 which is passed along the slit in the chamber 10 and through said chamber so as to be heated by the microwave energy generated from generator 12 and passed to chamber 10.

In the example shown, a supply roll 22 of the textile material is shown and there is also shown a take-up roll 24 of such matefial. It is to be pointed out that the example illustrated envisages the flse of a web of textile material such as a fabric or a carpet, but equally it could be a thick sliver of textile material, or a band of parallel yarns, or even loose fibrous material.

If it is assumed that the web 20 is a pile carpet (with Or without a backing material) the pile is printed from a transfer printed carrier sheet 26 which progressively is unwound from a supply roll 28 to a take-up roll 30, travelling around two guide rolls 32 and 34. As the carrier passes between rolls 32 and 34 which also act as pressure rolls, it is pressed against and moves with the web 20.

A heating means 36 located between the rolls 32 and 34 serves to heat the sandwich of carrier sheet and pile fabric so as to cause an initial transfer of the sublimatic dyestuff from the carrier sheet to the fabric 20. The heating means 36 is illustrated as being of conventional form, but it may also be a microwave heating means similar to the means 10 and 12 illustrated.

After being thus initially printed, the web

20 passes into the microwave heating cham ber 10 wherein the dyestuff is permanently fixed under the heating influence of the micro waves from generator 12, and additionally, either pump or fan 14 and pump 16, or both, is or are operated so to cause an airflow from the top to the bottom of chamber 10 and through the pile fabric 20 whilst it is being heated by the microwave energy. This is to convey into the pile of the fabric any dye stuff which sublimes and becomes airborne as a result of the heating by the microwave energy.Thus, if there is a heavy concentration of dyestuff on the tips of the tufts con stituting the pile, while at the top of the pile, the heating by microwave energy will release dyestuff particles which will be carried down into the pile and deposited at a greater depth into the pile as a result of the air flow through the pile which is established during the heating. The effect of this is to give a more even dyeing of the fabric throughout the height of the pile. In the case where the textile material is a fabric or a bank of parallel yarns, the air-flow also has the effect of trans ferring dye to the unprinted side of the fabric or bank to ensure ad even printed appearance from both sides of the fabric. Finally, the printed web 20 as it emerges from the heating chamber 10 is wound on take-up roll 24.

It is possible to operate the process by arranging for roller 24 and roller 30 to be located on the opposite side of the heating chamber 10, and for the heating means 36 to be omitted. In this case, the entire heating is effected by means of the microwave energy generated by generator 12, although in this embodiment it is desireable if the air flow through the fabric is to be established, to use a carrier sheet which is of sufficient porosity to allow the flow of air therethrough.

It is believed that the natural moisture in the textile materials will be sufficient to absorb the microwave energy generated by generator 12 to raise the temperature of the material to the required value, but if necessary the material may be pre-dampened in order to ensure that there is sufficient heat gene rated.

WHAT I CLAIM IS:- 1. A method of transfer printing a textile material by the application of heat and dyestuff thereto, the heating being by or including heating by means of microwave energy when the dyestuff contacts the textile material.
2. A method according to Claim 1, wherein the textile material is in web form, and passes through a split microwave heating chamber.
3. A method according to Claim 2, wherein there is established a flow of air through the textile material whilst it is being

heated in said microwave heating chamber.
4. A method according to Claim 1, 2 or 3, wherein a carrier sheet carrying the dyestuff and the textile material are heated whilst in contact to transfer the dyestuff to the textile material and then the textile material is subjected to the said heating by microwave energy.
5. A method according to Claim 1, 2 or 3, wherein the textile material is heated whilst a carrier sheet carrying the dyestuff and the textile material are in contact so that the microwave energy heats the textile material and effects the transfer of dyestuff from the carrier to the textile material.
6. A method of colouring textile material substantially as hereinbefore described with reference to the embodiment illustrated in the accompanying drawings, or any of the described modified versions thereof.
7. A textile material coloured by the method according to any preceding claim.