GB2142352A - Embossing fabrics - Google Patents

Abstract

A method of embossing a fabric containing keratinous fibres, particularly lambswool or botany knitwear, in which a stabilising agent, for example a shrink resist resin, for the keratinous fibres is applied by exhaustion followed by embossing the material. The embossing is carried out on a hosiery press using a template to produce the required pattern. After the embossing step the stabilising agent is cured. The stabilising agent is preferably an organothiosulphate or a polycarbamoyle sulphonate. The embossing step may be carried out in a wet or dry state but if carried out in the dry state it is preferred to apply some reducing agent to the fabric after the application of stabilising agent.

Description

SPECIFICATION Treating of textiles This invention relates to a method of treating textiles and in particular relates to a method of embossing fabrics containing keratinous fibres.

Various processes are known for the embossing of fabrics. However, most of these processes have one or more disadvantages particularly when applied to fabrics which are to be used for clothing, or to ready made garments. For example the embossing process may leave the fabric with a harsh handle, or may not be stable to machine washing.

It has been proposed to print fabric in a predetermined area with a composition comprising a stabilising agent for the keratinous fibres and a thickening agent, thereafter drying and embossing the printed fabric, and washing the material to remove thickening agent. While this process gives very good results, it is necessary to use printing techniques and to wash excess thickening agent from the fabric after use.

The invention seeks to provide an embossingprocess suitable for keratinous textile fabrics and garments in which the above disadvantages are reduced or overcome.

According to the present invention there is provided a method of embossing a fabric containing keratinous fibres in which a stabilising agent for the keratinous fibres is applied by exhaustion, the material is embossed, and the stabilising agent cured. The process can be applied to fabrics containing a variety of keratinous fibres, for example alpaca, vicuna, mohair, angora, and especially wool. The process may be applied to fabrics or garments entirely or substantially made from keratinous fibres, preferably lambswool or botany wool.

The fabric can be woven, non woven or knitted, although the invention is particularly applicable to knitted fabrics and especially knitwear.

The stabilising agents are selected from curable resins which impart to the keratinous fibres a resistence to shrinking when fabric formed from them are washed, particularly in a domestic washing machine. Examples of such resins are polyacrylates, polyethylene imines, condensation products of polyamides with epichlorhydrin, organothiosulphates particularly those described in our UK Patents 1423342 and 1423341 available under the trade name LANKROLAN SHR3, (DIAMOND SHAMROCK LTD). silicones, and polycarbamoyle sulphonates in particular those described in UK Patent 1419306 and available under the trade name SYNTHAPPRET BAP.

(BAYER AG).

The stabilising agents are preferably applied in the form of aqueous solutions or emulsions and are applied by an exhaustion process from long liquors.

The quality of the embossing can in certain cases be improved cons iderably if, prior to the exhaustion step, the fabric or yarns or fibres comprising the fabric are treated with chlorine. A convenient procedure is to treat the premade garment with a chlorinating agent, for example, sodium hyprochlorite or preferably an alkaline metal salt of dichlorocyanuric acid such as those available under the trade names BASOLAN (BASF) or FICLOR CLEARON (CHLOR-CHEM LTD). After treatment with the chlorinating agent the material may require treatment with a dilute solution of a base or an alkaline metal sulphite to remove any excess chlorine.

Knitted fabrics prior to treatment may also be subjected to certain routine treatments associated with wet finishing of keratinous fibres. For example, fabrics knitted from woollen spun yarns should be scoured and milled, whilst fabrics knitted from worsted spun yarns should be subject to an anti-cockling treatment and then scoured. Various method can be used for the anticockling step, for example treating the material in a boiling bath containing a reducing agent, for example sodium bisulphite, possibly together with a surface active agent. Scouring can be carried out conveniently by heating the material in a bath containing a surface active agent, such as the product sold under the trade name NONIDET SH30 (Shell Chemicals).

The embossing step can be carried out on a conventional Knitwear hosiery press, for example a Hoffmann press, but where made up garments are being embossed it is preferred to use a type of press in which a raised buck is supported preferably at one end only so that the garment may be pulled over the buck so that the back face of the garment being treated is not subjected to pressing during the embossing step. A head pressure of about 5 bars may be used and temperatures in the region of 100 to 105"C have generally been found satisfactory. The embossing step is preferably carried out with the use of steam, and a typical cycle would involve steaming for 15 to 30 seconds followed by baking for 1 5 to 30 seconds.It is important to heat the die or template to be used for embossing to its working temperature prior to the introduction of the material to be embossed. The material to be embossed can be wet or dry, but it is generally preferred that it should be dry in order to obtain the best embossed effects and for ease of handling.

In order to ensure a satisfactory depth of embossing, a layer of heat resistant material, for example a heat resistant foam sheet, is preferably positioned on the press buck in order to obtain satisfactory depth of emboss.

The die or template used to produce the embossed pattern may be a wooden or plastics material die carved, moulded or otherwise formed into a template for the required pattern. The die or template may be fixed to the press head or manually located on to the garment face.

If, for processing reasons, it is desired to emboss the fabric in a dry state, then it is preferred to include some reducing agent, for example sodium sulphite, in the fabric after the resin exhaustion treatment. It has been found that embossing dry fabrics treated with a reducing agent after the resin treatment improves the stability of the embossed effect.

The invention will be illustrated by reference to the following examples.

EXAMPLE 1.

A garment made from 2/16's worsted count lambswool woollen yarn (yarn dyed), knitted to a cover factor of 0.95 (in-1 WcL1/2) was scoured and milled as follows. Scouring was carried out in a side paddle machine using 3 g/litre of NONIDET SH30 (Shell), 2.2 g/litre of anhydrous sodium sulphate, and 1 % (oww) of sodium bicarbonate. Scouring was carried out for 10 minutes at 40"C.

The fabric was then milled in a rotary washing machine in a liquor containing 0.75 g/litre of LEVNITE (Stephensons Ltd.) until the desired finish was obtained after which it was rinsed for 10 minutes at 40"C in a side paddle machine.

The scoured and milled fabric was chlorinated at a liquor to goods ratio of 30 : 1 as follows. The bath was set at pH 6 after which 3.2% (oww) of FICLOR CLEARON (Chlor Chem Limited) was added and the goods agitated for 20 minutes. The pH was adjusted to 5 and the bath run until exhausted. After which 3% (oww) sodium bisulphite was added to remove any remaining chlorine and the bath run for a further 10 minutes. The spent liquor was drained and fresh liquor was set at 40"C with 5% (oww) sodium bicarbonate and run for 1 5 minutes to neutralise the fabric after which the fabric was rinsed for 10 minutes at 40"C.

The fabric was then treated with a shrink resist resin at a liquor to goods ratio of 30 : 1 as follows. The bath was set to pH 8 at 30"C with sodium carbonate after which 8 g/litre of magnesium chloride hexahydrate was added and the goods agitated for 2 minutes. 1. 25% (oww solids) of SYNTHAPPRET BAP (Bayer) was dissolved in 10 times its own volume of water added to the treatment bath and when dispersed into the liouor 1.25% (oww solids) of IMPRANIL DLN (Bayer) also dissolved in 10 times its own volume of water, was added.

The temperature raised to 60"C over 30 minutes at a rate of 1"C per minute. At 60"C, 5 g/litre of sodium sulphite (anhydrous-predissolved) was added and the goods agitated for 2 minutes. The goods were hydroextracted and tumble dried for 20 minutes at 55"C--60"C.

Embossing was carried out by placing the garments face side up over the buck of a Hoffmann utility press with a die or template placed on top, and the press head closed. The template was thoroughly steamed prior to use to avoid condensation during the embossing operation. The press head pressure was 5 bar and the pressing cycle was 1 5 seconds steam followed by 1 5 seconds bake giving a total pressing time of 30 seconds, followed by 10 seconds of vacuum. Steam from the buck only was used. Steam valve was almost fully open to allow a copious amount of steam during the steaming cycle since if steam supply is restricted a longer cycle will be required.It is preferred to use steam supplied through the buck and head rather than the head only since it is possible that steam loss across the die or template will occur requiring a longer steaming cycle. After pressing, the garment is tumble dried during which curing takes place, for 10 minutes at 90 to 100"C.

Excess chemicals may be washed off which also improves the fabric appearance and handle for 10 minutes at 40"C after which the fabric is hydroextracted and tumble dried.

The garment so treated was found to have a pleasant embossed effect, good handle, and the embossed effect was found to be durable to machine washing.

EXAMPLE 2.

A garment made from 2/24's worsted count botany yarn knitted to a cover factor of 1.15 (in-' wc-1,2 was treated as follows.

The garment was first given an anti-cockle treatment with 3% (oww) sodium bisulphite at 1 00'C. The garment was agitated for 3 minutes and allowed to stand for 1 5 minutes. A fresh bath at 40"C was made up having 1 g/litre of NONIDET SH30, 2.2 g/litre of anhydrous sodium sulphate and 1% (oww) sodium bicarbonate in which the garment was scoured for 10 minutes. After this the garment was rinsed for 10 minutes at 40"C.

The chlorination was carried out as in Example 1 except that 3. 8% (oww) FICLOR CLEARON was employed. The resin exhaustion was carried out as in Example 1 except that 0.75% (oww solids) SYNTHAPPRET BAP and 0.75% (oww solids) INPRANIL DLN was employed and also using a sodium sulphite (anhydrous) concentration of 0.75 g/litre. The embossing step was carried out as in Example 1.

Again a pleasing embossed effect was produced without affecting the soft handle of the garment and the embossed effect was durable to machine washing.

If any creasing is apparent after rinsing in sulphite and hydro-extraction then lower concentrations of sodium sulphite should be used. It is recommended to use no lower than 0. 3 g/litre and 2.5 g/litre sodium sulphite (anhydrous) for the worsted and woollen sub strates respectively.

EXAMPLES 3 s 4.

Examples 1 and 2 were repeated omitting the addition of sodium sulphite after the resin exhaustion step and omitting the tumble drying step after resin exhaustion and hydroextraction leaving the goods with approximately 40% (oww) water retention when the embossing step was carried out. In both cases excellent results were obtained.

The above treatments are also applicable to garment panels except that the pressing step is more conveniently carried out on a hosiery steam press.

The embossing template should be thin and flexible so that it may be used with pressing heads and bucks which have curved surfaces, and also should be durable and resistent to compression. Preferably the embossing template is drilled with small holes to help the passage of steam.

If the resin exhaustion step is controlled at pH 8 only a minimal curing of resin occurs during the drying step prior to embossing.

Partial curing of resin occurs during pressing and full curing takes place in the tumble drying step after embossing thereby stabilising the embossed effect. If exhaustion pH conditions are slightly acid, for example pH 6 or lower, it is preferable to rinse the goods at pH 8 before embossing in a solution containing 8 g/litre magnesium chloride hexahydrate.

The drying step, if employed, after resin exhaustion should not exceed a temperature of 55-60' in order to prevent curing of resin during that step since if curing to a substantial extent does take place during that step the embossed effects are less substantive to washing.

The fabric or garment treated, particularly if knitted, should be of a fairly tight construction for best results. Thus lambswool and botany garments may usually be employed without difficulty, but shetland knitted garments are not always suitable.

Where the chlorination step prior to the resin exhaustion step is omitted excellent results can still be obtained, but the durability to machine washing may not be sufficient and it is therefore recommended that the garments treated according to this route only be hand washed.

Claims (14)

1. A method of embossing a fabric containing keratinous fibres in which a stabilising agent for the keratinous fibres is applied by exhaustion, the material is embossed, and the stabilising agent cured.

2. A method as claimed in claim 1 applied to fabrics or garments entirely or substantially made from lambswool or botany wool.

3. A method as claimed in either of claims 1 or 2 in which the fabric is is a knitted fabric.

4. A method as claimed in any of claims 1 to 3 in which the stabilising agent is a curable resin which imparts to the keratinous fibres a resistance to shrinking.

5. A method as claimed in any of claims 1 to 4 in which the stabilising agent is an organothiosulphate or a polycarbamoyle sulphonate.

6. A method as claimed in claim 5 in which the stabilising agents are applied in the form of aqueous solutions or emulsions by exhaustion from long liquors.

7. A method as claimed in any one of claims 1 to 6 in which the fibres are treated with chlorine prior to the application of stabilising agent.

8. A method as claimed in any one of claims 1 to 7 in which the embossing step is carried out on a knitwear hosiery press employing a template to produce the embossed effect.

9. A method as claimed in claim 8 in which the press has a raised buck supported at one end only so that a garment may be pulled over the buck allowing one face only to be subjected to pressing during the embossing step.

10. A method as claimed in any one of claims 1 to 8 in which a die or template is employed to produce the embossed pattern.

11. A method as claimed in claim 10 in which the template is a wooden or plastics material die carved moulded or othermise formed into the required pattern.

1 2. A method as claimed in any one of claims 1 to 11 in which the embossing step is carried out with the fabric in either wet or dry state.

1 3. A method as claimed in any one of claims 1 to 1 2 in which the embossing step is carried out with the fabric in a dry state, and further including the step of applying a reducing agent to the fabric after the application of the stabilising agent.

14. A method of embossing a fabric containing keratinous fibres substantially as hereinbefore described with reference to and as illustrated in the foregoing examples.