GB2108542A - Dyeing vat - Google Patents

Abstract

A paddle vat 1 wherein during the dyeing process, the dye liquor is continuously extracted from the vat 1 via an outlet 5 having a grille 6, and recirculated by means of a pump 8, which feeds the liquor back into the vat 1 via a filter 11. The filter comprises a discharge pipe 10, a mesh bag 13 around the pipe, and a perforated trough 15 supporting the bag 13. The continuous filtering removes lint from articles e.g. candlewick bedspreads, being dyed. Lint removal is enhanced by a prior dry tumbling and filtering step. <IMAGE>

Description

SPECIFICATION Dyeing This invention relates to dyeing and is concerned both with dyeing processes and dye vats. The invention is concerned particularly, although not exclusively, with the dyeing of tufted articles, such as candlewick bedspreads, for example.

Candlewich bedspreads have been popular for many years, but traditionally have one disadvantage which housewives have generally come to accept over the years. This disadvantage is the shedding of lint (i.e. fluff) and is a problem peculiar to tufted articles such as candlewick bedspreads. Due to the manufacturing process of a candlewick bedspread, there is inevitably a large number of fibres which are free to greater and lesser degrees, and which may be readily pick-up on clothes, etc., laid on a bed. A previous attempt to remedy this disadvantage consisted in the use of viscose instead of traditional cotton in a candlewick bedspread. Although the viscose tended to shed less, the feel of the article was noticably poorer, and did not find favour with the buying public.

In preferred aspects, the present invention aims to provide dyeing processes and dye vats which can be used to produce tufted articles such as candlewick bedspreads in which the problem of lint shedding is appreciably alleviated.

More generally, according to a first aspect of the present invention, there is provided a dyeing process comprising the steps of placing both dye liquor and articles to be dyed in a dye vat, extracting dye liquor from the vat, passing the extracted dye liquor through a filter, and recirculating the filtered dye liquor into the vat.

Preferably, the process includes the step of agitating the articles in the vat, for example, by the use of a paddle vat.

The process may preferably comprise the subsequent step of rinsing the articles in a rinse liquor, extracting rince liquor from the vat, passing the extracted rinse liquor through the filter, and recirculating the filtered rinse liquor into the vat.

Advantageously, the process may also include the preliminary step of tumbling the articles in a tumbling machine through which gas is passed and exhausted through a filter.

According to a second aspect of the present invention, there is provided a dye vat adapted to contain dye liquor and articles to be dyed, and comprising an outlet, a filter means, and a pump for extracting the dye liquor from said outlet and recirculating the dye liquor into the vat, through said filter means.

Preferably, the outlet comprises a duct opening into side wall of the vat, and may be provided with a grille at the mouth thereof.

In an advantageous arrangement, the filter means may be disposed at the top of the vat, and it may comprise a flexible mesh supported in a perforated hoder above the dye liquor level in the vat. The flexible mesh may be in the form of a bag, and may be of synthetic fibre material. The flexible mesh may be secured around a discharge pipe, which may be provided with at least one longitudinal slit therein.

Preferably, the dye vat is a paddle vat.

The invention also provides a method in accordance with the first aspect of the invention, when carried out with the use of a dye vat in accordance with the second aspect of the invention.

In a third aspect of the present invention there is provided a method of dyeing articles of tufted material, including the steps of tumbling the articles in a tumbling machine through which gas is passed and exhausted through a filter, and subsequently dyeing the articles in a dye vat.

Preferably, the method includes the subsequent step of drying the dyed articles in a tumble drying machine.

Preferably, the articles are dyed by a process according to the first aspect of the invention.

For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying dia grammatic drawing, the single figure of which is a sketch of a dye vat embodying the present invention, and adapted for use in carrying out a process in accordance with the invention.

The illustrated paddle vat 1 is a paddle vat adapted to contain dye liquor and articles to be dyed, and being provided with a paddle 2 which is adapted to rotate about an axle 3, to agitate articles in the vat 1.

In one side wall 4 of the vat 1 there is formed an outlet 5, provided with a grille 6 at the mouth thereof. The outlet 5 is disposed at a level just below the usual level of dye liquor in the vat 1, in use. A pipe 7 extends from the outlet 5 to a pump 8, which in turn is connected to a further pipe 9, leading to a discharge pipe 1 0.

The discharge pipe 10 has a closed end 11, and is formed with at least one longitudinal slit 1 2 therein. A flexible mesh bag 13, preferably of polypropylene fibre material or the like, is secured around the discharge pipe 10, and is closed thereabouts by means of a clip 14. The bag 1 3 is supported in a perforated trough 15, somewhat above the usual level of dye liquor in the vat 1.

An example of a vat dyeing process, using the illustrated paddle vat 1, will now be described.

The paddle 1 was filled with approximately 350 gallons of water, to which a wetting-out agent was added. The paddle 2 was then operated continuously, to agitate the liquor in the vat 1. Candlewick bedspreads to be dyed were then placed in the vat 1, and the required dye stuff was added to the water, to form the dye liquor. The temperature of the liquor was then raised to the required level, over a period of approximately twenty minutes. This temperature was then maintained for approximately thirty minutes, during which time the paddle 2 continued to operate to agitate the candlewick bedspreads in the dye liquor.

At the end of the required dyeing time, the exhausted dye liquor was drained from the vat 1, and replaced by cold clean water, in which the candlewick bedspreads were then rinsed.

After a sufficient rinsing time, the paddle 2 was stopped, and the candlewick bedspreads were pulled out of the rinse water, subjected to hydro-extraction, and then hot air tumbling.

During all the time that the candlewick bedspreads were in the vat 1, the pump 8 was operated continuously to extract dye liquor through the outlet 5, and recirculate the extracted dye liquor into the vat 1 through the discharge pipe 10 and flexible mesh bag 13, which thus served as a filter. Of course, during the rinsing cycle, it was the rinse liquor which was circulated through the bag 1 3.

As the candlewick bedspreads were agitated in the dye vat 1, the relatively loose fibre became detached therefrom and were circulated through the outlet 5, pump 8 and discharge pipe 10, and finally through the flexible mesh bag 13, where they were filtered out. The liquors were circulated through the pump 8 at a rate of about thirty gallons per minute.

After approximately 1 70 pounds dry weight of candlewick bedspreads had been in the dye vat 1 for nearly one hour, approximately two litres of wet lint residue was found in the filter bag 1 3. Bearing in mind that this lint was wet, it will readily be appreciated by those skilled in the art that this quantity of two litres represents a very considerable amount of dry lint, the greater part of which would have remained on the bedspreads, had it not been for the filtering arrangement provided.

Thus, there is provided a dyeing process which, when used in particular with tufted articles such as candlewick bedspreads, extracts a significant amount of free lint from the tufted articles. Articles which have been subjected to such a dyeing process thus have considerably less lint than similar articles which have been produced by conventional processes, and the traditional disadvantage ofsuch articles as candlewick bedspreads can therefore be significantly reduced.

Even better results may be obtained by subjecting the candlewick bedspreads, prior to the dyeing process, to a tumbling operation in a tumbling machine through which cold air is passed and exhausted through a filter. It is found that this preliminary tumbling step can remove an appreciable amount of lint before the bedspreads are dyed, and this can be most effective even when used with conventional dyeing processes. However, when a candlewick bedspread has been subjected both to preliminary tumbling and a dyeing process as illustrated, the lint content can be especially low.

Claims (22)

1. A dyeing process comprising the steps of placing both dye liquor and articles to be dyed in a dye vat, extracting dye liquor from the vat, passing the extracted dye liquor through a filter, and recirculating the filtered dye liquor into the vat.

2. A process according to Claim 1, including the step of agitating said articles in the vat.

3. A process according to Claim 2, wherein the vat is a paddle vat.

4. A process according to Claim 1, 2 or 3, including the subsequent step of rinsing the articles in a rinse liquor, extracting rinse liquor from the vat, passing the extracted rinse liquor through the filter, and recirculating the filtered rinse liquor into the vat.

5. A process according to any preceding claim, including the preliminary step of tumbling the articles in a tumbling machine through which gas is passed, and exhausted through a filter.

6. A procees according to any preceding claim, wherein the articles comprise tufted material.

7. A process according to any preceding claim, when carried out in a dye vat according to any one of Claims 9 to 19.

8. A process according to Claim 1 and substantially as hereinbefore decribed.

9. A dye vat adapted to contain dye liquor and articles to be dyed, and comprising an outlet, a filter means, and a pump for extracting dye liquor from said outlet and recirculating the dye liquor into the vat, through said filter means.

10. A dye vat according to Claim 9, wherein the outlet comprises a duct opening into a side wall of the vat.

11. A dye vat according to Claim 9 or 10, wherein the outlet has a grille at the mouth thereof.

12. A dye vat according to Claim 9, 10 or 11, wherein the filter means is disposed at the top of the vat.

1 3. A dye vat according to Claim 12, wherein the filter means comprises a flexible mesh supported in a perforated holder above the dye liquor level in the vat.

14. A dye vat according to Claim 13, wherein said flexible mesh is in the form of a bag.

1 5. A dye vat according to Claim 1 3 or 14, wherein said flexible mesh is of synthetic fibre material.

16. A dye vat according to Claim 13, 14 or 15, wherein said flexible mesh is secured around a discharge pipe.

17. A dye vat according to Claim 16, wherein said discharge pipe has at least one longitudinal slot therein.

1 8. A dye vat according to any one of Claims 9 to 17, being a paddle vat.

1 9. A dye vat substantially as hereinbefore described with reference to the accompanying drawings.

20. A method of dyeing articles of tufted material, including the steps of tumbling the articles in a tumbling machine through which gas is passed and exhausted through a filter, and subsequently dyeing the articles in a dye vat.

21. A method according to Claim 20, including the subsequent step of dyeing the dyed articles in a tumble drying machine.

22. A method according to Claim 20 or 21, wherein the articles are dyed by a process according to any one of Claims 1 to 8.