GB1558610A

GB1558610A - Method and apparatus for continously mercerising a textileweb

Info

Publication number: GB1558610A
Application number: GB41084/76A
Authority: GB
Original assignee: Kleinewefers Industrie Co GmbH and Co KG
Current assignee: Kleinewefers Industrie Co GmbH and Co KG
Priority date: 1975-10-04
Filing date: 1976-10-04
Publication date: 1980-01-09
Also published as: DE2544494A1; CH612559B; NL7610928A; BR7606572A; JPS5415960B2; CH612559GA3; JPS5246196A

Abstract

Mercerisation is carried out under customary temperature and concentration conditions of the liquor, i.e. at a temperature of 8-30 DEG C and a concentration of 20-55 DEG Bé, after deaeration of the moving textile web by applying vacuum. The duration of impregnation is at most 10 s, and the subsequent residence time outside the impregnating bath 30-60 s. During the entire impregnation and residence time, the textile web is maintained in a tight strand of guiding. This results in instantaneous penetration of the mercerising liquor during impregnation. The tight strand of guiding is effected in a shortened apparatus in which the textile web is guided in a short liquor container over reaction rolls close to one another. The number of reaction rolls is at least three to six times that of the dipping rolls. The tight strand of guiding prevents shrinkage and the resulting ejection of the liquor from the textile web. This enables a shorter treatment time. Since the liquor bath used receives only a relatively small amount of liquor, cooling of the liquor as well as recirculating of the liquor can be dispensed with.

Description

(54) METHOD AND APPARATUS FOR CONTINUOUSLY MERCERISING A TEXTILE WEB (71) We, KLEINEWAFERS INDUSTRIE COMPANIE GMBH, of Kleinewefers Kalanderstrasse, 415 Krefeld, Germany, a German Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : The invention relates to a method and apparatus for continuously mercerising a textile web by passing the same through a vacuum and directly thereafter passing it with close-contact cloth guidance over the rollers of a lye bath.

It is known to pass the textile web continuously with slack cloth guidance through a lye bath for mercerising so that the lye taken up by the textile web is subsequently able to react with the freely passing web, a process accompanied by shrinkage of the cloth which is subsequently stabilized by means of a chain. On the one hand this method calls for a large lye tank with a corresponding charge and on the other hand it calls for a device, such as the chain, which stretches the shrunk textile web in the longitudinal and transverse directions.

In a second known mercerising process the textile web is impregnated, with closecontact cloth guidance for between 45 and 60 seconds in a large lye vessel followed by stabilization under firm contact on rollers and with the supply of rinsing liquor and hot water. The cloth guidance of the textile web under continuous contact with rollers in this known mercerising process obviates the need for a chain which stretches the textile web in the transverse and longitudinal direction after it leaves the lye tank but this still leaves the disadvantage that the lye vessel must ensure a process passage time of 45-60 seconds. This calls for a long lye tank and more particularly for a correspondingly large quantity of lye which must not only be circulated but must also be cooled in order to dissipate the heat which results from the mercerising process.

British Patent Specification 1485756 discloses a method for mercerising textile webs, in which method the impregnating time in the lye bath is substantially reduced, to 10 seconds or less, if the lye temperature is close to the boiling temperature of the NaOH concentration in use. This known method therefore calls for constant heating of the lye bath. It has also been proposed (German Patent Specification OS 16 109903 to expose a textile web to a vacuum before feeding it into a treatment bath and in this method the textile web is conveyed directly from the vacuum chamber to the treatment bath. This is intended to improve penetration of the treatment liquid between the fibres of the textile web.

The present invention is applied at this stage. It intends to provide a method which achieves not only a shorter treatment time for the material but also achieves simplification in the design of the apparatus in use, namely shortening of the apparatus, also the elimination of a circulating circuit and cooling of circulated lye.

The present invention resides in a method for the continuous mercerising of a textile web which is guided through a vacuum and directly adjoining thereto is passed with substantially continuous contact over closely spaced rollers of a lye bath at 8 to 30"C and 20 to 350 Bé, characterized in that the textile web is guided through the lye bath for a maximum of 10 seconds, is subsequently guided from the last lye bath roller under substantially continuous contact to a series of closely spaced rollers which is clear of the bath and is guided for 30 to 60 seconds through said series of rollers with substantially continuous contact, and is then stabilized. The lye bath has the conventional concentration (density 20 to 35"by and temperature 8 to 30-0 C).

"Stabilising" means washing under controlled tension.

The invention proceeds from the idea that, depending on the kind of textile web, the fibres of the textile material swell after at most 10 seconds, thus preventing any further substantial absorption of lye by the textile web. After the above-mentioned period, in which maximum or nearly maximum absorption of lye and penetration to the core of the fibre are completed, the textile web is conveyed, with substantially continuous surface contact, from the last roller of the bath - where appropriate through the interposition of a pair of Foulard rollers-to the first roller of the said series of rollers which is clear of the bath and where the textile web undergoes, still with substantially continuous surface contact, the reaction and activating time of the lye, shrinkage of the textile web being however impossible because of the substantially continuous surface contact of the web with the rollers. The web is substantially always in contact with a roller, the gaps between successive rollers being no greater than is necessary to accommodate the web. In this way, lateral shrinkage of the web is prevented, since there are no free intermediate regions of the web path in which lateral shrinkage could take place.

In a preferred apparatus for performing the method, the first roller of a lye bath is partially surrounded in known manner (German Patent Specification OS 21 57 257) by a vacuum cap the bottom of which is immersed in the lye bath, and the lye -tank has at most three rollers which are immersed in the lye bath, the ratio of the number of rollers of the bath to the number of rollers of the said series or reaction part being at least 1: 3 i.e., the lye bath has only a fraction of the rollers of the reaction part. Advantageously, the series of reaction rollers is constructed as a vertical roller column following the horizontal lye bath.

Since the lye bath contains only a relatively small quantity of lye cooling as well as recirculation thereof can be omitted.

Since the series of reaction rollers can be constructed as a vertical roller column, it provides a substantial saving of space compared with horizontal rows of rollers in horizontal lye baths.

One embodiment of apparatus according to the invention is illustrated in the accompanying drawing.

The textile web W runs in the direction of arrow P over a row of closely spaced inlet rollers 1 and a feed roller 2 into a vacuum cap 3, as described in detail in German Patent Specification OS 2,157,257, the bottom portion of the said vacuum cap being immersed in a lye bath 4 in a tank 5.

After passing around a roller 6, against which tthe vacuum cap can be thrust by means of a hydraulic cylinder 7, the textile web W passing between the cap and the roller, the web is guided directly, continuous contact between the web and rollers, to a roller 8 and to closely spaced further rollers 9, 10 of the lye bath, the lye being conducted through pipes 11, 12 to the textile web. The passage of the textile web through the tank 5, i.e. the lye bath, takes a maximum of 10 seconds.

After leaving the roller 10 the textile web passes, also under continuous surface contact, between closely spaced rollers 13, 14 which form a Foulard before being conveyed directly to the first roller 15 of a vertical reaction roller column 16 which comprises two vertical parallel rows 17, 18 of closely spaced rollers 19, in which configuration the textile web is clear of the bath and is conducted without the addition of lye directly from one roller 19 to the next roller, i.e.

with continuous contact between the web and the rollers.

The vertical column of the reaction part adjoins a horizontal section 20 which a stabilizing part 21 adjoins.

As shown by the drawing, the lye bath is very short and extends only over the length a. It has a small capacity and contains only four rollers; the reaction part contains a number of rollers which is several times higher but these can be arranged vertically and are clear of the bath. The number of rollers of the reaction part is at least 3 times as large as the number of rollers of the lye bath, which is subject to the conventional conditions for mercerising, viz. 8 to 30"C and 20 to 35'0B6.

WHAT WE CLAIM IS: 1. A method for the continuous mercerising of a textile web which is guided through a vacuum and directly adjoining thereto is passed with substantially continuous contact over closely spaced rollers of a lye bath at 8 to 30"C and 20 to 350Be', characterised in that the textile web is guided through the lye bath for a maximum of 10 seconds, is subsequently guided from the last lye bath roller under substantially continuous contact to a series ,of closely spaced rollers which is clear of the bath and is guided for 30 to 60 seconds through said series of rollers with substantially continuous contact, and is then stabilized.

2. Apparatus for the continuous mercerisation of a textile web by the method according to claim 1, comprising a lye tank containing not more than three closely spaced rollers which in operation are immersed in the lye bath in the tank, a vacuum cap which partially surrounds the firstly tank roller and of which the bottom

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 35"by and temperature 8 to 30-0 C). "Stabilising" means washing under controlled tension. The invention proceeds from the idea that, depending on the kind of textile web, the fibres of the textile material swell after at most 10 seconds, thus preventing any further substantial absorption of lye by the textile web. After the above-mentioned period, in which maximum or nearly maximum absorption of lye and penetration to the core of the fibre are completed, the textile web is conveyed, with substantially continuous surface contact, from the last roller of the bath - where appropriate through the interposition of a pair of Foulard rollers-to the first roller of the said series of rollers which is clear of the bath and where the textile web undergoes, still with substantially continuous surface contact, the reaction and activating time of the lye, shrinkage of the textile web being however impossible because of the substantially continuous surface contact of the web with the rollers. The web is substantially always in contact with a roller, the gaps between successive rollers being no greater than is necessary to accommodate the web. In this way, lateral shrinkage of the web is prevented, since there are no free intermediate regions of the web path in which lateral shrinkage could take place. In a preferred apparatus for performing the method, the first roller of a lye bath is partially surrounded in known manner (German Patent Specification OS 21 57 257) by a vacuum cap the bottom of which is immersed in the lye bath, and the lye -tank has at most three rollers which are immersed in the lye bath, the ratio of the number of rollers of the bath to the number of rollers of the said series or reaction part being at least 1: 3 i.e., the lye bath has only a fraction of the rollers of the reaction part. Advantageously, the series of reaction rollers is constructed as a vertical roller column following the horizontal lye bath. Since the lye bath contains only a relatively small quantity of lye cooling as well as recirculation thereof can be omitted. Since the series of reaction rollers can be constructed as a vertical roller column, it provides a substantial saving of space compared with horizontal rows of rollers in horizontal lye baths. One embodiment of apparatus according to the invention is illustrated in the accompanying drawing. The textile web W runs in the direction of arrow P over a row of closely spaced inlet rollers 1 and a feed roller 2 into a vacuum cap 3, as described in detail in German Patent Specification OS 2,157,257, the bottom portion of the said vacuum cap being immersed in a lye bath 4 in a tank 5. After passing around a roller 6, against which tthe vacuum cap can be thrust by means of a hydraulic cylinder 7, the textile web W passing between the cap and the roller, the web is guided directly, continuous contact between the web and rollers, to a roller 8 and to closely spaced further rollers 9, 10 of the lye bath, the lye being conducted through pipes 11, 12 to the textile web. The passage of the textile web through the tank 5, i.e. the lye bath, takes a maximum of 10 seconds. After leaving the roller 10 the textile web passes, also under continuous surface contact, between closely spaced rollers 13, 14 which form a Foulard before being conveyed directly to the first roller 15 of a vertical reaction roller column 16 which comprises two vertical parallel rows 17, 18 of closely spaced rollers 19, in which configuration the textile web is clear of the bath and is conducted without the addition of lye directly from one roller 19 to the next roller, i.e. with continuous contact between the web and the rollers. The vertical column of the reaction part adjoins a horizontal section 20 which a stabilizing part 21 adjoins. As shown by the drawing, the lye bath is very short and extends only over the length a. It has a small capacity and contains only four rollers; the reaction part contains a number of rollers which is several times higher but these can be arranged vertically and are clear of the bath. The number of rollers of the reaction part is at least 3 times as large as the number of rollers of the lye bath, which is subject to the conventional conditions for mercerising, viz. 8 to 30"C and 20 to 35'0B6. WHAT WE CLAIM IS:

1. A method for the continuous mercerising of a textile web which is guided through a vacuum and directly adjoining thereto is passed with substantially continuous contact over closely spaced rollers of a lye bath at 8 to 30"C and 20 to 350Be', characterised in that the textile web is guided through the lye bath for a maximum of 10 seconds, is subsequently guided from the last lye bath roller under substantially continuous contact to a series ,of closely spaced rollers which is clear of the bath and is guided for 30 to 60 seconds through said series of rollers with substantially continuous contact, and is then stabilized.

is immersed in the lye bath, a series of closely spaced rollers clear of the bath and having at least three times as many rollers as the number of lye bath rollers, and stabilising means following the said series of rollers.

3. Apparatus according to claim 2, characterised in that the series of rollers is a vertical column of rollers following the lye tank.

4. Apparatus according to claim 2 or 3, characterised by the provision of squeeze means between the lye tank and the series of rollers.

5. A method of mercerizing a textile web substantially as herein described with reference to the accompanying drawing.

6. Apparatus for mercerising a textile web, substantially as herein described with reference to the accompanying drawing.

7. A textile web when mercerised by the method or apparatus claimed in any of the preceding claims.