GB2051159A

GB2051159A - Continuous Treatment of Cloth

Info

Publication number: GB2051159A
Application number: GB8017123A
Authority: GB
Original assignee: Sando Iron Works Co Ltd
Current assignee: Sando Iron Works Co Ltd
Priority date: 1979-05-23
Filing date: 1980-05-23
Publication date: 1981-01-14
Also published as: DE8013619U1; MX150274A; DE3019286A1

Abstract

Continuous treatment of a web of cloth 6 in a pressure steamer 1 having a wet heat internal atmosphere, so as to pre-treat, crimp, wash and set the cloth. The cloth 6 is soaked with an aqueous treating solution containing caustic alkali in tank 42 and is then transported along rollers 7 whilst being subjected to a wet-heat pre- treatment. Then the cloth is passed along a cloth passage a defined by adjacent runs of two net conveyors 81 and 82, whilst jets of washing liquid are directed thereat from nozzles 9 spaced along the length of the passage a. The jets cause the cloth to follow a zig-zag path, liquid issuing from the nozzles being collected and recirculated to the nozzles. The cloth is set by being passed through a cooling tank 52 before leaving the steamer. The rollers 7 can be replaced by an alternative cloth transport device (Figure 2) arranged to apply tension to the cloth, thereby allowing silketting or mercerisation simultaneously to be performed. <IMAGE>

Description

SPECIFICATION Method and Apparatus for the Continuous Treatment of Cloth This invention reiates to the continuous treatment of a cloth, and in particular to methods of and apparatus for the treatment of cloth under conditions of high temperature and high pressure.

Conventionally, such treatments of a cloth as silketting or mercerising, crimping and setting including washing have separately been done in succession after a pre-treatment of the cloth, such as desizing, refining and bleaching. To subject a long cloth continuosly to such treatments, the cloth typically having a length of about 6000 to 9000 m is soaked with a desizing agent, wet-heat treated for about 40 minutes at about 970C in a first Perble Range (the present Applicant's Trade Mark for a particular type of textile treating apparatus) to effect the desizing, whereafter the cloth is washed with water by being passed through a plurality of washing tanks.

Then the cloth is soaked with a refining agent, wet-heat treated again, similarly for about 40 minutes in a second Perble Range to effect the refining, whereafter the cloth is washed, soaked with a caustic alkali solution and squeezed repeatedly with a mangle device, and then the cloth is washed again while passing through a tenter to effect silketting. It will thus be appreciated that a series of treating apparati are needed, and since each treatment takes a considerable time to perform, about 2 to 3 hours are needed to complete all the treatments. The conventional processes thus exhibit a low efficiency, and moreover consume large amounts of heat energy and water. In view of such disadvantages, the present invention aims at offering a method of and apparatus for continuously treating a long cloth, allowing efficient pretreatment, crimping and washing of the cloth.

Accordingly, one aspect of this invention provides a method of continuously treating a web of cloth in a high pressure steamer having an internal atmosphere at an elevated temperature to pretreat, crimp, wash and set the cloth, comprising subjecting the cloth soaked with an aqueous treating solution containing caustic alkali to a wet heat treatment while transporting the cloth with the aid of a cloth guiding device and then transporting the cloth continuously along a cloth passage defined by the gap formed between a pair of endless net conveyors provided one above the other in the steamer whilst jetting a hot washing liquid at the cloth from a plurality of jet nozzles spaced alternately along two opposed sides of the cloth passage, and cooling the cloth by transporting the cloth continuously through cooling water.

Preferably, the wet-heat treatment of the cloth is performed at a temperature in the range of from 1200 to 1 550C. The internal pressure in the steamer should thus be super-atmospheric, and preferably also the internal atmosphere is saturated.

The cloth may be subjected to a predetermined tension during the wet heat treatment thereof, whereby the cloth is simultaneously mercerised.

However, the cloth may instead be transported under conditions of substantially no tension, during the wet heat pre-treatment.

In order to save the energy consumption, it is greatly preferred for the hot washing liquid to be collected after issuing from the nozzles and then recirculated, with replenishment as necessary.

The efficiency of washing can further be enhanced by hot washing the cloth passing along the cloth passage in two steps, the first step taking place along the major part of the passage and comprising crimping and primary washing, and the second step taking place along the outlet portion of the cloth passage and comprising secondary washing of the cloth after sufficient crimping has taken place.

To ensure the cloth is sufficiently crimped, the jets of hot washing liquid should be directed at the cloth with sufficient force to cause the cloth to follow a snake-like path along the cloth passage.

This subjects the cloth to crumpling and beating, thereby effecting crimping.

According to another aspect of this invention, there is provided apparatus for the continuous treatment of a cloth which apparatus comprises a high pressure steamer having means to maintain an internal wet heat atmosphere at high temperature and pressure and adapted for the continuous transport of a web of cloth therethrough, there being provided within the steamer, in succession, a cloth guiding device to transport the cloth continuously whilst the cloth is subjected to a wet-heat treatment, and a pair of endless net conveyors provided one above the other with two adjacent runs substantially parallel and horizontal to define a gap therebetween which serves as a cloth passage through which the cloth can continuously be transported on operation of the conveyors, there being a plurality of jet nozzles spaced along both side of the cloth passage and arranged alternately to direct liquid jets at the cloth passing along the passage, means to recirculate hot washing liquid to the jet nozzles and a cooling tank through which the cloth is passed continuously after leaving the cloth passage but before leaving the steamer.

The cloth guiding device may comprise a plurality of cloth guiding rollers arranged in a horizontal row and along which the cloth can be transported under substantially no tension.

However, when the cloth is to be subjected to silketting or mercerisation, the cloth guiding device may comprise a plurality of cloth guiding rollers arranged so as to define a zigzag path having generally vertically extending runs and along which the cloth can be transported under a predetermined tension.

Preferably, the jet nozzles are divided into two groups, one group lying alongside the major part of the length of the cloth passage and the other group lying alongside the outlet end portion of the cloth passage, there being separate respective means to recirculate the washing liquid issuing from the two groups of nozzles, whereby the washing may more efficiently be accomplished.

It will be appreciated that when cloth is treated according to this invention, several treatments may be effected within one compact high pressure steamer, in an effective and rapid manner, the treatment only taking several tens of seconds. Since the washing liquid may contain a caustic alkali, the washing of the cloth is most efficient, but also the cloth is crimped uniformly and suitably. Thus, the treated cloth may have an excellent 'touch' or'feel' and bulkiness, though only relatively small amounts of heat energy and water are used. The treatment method is therefore suitable for mass production of treated cloth.

By way of example only, two specific embodiments of this invention will now be described in detail, reference being made to the accompanying drawings, in which: Figure 1 is a diagrammatic transverse section of a first embodiment of steamer arranged in accordance with this invention; and Figure 2 is a similar view of a second embodiment of steamer arranged in accordance with this invention.

Referring to Figure 1, there is shown a high pressure steamer body 1 for treating a cloth continuously under wet heat conditions, at a super-atmospheric pressure and at temperature above the boiling point of water. The steamer body 1 is fitted with a cloth inlet 2 and a cloth outlet 3, respectively having an inlet seal mechanism 4 and an outlet seal mechanism 5.

These seal mechanisms allow a cloth 6 to be transported through the steamer body 1 whilst the interior thereof is maintained at a superatmospheric pressure and at an elevated temperature, with no substantial leakage. The inlet seal mechanism 4 comprises a pair of sealing rubber rollers 4, pressed together to define a nip seal through which the cloth is passed, a liquid seal tank 42 provided between the rollers 4, and the steamer interior, and a number of squeeze bars 43 between which the cloth passes as the cloth enters the steamer body. The outlet seal mechanism comprises a pair of sealing rubber rollers 5, pressed together again to define a nip seal through which the cloth is passed, and a slow cooling tank 52 provided between the steamer interior and the sealing rubber rollers 5,.

A plurality of cloth guiding rollers 7 are arranged horizontally within an upper part of the steamer body 1, the cloth 6 being fed thereonto, for continuous transport under conditions of substantially no tension. Steam nozzles 1 5 direct jets of steam on to the cloth 6 passing over the cloth guiding rollers 7.

A pair of endless net conveyors 8, and 82 are provided in a generally parallel and horizontal disposition one above the other, beneath the cloth guiding rollers 7. The two adjacent but opposed runs of the conveyors define a gap which serves as a cloth passage a. The upper run of the upper conveyor 8, also serves to transport the cloth under conditions of substantially no tension, from the discharge end of the guiding rollers 7 to the inlet of the cloth passage a. A plurality of washing solution jet nozzles 9 are arranged to supply jets of hot washing solution at the cloth, the nozzles being disposed alternately above and below the passage a along the major part thereof, to direct the jets through the adjacent run of the respective conveyor.Further jet nozzles 10 (four in the figure) are provided above and below the outlet end portion of the passage a, alternately in the same manner as the nozzles 9. Washing solution catch tanks 11 and 1 2 are positioned to receive washing solution falling from the passage a respectively issuing from the jet nozzles 9 and 10.

The washing solutions accumulating in the catch tanks 11 and 12 are circulated respectively to the jet nozzles 9 and 10 by means of pumps (not shown in the figure) the solutions being replenished occasionally, as necessary. Seam nozzles 1 3 and 14 direct jets of steam at the washing solutions in the catch tanks 11 and 12 respectively.

The continuous treatment of a cloth using this apparatus is as follows. At first, the interior of the steamer body 1 is brought up to and maintained at a temperature within the range of about 1 20C to 1 55 C to provide a wet heat atmosphere. The liquid seal tank 42 is filled with a prescribed treating solution, and the slow cooling tank 52 is filled with cooling water. The treating solution will typically be an aqueous caustic alkali solution. If the cloth is to be simultaneously bleached, thiourea dioxide may be added thereto. The washing solution receiving tanks 11 and 12 are filled with fresh water, the temperature of which is maintained within the range of about 1 20C to 1 550C, by jetting steam from the steam nozzles 13 and 14 into the tanks.

Then, a long web of cloth, for instance composed of cotton yarns, is introduced in the steamer body 1 and fed continuously therethrough. The cloth is soaked with a treating solution containing caustic alkali in liquid seal tank 42, and goes continuously over the surface of the cloth guiding rollers 7 and the upper run of the upper net conveyor 8, under conditions of substantially no tension, while being treated by the wet-heat atmosphere at an elevated temperature. In this way, a wet-heat pretreatment of the cloth is performed.

Then the cloth is transported continuously through the passage a between the net conveyors 8, and 82 on operation thereof, while receiving the jet pressure of the hot washing solution directed thereat from both sides of the passage, out of nozzles 9 and 10. Due to the jet pressure of the solutions jetted at the cloth, the cloth follows a snake-like path as it advances along the passage a, receiving strong beating and crumpling forces. In this way, the washing solution may permeate the yarns of the cloth right to the interior thereof, and thus the cloth is desized, refined and washed effectively, whilst simultaneously being suitably crimped.

The washing solution accumulating in the catch tank 11 contains, besides caustic alkali, such impurities as wax, protein, pectin and ash dissolved from the cloth, particularly if the cloth is composed of cotton yarns and the like, so that the washing solution should have a detergent or soap-like property to increase the washing, desizing and refining effects. These impurities are explained in greater detail below.

Wax. Cotton contains 0.4 to 0.8% wax. Wax is decomposed by the reaction with caustic alkali into fatty acids and alcohols, and the fatty acids thus formed combine with caustic alkali to form soap.

Protein. Cotton contains 0.3 to 0.4% protein, and 80 to 90% thereof is dissolved by treating the cotton with a caustic alkali solution.

Pectin. Pectin, contained in cotton in amounts from 0.6 to 1.2%, is dissolved with caustic alkali by saponification to form alkali pectinate, as a soap.

Ash. Oxides such as potassium oxide, sodium oxide, magnesium oxide and calcium oxide, which are contained in cotton in an amount of 1 to 2% in total, are removed by refining (about 70%) and by bleaching (about 20%).

By repeatedly circulating a washing solution which has a soap effect, as explained above, primary washing of the cloth is done most effectively, together with crimping of the cloth as the washing progresses.

The cloth, having been crimped sufficiently and subjected to primary washing, is further treated as in the preceding step by jetting another hot washing solution at the cloth from the nozzles 10 as the cloth passes through the end portion of the cloth passage a, this other washing solution being recirculated and refreshed as necessary. In this way, a secondary washing can be performed effectively, before the cloth is passed continuously through the cooling tank 52 containing cooling water for setting the cloth. The pre-treatment, crimping and setting of a cloth can all be done quite effectively in this way, in a short time of about 30 to 60 seconds.

Figure 2 shows another embodiment of apparatus of this invention, which apparatus is similar to that described above referring to Figure 1: like parts are given like reference characters and will not be described again. The apparatus differs however from that of Figure 1 in that the plurality of cloth guiding rollers 7 are replaced by another arrangement of cloth guiding rollers 1 6.

Here, the rollers are disposed to define a zig-zag path in an upper part of the steamer with runs extending generally vertically, rollers 16' being mounted to allow the transport of the cloth under a predetermined tension. Only jet nozzles 9 are provided along the cloth passage a, with only one catch tank 11, but of course the nozzles can be divided into two groups and two catch tanks provided, as in the preceding example, to subject the cloth to further washing.

In this apparatus, since the cloth is subjected to a wet-heat treatment whilst under tension, silketting or mercerisation of the cloth can proceed effectively at the same time. In other respects this embodiment is operated in the same manner as the preceding embodiment, and thus this type of apparatus is particularly suitable for the treatment of a cloth containing polyester fibres.

As will be appreciated from the foregoing, cloth is treated in apparatus of this invention by being passed through a high pressure steamer having an internal atmosphere at an elevated temperature and super-atmospheric pressure and humidity. The cloth is first soaked with an aqueous treatment solution containing a caustic alkali, whereafter the cloth is passed continuously through an upper part of the steamer, either under conditions of substantially no tension or under a predetermined tension. After that, the cloth is passed along the treatment passage a, whilst having washing liquid jetted thereat, causing the cloth to follow a snakelike path. On leaving the passage, the cloth is passed through the cooling tank 52 and thence leaves the steamer.

By jetting hot water at the cloth alternately from both sides, the cloth follows a snake-like path, and thus is subjected to strong beating and crumpling forces, and this is particularly effective at crimping and washing the cloth. As a result, the cloth as treated has a soft feel as well as a suitable bulkiness. In this way, the cloth can be pre-treated, crimped, washed and set effectively, in a short time. If the cloth is subjected to a wetheat treatment whilst having a tension applied thereto, silketting or mercerisation of the cloth can also be done simultaneously, presuming the yarns of the cloth are susceptible to such treatments.

Claims

1. A method of continuously treating a web of cloth in a high pressure steamer having an internal atmosphere at an elevated temperature to pretreat, crimp, wash and set the cloth, comprising subjecting the cloth soaked with an aqueous treating solution containing caustic alkali to a wet heat treatment while transporting the cloth with the aid of a cloth guiding device and then transporting the cloth continuously along a cloth passage defined by the gap formed between a pair of endless net conveyors provided one above the other in the steamer whilst jetting a hot washing liquid at the cloth from a plurality of jet nozzles spaced alternately along two opposed sides of the cloth passage, and cooling the cloth by transporting the cloth continuously through cooling water.

2. A method of continuously treating a cloth according to claim 1, in which the wet-heat treatment of the cloth is performed at a temperature in the range of from 1200 to 1 550C.

3. A method of contilaims, in which the cloth is subjected to a predete preceding cermined tension during the wet heat treatment thereof whereby the cloth is simultaneously mercerised.

4. A method of continuously treating a cloth according to any of the preceding claims, in which the hot washing liquid is collected after issuing from the nozzles and is then recirculated, with replenishment as necessary.

5. A method of continuously treating a cloth according to any of the preceding claims, in which the hot washing of the cloth passing along the cloth passage is performed in two steps, the first step taking place along the major part. of the passage and comprising crimping and primary washing, and the second step taking place along the outlet portion of the cloth passage and comprising secondary washing of the cloth after sufficient crimping has taken place.

6. A method according to any of the preceding claims, in which the jets of hot washing liquid are directed at the cloth with sufficient force to cause the cloth to follow a snake-like path along the cloth passage.

7. A method of continuously treating a web of cloth substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.

8. Apparatus for the continuous treatment of a cloth which apparatus comprises a high pressure steamer having means to maintain an internal wet heat atmosphere at high temperature and pressure and adapted for the continuous transport of a web of cloth therethrough, there being provided within the steamer, in succession, a cloth guiding device to transport the cloth continuously whilst the cloth is subjected to a wet-heat treatment, and a pair of endless net conveyors provided one above the other with two adjacent runs substantially parallel and horizontal to define a gap therebetween which serves as a cloth passage through with the cloth can continuously be transported on operation of the conveyors, there being a plurality of jet nozzles spaced along both sides of the cloth passage and arranged alternately to direct liquid jets at the cloth passing along the passage, means to recirculate hot washing liquid to the jet nozzles and a cooling tank through which the cloth is passed continuously after leaving the cloth passage but before leaving the steamer.

9. Apparatus according to claim 8, wherein there is provided means to soak the cloth with an aqueous treating solution as the cloth enters the steamer and prior to the wet heat treatment being performed.

10. Apparatus according to either claim 8 or claim 9, wherein the cloth guiding device comprises a plurality of cloth guiding rollers arranged in a horizontal row and along which the cloth can be transported under substantially no tension.

11. Apparatus according to either claim 8 or claim 9, wherein the cloth guiding device comprises a plurality of cloth guiding rollers arranged so as to define a zigzag path having generally vertically extending runs and along which the cloth can be transported under a predetermined tension.

12. Apparatus according to any of claims 8 to 11, wherein the jet nozzles are divided into two groups, one group lying alongside the major part of the length of the cloth passage and the other group lying alongside the outlet end portion of the cloth passage, there being separate respective means to recirculate the washing liquid issuing from the two groups of nozzles.

1 3. Apparatus according to any of claims 8 to 12, wherein each jet nozzle is disposed to direct washing liquid through the adjacent run of the net conveyor at cloth being transported along the cloth passage.

14. Apparatus according to any of claims 8 to 13, wherein the steamer is fitted with inlet and outlet roll nip seals thereby allowing the continuous transport of cloth into and out of the steamer.

1 5. Apparatus for the continuous treatment of cloth substantially as hereinbefore described with reference to and as illustrated in Figure 1 or in Figure 2 of the accompanying drawings.