GB2052582A

GB2052582A - Hot liquid treatment of a cloth

Info

Publication number: GB2052582A
Application number: GB8019477A
Authority: GB
Original assignee: Sando Iron Works Co Ltd
Current assignee: Sando Iron Works Co Ltd
Priority date: 1979-06-14
Filing date: 1980-06-13
Publication date: 1981-01-28
Also published as: DE3021874A1; DE8015506U1

Abstract

Hot liquid treatment of a cloth, by passing the cloth 8 through a wet- heat treatment chamber 1. A pair of endless net conveyors 2, 2' together define a cloth passage through which the cloth 8 is conveyed, and hot treatment liquid is jetted on to the cloth from nozzles 3 spaced above and below the cloth passage. The cloth 8 is thereby forced to follow a zig-zag path through the cloth passage, thereby to subject the cloth to beating and flexing forces. The cloth 8 may pass along a cloth guiding device (15) [Fig. 4] whilst being subjected to a steaming step from jets (16) prior to entering the cloth passage. The hot treatment liquid may be a caustic alkali solution, whereby the cloth simultaneously is pretreated and beaten and washed. <IMAGE>

Description

SPECIFICATION Apparatus and methods for the hot liquid treatment of a cloth The present invention relates to apparatus for and methods of subjecting a cloth to a liquid treatment in a wet heat treatment chamber, thereby to untwist, crimp and wash the cloth.

The present inventors have made studies on methods and apparatus for continuously untwisting, crimping and washing a web of cloth, particularly a strongly twisted cloth, by applying strong beating and crumpling forces to the cloth. In one method, the cloth is transported through a gap formed between the opposed runs of a pair of parallel endless net conveyors arranged one above the other in a liquid medium whilst a hot fluid is jetted on to the cloth from nozzles spaced on either side of the cloth thereby to vibrate the cloth. There have been other proposals to apply mechanical forces to a cloth to beat and crumple the cloth. However, these conventional methods require a large amount of mechanical or heating energy and water, so that there is a clear need for improved apparatus for and methods of treating a cloth to untwist, crimp and wash the cloth.

The continuous pretreatment of a cloth including desizing, refining and bleaching has conventionally been carried out separately by two different methods - a steaming method and a boiling method. In the steaming method, steam is blown directly to a large quantity of cloth piled in a bundle, so that the wet heat of the steam cannot uniformly be distributed throughout the bundle, and the bundle cannot uniformly be subjected to pretreatment. In addition, due to the non-uniform distribution of wet heat throughout the bundle, parts of the bundle are subjected to tension. In a boiling method, the treatment is carried out in a liquid medium and the cloth is wrinkled frequently, depending on the kind of cloth, and subjected to tension as it is removed from the liquid medium.Thus, it is not possible to obtain a cloth having excellent touch feeling with appropriate bulkiness, stretchability and shrinkability by such conventional methods.

The present inventors have recently developed a perble range which employs a boiling treatment step in combination with a pretreating step for the cloth, but in the perble range the cloth is unavoidably subjected to a tension when it is removed from the boiling treatment tank in the perble range which tends to elongate the cloth. The elongation of a cloth is a serious setback in the production of a higha quality cloth.

It is an aim of this invention to provide an apparatus for and a method of treating a cloth which overcome at least some of the disadvantages encountered with the known apparatus and methods.

According to one aspect of this invention there is provided a hot liquid treatment method for a cloth in a wet-heat treatment chamber, comprising transporting the cloth through a cloth passage defined by the gap between the two adjacent generally parallel runs of two endless net convenyors disposed one above the other and at least partially within the wet heat treatment chamber, and jetting treatment liquid at a superatmospheric temperature on to the cloth from nozzles disposed outside and space along the length of cloth passage alternately thereabove and therebelow so that as the cloth is transported along the cloth passage on operation of the conveyors, the cloth is untwisted, crimped and washed.

By jetting treatment liquid at a superatmospheric temperature on to the cloth from nozzles spaced along the length of the cloth passage, the cloth follows an undulating path under an overall condition of substantially no tension whilst being subjected to strong beating and crumpling forces. The cloth is therefore impregnated uniformly with the said treatment liquid through to the interior thereof and the cloth thereby sufficiently is pretreated, untwisted, crimped and washed in a relatively short time.

Advantageously the gap between the adjacent runs of the conveyor is in the range of from 500 to 200 mm in order to ensure that the cloth receives sufficient vibration and flexing as it passes along the cloth passage. The temperature of the treatment liquid is preferably in the range of from 700C to 1000C and the temperature of the treatment liquid jetted on to the cloth may be increased stepwisely along the length of the cloth passage. In order to reduce wastage of treatment liquid and to conserve energy, the treatment liquid jetted on to the cloth may be collected and re-circulated to the nozzles. The cloth may repeatedly pass through the cloth passage and the free ends of a single length of cloth may be joined to form an endless loop which is repeatedly passed through the cloth passage.The cloth may however be continuously conveyed into and out of the wet-heat treatment chamber.

In another preferred method of this invention the cloth may be subjected to a steam treatment prior to passing through the cloth passage and being subjected to the hot liquid treatment, the steam treatment comprising passing the cloth through a cloth guiding device provided in the wet-heat treatment chamber whilst jetting superheated steam at the cloth. The treatment liquid can be water; or alternatively, if it is wished to effect pretreatment of the cloth simultaneously with the untwisting crimping and washing thereof, the treatment liquid may be a caustic alkali solution.

In another aspect of this invention there is provided an apparatus for the hot liquid treatment of a cloth, comprising a wet-heat treatment chamber having means to maintain therewithin a humid atmosphere at superatmosphericlemperature and means for transporting a cloth continuously therethrough, which transporting means comprises two endless net conveyors arranged one above the other with two opposed runs generally parallel so that the gap therebetween serves as a cloth passage along which the cloth may be passed along, there being a plurality of jet nozzles disposed outside and spaced along the length of, and altèrnately aboveand below, the passage to direct treatment liquid at superatmospheric temperature into the passage through the adjacent runs of the conveyors defining the passage, to allow untwisting, crimping and washing of the cloth as it passes through the cloth passage, and a treatment liquid collection tank arranged beneath the lower net conveyor to collect treatment liquid jetted on to the cloth. Conveniently the nozzles extend transversely to the cloth passage. The treatment liquid collection tank is preferably provided with means to recirculate the treatment liquid collecting therein to the jet nozzles.

Advantageously a plurality of treatment liquid collection tanks are provided beneath the lower net conveyor and spaced along the length thereof, each treatment liquid tank being provided with means to re-circulate the treatment liquid collecting therein to the jet nozzles provided thereabove.

In order to allow a cloth repeatedly to be passed through the cloth passage means may be provided to pass the cloth from the outlet of the cloth passage back to the inlet of the cloth passage.

Conveniently the wet-heat treatment chamber is provided with inlet and outlet seals and means are provided to convey the cloth through the inlet and outlet seals respectively, thereby to allow the cloth continuously to be conveyed into and out of the wet-heat treatment chamber. Advantageously a cloth guiding device is provided above the endless net conveyors through which the cloth is passed before the cloth is introduced into the cloth passage, and a plurality of jet nozzles are provided which are adapted to jet superheated steam on to the cloth as it passes through the cloth guiding device, thereby to effect a steam treatment on the cloth. The cloth guiding device may either comprise a plurality of guide rollers disposed to provide a zig-zag path along which the cloth is passed or it may comprise a further endless net conveyor extending in a generally horizontal direction.

By way of illustration only five 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 sectional view of a first embodiment of apparatus constructed in accordance with this invention.

Figure 2 is a similar view of a second embodiment; Figure 3 is a similar view of a third embodiment; Figure 4 is a similar view of a fourth embodiment; and Figure 5 is a similar view of a fifth embodiment.

Referring initially to Figure 1 , there is shown an apparatus for the treatment of a web of cloth, which subjects the cloth to strong beating and crumpling forces thereby to untwist, crimp and wash the cloth. The apparatus comprises a wet heat treatment chamber 1 for treating a cloth under conditions of wet heat at normal atmospheric pressure. A pair of endless net conveyors 2, 2' are arranged in the treatment chamber 1, one above the other so that the adjacent opposed runs define a gap a therebetween which gap serves as a cloth passage. The endless net conveyors are permeable to liquids and extend generally parallel and horizontal. A plurality of rows of jet nozzles 3 extend transversely to the cloth passage. The rows are disposed alternately above and below the cloth passage and are spaced along the length of the passage.

A treatment liquid collection tank 4 is provided in the lower part of the wet heat treatment chamber 1 beneath the lower net conveyor 2' to collect treatment liquid jetted from nozzles 3. The temperatures of the treatment liquid 5 in the collection tank 4 is controlled by means of a temperature regulator 7 and a steam jet pipe 6. The treatment liquid 5 accumulating in the collection tank 4 is re circulated to the jet nozzles 3 by means of a pump (not shown in the Figure).

The factors which establish the preferred range of values for the width of the gap a between the two net conveyors 2 and 2' will now be described. The width of the gap a should be of such a size that the cloth is strongly beaten and crumpled and thereby becomes sufficiently permeable to the treatment liquid as it passes along the cloth passage.

Although an appropriate width of the gap depends on the thickness and flexibility of the cloth to be treated and on the jetting pressure of the treatment liquid, it is preferable that the height of the snaky undulations of the cloth (which is limited by the width of the gap) is as large as possible. This is because the cloth receives a strong flexing action by the jetting pressure of the treating liquid while the cloth is moving up and down as it follows an undulating path, and the flexing action assists in rendering the cloth permeable to the treatment liquid and simultaneously to beat and crumple the cloth. When the gap between the two conveyors is narrow, the length of travel of the cloth from the top of the cloth passage to the bottom thereof as the cloth follows an undulating path is relatively short and the cloth is insufficiently flexed. On the other hand, when the gap is too wide, the cloth is not beaten sufficiently against the conveyor, and the force of the jets is insufficient to force the cloth to follow an undulating path. The cloth thus floats up in the gap, does not contact the conveyors and therefore the cloth is not transported smoothly along the cloth passage on operation of the two conveyors.

To establish a preferred range of values for the size of the gap a, the length b of the cloth contacting the conveyor for each separate undulation and the amount of shrinkage of the cloth were determined experimentally for a range of different values of size of the gap a and for cloths of different kinds. The jetting pressure of the treating liquid and the pitch of the jet nozzles were kept constant. The results are shown in Table 1.

Conditions: Jetting speed 30 m/sec.

Temperature 1 000C Pitch of jet nozzles 350 mm Width of jet nozzles 8 mm Width Length Cloths tested: cm cm No.1 T/CGabardine 91.8. x 103.9 No. 2 T/C Weather 90.6 x 104.0 No. 3 Cotton Gabardine 92.6 x 104.6 No. 4 T/C Mixed Weave 107.8 x 100.7 TABLE 1 Test of the formation of snaky undulations

Width of the gap a in mm Cloth 20 50 100 150 200 ' 250 bin mm 130 120 -112 T 110 88 50 No. 1 Width in mm* 91.4 91.0 90.0 90.2 90.6 90.6 Length in mm** 103.4 101.8 100.8 101.2 101.8 103.2 6 in mm 143 115 110 110 95 60 No. 2 Width in mm* 90.3 90.0 89.0 89.2 90.0 89.8 Length in mm** 103.5 102.2 101;5 101.8 102.6 103.2 bin mm 104 120 115 115. 95 55 No. 3 Width in mm* 92 - 90.1 90.5 90.8 91.0 Length in mm** 104 - 100.9 101.2 101.2 103.7 bin mm 140 120 110 100 85 65 No. 4 Width in mm* 107.2 - 103.4 103.6 103.6 107.0 Length in mm** 100.7 - 97.5 97.4 97.5 97.5 * Width of the cloth after treatment.

** Length of the cloth after treatment.

The cloth should smoothly be conveyed through the cloth passage under an overall condition of substantially no tension-and receive a strong flexing action thereby to follow an undulating path under the influence of the jetting force of the treatment liquid. The cloth will then achieve sufficient shrinkage in the lengthwise and crosswise directions and thereby form fine crimps. In order to achieve the above conditions, it has been found that the length b of the cloth contracting the conveyor during each undulation should lie in the range of from 85 to 120 mm.

It can be seen from Table 1, which shows the test results for a variety of different cloths, that in order to achieve a sufficient value of the length b for a variety of cloths, the width of the gap a should lie in the range of from 50 to 200 mm. Outside this range, it is difficult to achieve sufficient shrinkage of the cloth.

The untwisting, crimping and washing of a length of cloth using this apparatus is performed as follows. The cloth to be treated may be, for example, a woven cloth or a knitted georgette comprising strongly twisted yarns of 100% polyester filaments and a broad class cloth comprising 65% polyester and 35% cotton. The washing water 5 in the liquid collection tank 4 is heated to a temperature of slightly below 1000C. A length of cloth 8 to be treated is introduced into the cloth passage between the two conveyors 2, 2' and the conveyors are operated in the direction shown by the arrows in Figure 1 to draw the cloth through the cloth passage.As the cloth passes along the passage, the washing water 5 in the collection tank 4 is supplied by a pump to the jet nozzles 3 from where the washing water is jetted on to the cloth. The jets are sufficiently strong to cause the cloth 8 to take up a 'snakey' or zig-zag configuration so that as the cloth advances along the cloth passage the cloth follows an undulating path. The cloth 8 is thus beaten repeatedly and,alternately against the two net conveyors 2 and 2', and thus is subjected to beating and crimpling forces. At the same time the cloth is subjected to flexing actions as it follows an undulating path, which aids complete impregnation of the cloth with the washing water. The cloth is untwisted, crimped and washed effectively and uniformly and the treated cloth has sufficient stretching and shrinking qualities.

Figure 2 shows a second embodiment of apparatus of this invention, somewhat similar to that just described: like parts are given like reference characters and will not be described in detail again. The embodiment of Figure 2 differs from that shown in Figure 1 in that there are provided three treatment liquid collection tanks 4" 42 and 43. The three liquid collection tanks are arranged beneath, and spaced along, the length of the lower net conveyor 2'. The liquid collection tanks collect the washing water 5 jetted from the net nozzles 3, and the washing water 5 is recirculated separately from each collection tank 4 to the nozzles 3 positioned thereabove.

The water in the liquid collection tanks 4" 42 and 43 are maintained at temperatures of approximately 750C, 850C and 950C respectively. The operation of this embodiment is similar to that of the preceding embodiment. By elevating the temperature of the washing water stepwise, the untwisting and crimping of the cloth is carried out more effectively to give uniform and fine crimps.

Moreover, washing is done effectively, particularly if the apparatus is modified so that rather than recirculating washing water from liquid-collection tank 43, to the associated nozzles 3,fresh washing water continuously is supplied to those nozzles.

Figure 3 shows a third embodiment of apparatus, broadly similar to that of Figure 1 and like parts are given like reference characters. This embodiment of apparatus is modified repeatedly to treat a loop of cloth. A length of cloth is made into an endless loop by sewing together the ends thereof, and then circulated repeatedly through the cloth passage in the wet heat treatment chamber 1 shown in the Figure.

It is preferable to elevate the temperature of the washing water stepwise, for instance, from approximately 700C to 850C and then to 980C as the cloth circulates repeatedly through the cloth passage in the wet heat treatment chamber 1. The wet treatment chamber can then subsequently be cooled slowly to a temperature of approximately 500C to untwist and crimp the cloth. As in the previous embodiment, towards the end of the treatment, fresh washing water may be supplied to the nozzles, rather than water which has been re-circulated from the liquid collection tank 4.

Figure 4 shows an embodiment of apparatus to subject a cloth to a steaming step prior to a boiling step thereby allowing simultaneous pretreatment of the cloth. Like parts to those of the previous embodiments are given like reference characters. The wet heat treatment chamber is fitted with inlet and outlet liquid sealing tanks 13 and 14 respectively at the cloth inlet 11 and the cloth outlet 12.

These sealing tanks are arranged to allow the continuous passage of a cloth through the treatment chamber 1 whilst substantially preventing leakage of the internal wet heat atmosphere. In an upper part of the wet heat treatment chamber 1, a plurality of guide rolls 1 5 are provided to constrain the cloth to follow a zig-zag path in the wet heat treatment chamber prior to the cloth entering the cloth passage. A plurality of steam jet pipes 1 6 are provided at one end of the wet heat treatment chamber which subject the cloth to a steaming or wet heat treatment as the cloth commences to pass around the guide rolls. A pair of endless net conveyors 2 and 2' fitted with a plurality of jet nozzles 3 are arranged beneath the guide rolls 1 5 for transporting the cloth and jetting a treating liquid to the cloth as described in the preceding embodiments.The width of the gap a between the two conveyors, which defines the cloth passage, should lie in the range of from 50 to 200 mm, for the reasons discussed in relation to the first embodiment.

Continuous treatment of a long cloth using this apparatus is carried out as follows. At first, the wet heat treatment chamber 1 and the treatment liquid 5 in the treatment liquid collection tank 4 is heated to a temperature of approximately 950C. The guide rolls 1 5 are operated and at the same time the two net conveyors 2 and 2' are rotated in the direction of the arrows in Figure 4. The treatment liquid 5 may be an aqueous caustic alkali solution so that the cloth is simultaneously pretreated and untwisted and crimped. Thus, a cloth to be treated is passed continuously around the guide rolls 1 5 where initially it is subjected to a steaming step, thereafter to a wet treatment, and finally the cloth is advanced through the cloth passage defined by the upper and lower net conveyors 2, 2'.Superheated steam is jetted to the cloth from steam jet pipes 1 6, and treatment liquid is jetted on to the cloth at a temperature of approximately 950C from the jet nozzles 3.

The cloth is uniformly swollen in the steaming step. and then subjected to a boiling step as in the preceding embodiments. Thus the cloth obtained is pretreated effectively simultaneously with the untwisting and crimping of the cloth. The cloth obtained has excellent touch, stretchability, shrinkability and bulkiness properties.

Figure 5 illustrates a fifth embodiment of apparatus of this invention, somewhat similar to that just described: like parts are given like reference characters and will not be described in detail again. The embodiment of Figure 5 differs from that of Figure 4 in that a further endless net conveyor 1 7 is provided instead of the guide rolls 1 5 to carry the cloth 8 as it is subjected to a steaming process. The further net conveyor 17 is arranged above the upper net conveyor 2 within the wet heat treatment chamber 1. After entering the wet heat treatment chamber 1, the cloth 8 is supplied to the upper run of conveyor 1 7 and is then carried by the conveyor 1 7 in a substantially tensionless condition whilst being subjected to a steaming treatment by steam issuing from steam jet pipes 1 6. The cloth 8 is then subjected to a wet heat treatment, whereafter the cloth is advanced through the cloth passage.

Since the steaming treatment is performed on the cloth when the cloth is in a condition of substantially no tension, no elongation of the cloth takes place during steaming even when the cloth being treated is a knitted cloth. This embodiment of apparatus is particularly suitable for pretreating, untwisting and crimping a knitted cloth.

As will be appreciated from the foregoing, in the present invention a cloth may be pretreated, untwisted, crimped and washed in a relatively short time using a simple apparatus, thereby reducing energy consumption and making economic use of materials and other resources. The cloth treated is suitably crimped to give the cloth excellent touch, bulkiness, stretchability and shrinkability properties.

Claims

1. A hot liquid treatment method for a cloth in a wet-heat treatment chamber, comprising transporting the cloth through a cloth passaged defined by the gap between the two adjacent generally parallel runs of two endless net conveyors disposed one above the other and at least partialiy within the wet heat treatment chamber, and jetting treatment liquid at a superatmospheric temperature on to the cloth from nozzles disposed outside and spaced along the length of cloth passage alternately thereabove and therebelow so that as the cloth is transported along the cloth passage on operation of the conveyors, the cloth is untwisted, crimped and washed.

2. A method as claimed in claim 1, in which the gap between the adjacent runs of the conveyor is in the range of from 50 to 200 mm.

3. A method as claimed in claim 1 or claim 2, in which the temperature of the treatment liquid is in the range of from 700C to 1 000C.

4. A method as claimed in any of the preceding claims wherein the treatment liquid jetted on to the cloth subsequently is collected and re-circulated to the nozzles.

5. A method as claimed in any of the preceding claims, in which the temperature of the treatment liquid jetted on to the cloth increases stepwisely along the length of the cloth passage.

6. A method as claimed in any of the preceding claims, in which a length of cloth is repeatedly passed through the cloth passage.

7. A method as claimed in claim 6, in which the two free ends of a length of cloth are joined to form an endless loop which is repeatedly passed through the cloth passage.

8. A method as claimed in any of claims 1 to 6, in which the cloth is continuously conveyed into and out of the wet-heat-treatment chamber.

9. A method as claimed in any of the preceding claims, in which the cloth is subjected to a steam treatment prior to the hot liquid treatment, the steam treatment comprising passing the cloth through a cloth guiding device provided in the wet-heat treatment chamber whilst jetting superheated steam at the cloth.

1 0. A method as claimed in any of the preceding claims, in which the treatment liquid is water.

11. A method as claimed in any of claims 1 to 9, in which the treatment liquid is a caustic alkali solution, thereby to allow pretreatment of the cloth simultaneously with the untwisting, crimping and washing thereof.

12. A method for treating a cloth substantially as hereinbefore described with reference to any of Figures 1 to 5 of the accompanying drawings.

13. An apparatus for the hot liquid treatment of a cloth, comprising a wet-heat treatment chamber hiing means to maintain therewithin a humid atmosphere at superatmospheric temperature and means for transporting a cloth continuously therethrough, which transporting means comprises two endless net conveyors arrange one above the other with two opposed runs generally parallel so that the gap therebetween serves as a cloth passage along which the cloth may be passsed, there being a plurality of jet nozzles disposed outside and spaced along the length of, and alternately above and below, the passage to direct treatment liquid at superatmospheric temperature into the passage through the adjacent runs of the conveyors defining the passage, to allow untwisting, crimping and washing of the cloth as it passes through the cloth passage, and a treatment liquid collection tank arranged beneath the lower net conveyor to collect treatment liquid jetted on to the cloth.

14. Apparatus as claimed in claim 13, wherein the nozzles extend transversely to the cloth passage.

1 5. Apparatus as claimed in claim 13 or claim 1 4, wherein the gap between the opposed runs of the conveyor lies within the range of from 50 to 200 mm.

1 6. Apparatus as claimed in any of claims 13 to 1 5, wherein the treatment liquid collection tank is provided with means to recirculate the treatment liquid collecting therein to the jet nozzles.

1 7. Apparatus as claimed in claim 1 5, wherein there are provided a plurality of treatment liquid collection tanks beneath the lower net conveyor and spaced along the length thereof, each treatment liquid tank being provided with means to re-circulate the treatment liquid collecting therein to the jet nozzles provided thereabove.

1 8. Apparatus as claimed in any of claims 13 to 1 7, wherein there is provided means to pass the cloth from the outlet of the cloth passage back to the inlet of the cloth passage.

1 9. Apparatus as claimed in any of claims 13 to 1 7, wherein the wet-heat treatment chamber is provided with inlet and outlet seals and means are provided to convey the cloth through the inlet and outlet seals respectively, thereby to allow the cloth continuously to be conveyed into and out of the wetheat treatment chamber.

20. Apparatus as claimed in any of claims 13 to 1 9, wherein a cloth guiding device is provided above the endless net conveyors through which the cloth is passed before the cloth is introduced into the cloth passage, and a plurality of jet nozzles are provided which are adapted to jet superheated steam on to the cloth as it passes through the cloth guiding device, thereby to effect a steam treatment on the cloth.

21. Apparatus as claimed in claim 20, wherein the cloth guiding device comprises a plurality of guide rollers which are disposed to provide a zig-zag path along which the cloth is passed and the plurality of jet nozzles are disposed to either side of, and spaced along, the zig-zag path.

22. Apparatus as claimed in claim 20 wherein the cloth guiding device comprises a further endless net conveyor extending in a generally horizonta! direction.

23. Apparatus for treating a cloth, substantially as hereinbefore described with reference to and as illustrated in any of Figures 1 to 5 of the accompanying drawings.