GB2054684A

GB2054684A - A Method and Apparatus for the Untwisting of Cloth

Info

Publication number: GB2054684A
Application number: GB8021309A
Authority: GB
Original assignee: Sando Iron Works Co Ltd
Current assignee: Sando Iron Works Co Ltd
Priority date: 1979-06-29
Filing date: 1980-06-30
Publication date: 1981-02-18
Also published as: DE3023000A1; MX153682A; JPS5855264B2; JPS569469A; GB2054684B

Abstract

In a method and apparatus for the continuous untwisting of a cloth, the cloth is passed along a cloth passage defined by the gaps a and b between two pairs of endless net conveyors 2, 2' and 14, 14' provided in wet heat treatment chambers 1 and 9 respectively. Hot liquid jet pipes 31, 31', 32, 32', 15 and 15' are disposed to direct jets of liquid at the cloth passing along the cloth passage thereby to cause the cloth to follow a zigzag path on the cloth is advanced along the cloth passage. This subjects the cloth to beating and crumpling forces which untwist and crimp the cloth. The temperature of the water jets is raised stepwise to ensure efficient swelling and untwisting of the cloth, from about 70 DEG C to about 100 DEG in chamber 1, and the temperature of the jets in chamber 9 lies in the range of from 100 DEG C to 150 DEG C. The pressure in the chamber 9 is above atmospheric. <IMAGE>

Description

SPECIFICATION A Method and Apparatus for the Untwisting of Cloth This invention relates to a method and an apparatus for the continuous untwisting of a long cloth which may for instance be a knitted or woven cloth.

When a cloth, and particularly one being strongly twisted and hence having about 600 to 2500 twists per metre, is beaten and crumpled repeatedly, the yarns of the cloth become untwisted and the cloth is crimped to produce a different type of cloth, such as crepe (croepe de Chine) or georgette.

A conventional method for untwisting and crimping a cloth is a batch process in which relatively short lengths of cloth are wound round a frame and have their ends sewn together to prevent the unwinding thereof, and a number of such frames are then placed in a drum which is rotated under conditions of wet heat. This gives a considerable mechanical impact to the frames carrying the cloths, and the temperature within the drum is raised gradually up to about 1 000C, whereafter the drum is cooled slowly down to about 400 C. Finally, the drum is opened and the frames carrying the crimped cloth are removed.

This conventional method has various drawbacks, such as: a) because only cloths having a prescribed length may be wound round the frame, the apparatus cannot be used with many runs of cloth without wastage; b) since the cloth wound round the frame is sewn up, the crimping is inhibited; c) the treatment of the cloth is a discontinuous batch process, and thus not suitable for massproductivity; d) since the drum must be opened between batches, the hot wet atmosphere in the drum is lost completely, leading to much energy wastage; and e) since it is difficult to maintain the wet heat cycle constant from one batch to the next, it is hardly possible to obtain uniform results.

In an attempt to reduce such drawbacks, the present inventors have recently proposed a continuous method for the untwisting of a long knitted or woven cloth comprising subjecting the cloth to a wet heat treatment in which the treating temperature is raised stepwise from 700 to 1 000C under conditions of normal atmospheric pressure, while subjecting the cloth to the forces of jets of hot water so as to untwist the yarns constituting the cloth and to crimp the cloth. The present invention relates to an improvement of that proposal, resulting from detailed studies thereof.

According to one aspect of this invention, there is provided a method for continuously untwisting a cloth, comprising passing the cloth along a cloth passage defined by the gap between two adjacent runs of two endless net conveyors respectively arranged one above the other with said runs spaced and substantially parallel, the directing jets of hot liquid at the cloth being passed along the passage alternately from the two sides of the passage thereby causing the cloth to follow a zigzag path as the cloth is advanced along the passage, the temperature of the hot liquid jets being increased stepwise from a temperature below the boiling point of water to a temperature thereabove along the length of the passage, whereby the jets subject the cloth to beating and crumpling forces which swell, untwist and crimp the cloth.

It is greatly preferred for the temperature of the liquid jets to be raised stepwise from about 700 to about 1 50 C, and it is preferable to carry out the wet heat treatment in two stages, a primary untwisting being within a temperature range from about 700 to about 1000C under normal atmospheric pressure, and a secondary untwisting within a temperature range from about 1000 to about 1 500C, or usually to about 1300C, under elevated pressure. In this way, a cloth can continuously and effectively be untwisted to produce a crimped article such as crepe and georgette having fine and excellent crimps uniformly all over the cloth with no formation of irregular and coarse crimps.

According to another aspect of this invention apparatus for the continuous untwisting of cloth comprises a first wet heat treatment chamber the interior of which is arranged to be at normal atmospheric pressure and a second wet heat treatment chamber the interior of which is arranged to be at a superatmospheric temperature, pressure and humidity, each chamber having provided therein a pair of endless net conveyors arranged one above the other with the adjacent runs of the two conveyors respectively spaced apart and parallel thereby to define a gap serving as a cloth passage, a plurality of liquid jet pipes disposed alternately above and below the cloth passage to direct jets of hot liquid into the cloth passage through the adjacent conveyor run, and supply means to supply liquid under pressure to the jet pipes which means is arranged to increase stepwise the temperature of the jetted liquid. It will thus be appreciated that primaru untwisting of a cloth in the apparatus of this invention is done by passing the cloth under conditions of substantially no tension continuously through a gap formed between a pair of endless net conveyors provided one above the other in the first wet heat treatment chamber, and causing the cloth to follow a zig-zag path along the gap by means of jets of hot water the temperature of which is raised stepwise from, for example, about 700 to about 1000C. Due to the jetting pressure of the hot water, the cloth receives strong beating forces which untwist the yarns constituting the cloth and also crimp the cloth.The secondary untwisting of the cloth is done similarly, but in the second treatment chamber and at a temperature is the range of for example from about 1000 to about 1300C.

Catch tanks are preferably disposed within both treatment chambers to catch liquid issuing from the jet pipes, the supply means being arranged to recirculate the liquid collecting in the catch tanks. In this way, water and energy requirements can be minimised.

By way of example only, one specific embodiment of this invention will now be described, reference being made to the accompanying drawing, which shows a schematic part-sectional view of the embodiment of apparatus constructed in accordance with the present invention.

The apparatus shown in the drawing comprises a wet heat treatment chamber 1 for performing primary untwisting of a cloth under conditions of normal atmospheric pressure, the chamber being fitted with a pair of endless net conveyors, 2 and 2', provided one above the other so as to form a gap a therebetween serving as a cloth passage. A plurality of jet pipes 31' 31t and 32, 32' are provided alternately above and below the cloth passage along the length thereof such that jets of fluid, such as of hot water or a mixture of water and air can be directed into the cloth passage under high pressure through the adjacent conveyor run.Water catch tanks 4, and 42 are provided in the lower part of the wet heat treatment chamber 1, reservoirs of water Si and 52 respectively being stored therein. The catch tanks 41 and 42 are respectively fitted with steam jet pipes 6, and 62 to allow jets of steam under high pressure to be directed thereinto, and with temperature regulators 71 and 72to allow the control of the water temperature therein. The temperature of the water in the tank 41 is controlled to be, for instance, at about 700C, and the temperature of the water in the tank 42 to be at about 850C.Water in the tank 41 is circulated by means of a pump (not shown) to issue through the water jet pipes 31 and 3,' positioned above the catch tank 41 whereas another pump (also not shown) is arranged to circulate water from the tank 42 to the jet pipes 32 and 32 A high pressure wet heat treatment chamber 9 is provided to subject the primarily-untwisted cloth to a secondary wet heat treatment at higher temperature than that in the chamber 1.The high pressure wet heat treatment chamber 9 is fitted with a cloth inlet opening 10 and a cloth outlet opening 1 the cloth inlet opening 10 and the cloth outlet opening 11 being fitted respectively with an inlet seal mechanism 12 and an outlet seal mechanism 1 3. These seal mechanisms are provided to allow cloth continuously to be passed into the and out of the chamber 9, without allowing substantial leakage of the pressurised atmosphere within the chamber 9.The inlet seal mechanism 12 comprises a pair of sealing rubber rollers 121 pressed against one another to form a nip through which the cloth 8 may pass, a liquid seal tank 122 provided between the rollers 121 and the interior of the chamber, and a number of squeeze bars 123. The outlet seal mechanism 13 also comprises a pair of sealing rubber rollers 13 pressed against one another to form a nip, and a slow cooling tank 132 provided between the sealing rubber rollers 13, and the chamber interior.

A pair of endless net conveyors 14 and 14' are provided one above the other in the high pressure wet heat treatment chamber 9, such that a gap b is formed therebetween, which gap serves as a cloth passage. A plurality of water jet pipes 1 5 and 15' are provided alternately above and below the passage defined by the gap b along the length thereof, such that jets of hot water may issue therefrom into the cloth passage, by passing through the adjacent conveyor run. A water catch tank 1 6 is provided below the lower net conveyor 14', and water collecting in the tank 1 6 is maintained at a temperature of for instance, 1 200 to 1400C by steam issuing through a jet pipe 17.

Water collecting in the tank 1 6 is circulated to the nozzles 1 5 and 15' by means of a pump (not shown). A further steam jet pipe is provided to allow heating of the interior of the chamber 9.

After the cloth leaves the chamber 9, the cloth is passed through a cloth washing device 19, wherein the cloth is washed under conditions of substantially no tension.

Continuous untwisting of a cloth using the apparatus described above is done as follows. At first, the temperatures of the water in the water catch tanks 4r, 42 and 1 6 are kept respectively at about 700, 850 and 1 300C, and the temperatures of the water in the liquid sealing tank 122 and the slow cooling tank 132 are controlled respectively to about 1000 and 500C.

A cloth 8 is supplied to the cloth passage defined by the gap a formed between the two net conveyors 2 and 2' in the wet heat treatment chamber 1, the interior of the chamber being at normal atmospheric pressure. The cloth is transported continuously along the passage in accordance with the operation of the two net conveyors 2 and 2', in the directions of the arrows. As the cloth is advanced, jets of hot water at a temperature of about 700C issue from the water jet pipes 31 and 3,' and the force thereof causes the cloth to take up a zig-zag configuration. The cloth thus follows a snake-like path under conditions of substantially no tension while receiving strong beating and crumpling forces due to the jet pressure of the hot water, and this causes the cloth to swell as well as the yarns constituting the cloth to be untwisted. As the cloth approaches the outlet from the passage, jets of hot water atabout 850C are directed at the cloth from the water jet pipes 32 and 32', and this causes further swelling of the cloth and untwisting of the yarns.

The primarily-untwisted cloth, on leaving the wet heat treatment chamber 1 is then transferred continuously to the high pressure wet heat treatment chamber 9. There, the cloth is passed along the gap b formed between the two net conveyors 14 and 14' and again follows a snakelike path because of the pressure of the jets of hot water at a temperature of about 1300C issuing from the water jet pipes 15 and 15'. This action is similar to that occurring in the chamber 1, but takes place in the chamber 9 under conditions of super-atmospheric pressure and elevated temperature (i.e. above the boiling point of water), with a high humidity. In this way, swelling and untwisting of the cloth is completed and the cloth is effectively crimped to give excellent soft and bulky feel.

The cloth thus untwisted and crimped is passed through the slow cooling tank 132 and leaves the chamber 9 on being passed between the rollers 131 whereafter the cloth is washed by being passed through the cloth washing device 19.

As will be appreciated from the foregoing, in this embodiment of the invention, jets of hot water are directed at a cloth which is being passed continuously through the gap formed between a pair of endless net conveyors provided with two adjacent runs parallel, the jets being alternately on the two sides of the cloth. The temperature of the water jets is raised stepwise from about 700 to 1 500C, and in the described embodiment in two stages, one stage being over the temperature range from about 700 to about 1 000C in a wet heat treatment chamber under the normal atmospheric pressure, and the other stage being over the temperature range from about 1000 to 1 300C in another wet heat treatment chamber under elevated pressure. The cloth goes through the gap in a snake-like state while receiving strong beating and crumpling forces, and this causes the cloth to become swollen, untwisted and crimped effectively, to give a product having fine crimps uniformly all over the cloth. Moreover, since the treatment is done on a continuous basis and in a relatively short time, it is quite suitable for mass production.

Claims

1. A method for continuously untwisting a cloth, comprising passing the cloth along a cloth passage defined by the gap between two adjacent runs of two endless net conveyors respectively arranged one above the other with said runs spaced and substantially parallel, and directing jets of hot liquid at the cloth being passed along the passage alternately from the two sides of the passage thereby causing the cloth to follow a zigzag path as the cloth is advanced along the passage, the temperature of the hot liquid jets being increased stepwise from a temperature below the boiling point of water to a temperature thereabove along the length of the passage, whereby the jets subject the cloth to beating and crumpling forces which swell, untwist and crimp the cloth.

2. A method as claimed in claim 1, in which the temperature of the liquid jets is raised stepwise from substantially 700 to substantially 1 50 C.

3. A method as claimed in claim 1 or claim 2 in which the cloth is advanced along a cloth passage divided into two sections, the jets of hot liquid being directed at the cloth also being correspondingly divided into two stages, the temperature of the jets in the first stage lying in the range of from 700 to 1000C and the temperature of the jets in the second stage lying in the range of from 100 to 1300C.

4. A method as claimed in claim 3, in which the first section of the cloth passage is defined by a pair of net conveyors disposed within a first chamber the internal pressure of which is maintained at normal atmospheric and the second section of which passage is defined by another pair of net conveyors disposed within a second chamber the internal pressure of which is maintained at a super-atmospheric value.

5. A method as claimed in any of the preceding claims in which the hot liquid jetted at the cloth is water.

6. A method for continuously untwisting a cloth substantially as hereinbefore described with reference to the accompanying drawing.

7. Apparatus for the continuous untwisting of cloth, which apparatus comprises a first wet heat treatment chamber the interior of which is arranged to be at normal atmospheric pressure and a second wet heat treatment chamber the interior of which is arranged to be at a superatmospheric temperature, pressure and humidity, each chamber having provided therein a pair of endless net conveyors arranged one above the other with the adjacent runs of the two conveyors respectively spaced apart and parallel thereby to define a gap serving as a cloth passage, a plurality of liquid jet pipes disposed alternately above and below the cloth passage to direct jets of hot liquid into the cloth passage through the adjacent conveyor run, and supply means to supply liquid under pressure to the jet pipes which means is arranged to increase stepwise the temperature of the jetted liquid.

8. Apparatus as claimed in claim 7, wherein catch tanks are disposed within both treatment chambers to catch liquid issuing from the jet pipes, the supply means being arranged to recirculate the liquid collecting in the catch tanks.

9. Apparatus as claimed in claim 7 or in claim 8, wherein the supply means supplies liquid to the liquid jet pipes in the first treatment chamber at temperatures in the range of from 700 to 1 000C and to the liquid jet pipes in the second treatment chamber at temperatures in the range of from 1000 to 1300C.

10. Apparatus for the continuous untwisting of cloth substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.