GB2356643A

GB2356643A - Imparting stretch to woven fabric

Info

Publication number: GB2356643A
Application number: GB0028512A
Authority: GB
Inventors: David Weisfeld; Neil Weisfeld
Original assignee: Bandwise Reliant Ltd
Current assignee: Bandwise Reliant Ltd
Priority date: 1999-11-23
Filing date: 2000-11-23
Publication date: 2001-05-30
Anticipated expiration: 2020-11-23
Also published as: GB2356643B; GB0028512D0; GB9927504D0

Description

2356643 Woven-Fabric Treatment This invention relates to woven-fabric

treatment, and is concerned in particular with methods and apparatus for imparting resilience in the form of "stretch" (otherwise referred to as "give" or "ease") to woven fabric.

Methods and apparatus for imparting stretch to woven fabric are known from EP-A-0705356. This discloses a two stage process in which the fabric is first submitted to heat and pressure in a manner to close up strands of the weave and impart stretch to it semi -permanently. In a second stage, the fabric is laminated with an interlining having inherent stretch to give a greater degree of permanence to the imparted stretch.

In the first stage of the process described in EP-A-0705356, a rubberised conveyor belt carries the fabric (which may be in continuous strip form fed from a reel, or as successively- fed strip elements) into a nip between a heated roller and the belt. The application of pressure and heat to the fabric between the roller and belt, closes up the weave in the direction of travel of the belt and imparts stretch to it in that direction.

It is an object of the present invention is to provide a method and apparatus of improved form for imparting stretch to woven fabric.

According to one aspect of the present invention there is provided a method for imparting stretch to woven fabric wherein the fabric is fed progressive ly through a nip between two rolling surfaces, at least a first of the surfaces being heated, and the second surface having resilience for closing up the weave in the feed-direction under the application of heat and pressure to the fabric in passing through the nip, and wherein contact of the 2 fabric with the second surface is broken as the fabric leaves the nip.

According to another aspect of the present invention there is provided apparatus for imparting stretch to woven fabric, including a nip between two rolling surfaces, means for driving one or both of the rolling surfaces to draw fabric fed into the nip therethrough, means for heating at least a first of the surfaces, the second surface having resilience for closing up the weave in the feed-direction under the application of heat and pressure to the fabric in passing through the nip, and the arrangement being such that contact of the fabric with the second surface is broken as the fabric leaves the nip.

It has been found advantageous in the context of providing significant stretch, for contact of the fabric with the second surface in particular, to be broken as soon as possible after the nip.

The first surface of the method and apparatus of the invention as specified above, may be the surface of a cylindrical roller and in these circumstances may be grooved axially of the roller for enhancing its frictional engagement with the fabric; the roller may be motor-driven and in these circumstances the second surface may be driven through contact within the nip.

The second surface of the method and apparatus of the invention as specified above, may be provided in the form of an endless belt that runs round a pair of spaced rollers. In this case, the nip may be formed between said first surface and the belt at a first of the pair of rollers. Force may be applied via said first roller for urging the belt hard against said first surface at the nip. More especially, the pair of rollers may be 3 rotatably mounted on a carriage above said first surface, and the carriage may be urged down towards said f irst surface for exerting the force.

A method and apparatus for woven-fabric treatment, according to the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is illustrative of the fabric-treatment apparatus according to the invention, in sectional side elevation; Figure 2 is illustrative of the fabric-treatment apparatus of Figure I in front elevation with parts removed for clarity of representation; Figure 3 shows details of a belt-carrying carriage of the fabric-treatment apparatus of Figure 1, in enlarged side elevation; and Figure 4 is a side-elevation corresponding to that of Figure 3 showing the endless belt and rollers of the apparatus during operation.

Referring to Figures 1 and 3, the apparatus includes a hollow, cylindrical roller 1 of mild-steel that is driven in rotation by an AC motor (not shown). The cylindrical surface 2 of the roller 1, which is finely grooved axially, is heated by electric radiant-heater elements 3 that are mounted to extend lengthwise of the roller I close to the surface 2 and spaced uniformly from one another throughout almost half the circumference of the surface 2 (sixteen elements 3 may be provided, but it may be found adequate to use eight instead). The heater elements 3 serve to maintain the surface 2 at a substantially constant, high temperature.

4 A nip 4 is formed between the surface 2 of the roller 1 and an endless rubberised belt 5. The belt 5 runs round upper and lower cylindrical rollers 6 and 7 respectively that are free running on an elongate carriage 8. The axle 9 of the upper roller 6 is f ixed within the carriage 8 whereas, as shown more clearly in Figure 3, the axle 10 of the roller 7 is slidable lengthwise of the carriage 8 within slotting 11. A pair of springs 12 (not shown in Figure 2) act between the two axles 9 and 10 to urge then apart and tension the belt 5.

The carriage 8 is carried by a pair of angled arms 13 that are mounted on a pivot shaft 14 for swinging the carriage 8 between an operative or engaged condition (as shown in full line in Figure 1) and an inoperative or withdrawn condition (as indicated by dashed line in Figure 1). swinging of the carriage 8 f rom one to the other of these conditions is effected under control exercised via a pair of pneumatic cylinders 15 that are coupled to the arms 13. Actuation of the cylinders 15 swings the carriage 8 down from its withdrawn condition into its engaged condition in which the tensioned belt 5 is urged down hard onto the surface 2 of the roller 1 forming the nip 4 between them under the roller 6.

Referring now also to Figure 4, drive applied to rotate the roller I when the carriage 8 is in the engaged condition, is transmitted to the belt 5 to rotate it on its free-running rollers 6 and 7. The sense of rotation of the roller 1 (clockwise in Figure 4) is that required to draw fabric presented from a feed-table 16 (Figure 1) progressively into and through the nip 4.

The nip 4 is formed under the upper, fixed roller 6 just ahead of where the belt 5 leaves the roller 6. within the nip 4, therefore, the fabric is subjected to the pressure exerted downwardly through the thickness of the rubberised belt 5 by the roller 6 urged down via the arms 13 by the pneumatic cylinders 15. This pressure applied to the fabric in the presence of the heat from the surf ace 2 on one side and the hot belt 5 on the other side within the nip 4, closes up the weave of the f abric in the f eed-direction to impart stretch to it in that direction. The direct surface-heating of the hollow roller 1 by the heaters 3 ensures that the surface 2 and the belt 5 heated from it, are maintained consistently at substantially the same constant temperature as one another either side of the fabric within the nip 4 throughout operation.

It has been found advantageous for contact of the fabric with the rubberised belt 5 to be broken immediately the fabric leaves the nip 4. This is achieved principally in the present apparatus by the location of the carriage 8 above the heated roller-surface 2 so that the treated fabric leaving the nip 4 follows round on the roller 1 to drop quickly away down into an exit chute 17. However, the breaking of contact between the belt 5 and the fabric is enhanced by the lifting or arching of the belt 5 away from the roller 1 that has been found to take place immediately following the nip 4 as the belt 5 leaves the roller 6.

The lifting of the tensioned belt 5, illustrated in the region of location 18 of Figure 4, results from relaxation of the rubberised material of the belt 5 following the intense compaction that occurs as the belt 5 is drawn on the roller 1 through the tight nip 4 under the roller 6. It is significant in this regard that the axle 9 of the roller 6 is f ixed on the carriage 8, and that it is the lower roller 7 rather than the roller 6 that is acted on by the springs 12 in tensioning the belt 5. These two features allow development of the lifting at location 18 of the belt 5 and significant 6 consequential limitation of the circumferential length of contact of the belt 5 with the fabric and/or roller 1. The contact is confined to the nip 4.

The fabric pressed hard between the hot belt 5 and the hot roller 1 within the nip 4 effectively adheres to the compacted belt 5 so that the weave of the fabric closes up in the feed-direction. The lifting of the belt 5 that occurs at location 18 just after the nip 4, brings about an advantageous distinct and early break of contact between the fabric as the belt 5 relaxes from the compaction. In the latter respect it has been found possible using the method and apparatus described by way of example above on woven-wool fabric, to achieve a stretch of sixteen per cent or more.

The exit chute 17 (which may include an anti-static unit) discharges the treated fabric onto the main input-feed table of a laminating machine (not shown) for carrying out the second stage of the process described in EP-A-0705356; in this second stage the fabric is laminated with an interlining. However, it is possible to bond the fabric to a base interlining simultaneously with its passage through the apparatus described above.

In this respect, the fabric and interlining are fed together into the nip 4 to be bonded together by adhesive under the pressure and heat applied within the nip 4, and imparting to both the stretch characteristic. An elasticated interlining can then be added by separate lamination.

7 claims:

1. A method for imparting stretch to woven fabric wherein the fabric is fed progressively through a nip between two rolling surfaces, at least a first of the surfaces being heated, and the second surface having resilience for closing up the weave in the feed-direction under the application of heat and pressure to the fabric in passing through the nip, and wherein contact of the fabric with the second surface is broken as the fabric leaves the nip.

Claims

2. A method according to Claim 1 wherein said first surface is the surface

of a cylindrical roller.

3. A method according to Claim 2 wherein the surface of the roller is grooved axially for enhancing its frictional engagement with the fabric.

4. A method according to Claim 2 or Claim 3 wherein the roller is hollow.

5. A method according to any one of Claims 1 to 4 wherein said first surface is heated by electric radiant heat.

6. A method according to any one of Claims 1 to 5 wherein said second surface is a rubberised surface.

7. A method according to any one of Claims 1 to 6 wherein said second surface is the surface of an endless belt.

S. A method according to Claim 7 wherein the belt runs round a pair of spaced rollers such that the nip is 8 formed between said first surface and the belt at a first of the pair of rollers.

9. A method according to Claim 8 wherein the pair of rollers are urged apart from one another resiliently so as to tension the belt, and force is applied via said first roller to urge the belt hard against said first surface at the nip.

10. A method according to Claim 9 wherein the pair of rollers are rotatably mounted on a carriage with the axis of rotation of said first roller fixed relative to the carriage and that of the second roller displaceable relative to the carriage for tensioning the belt as aforesaid.

11. A method according to Claim 10 wherein the carriage is mounted above said first surface and is urged down towards said first surface for exerting said force.

12. Apparatus for imparting stretch to woven fabric, including a nip between two rolling surfaces, means for driving one or both of the rolling surfaces to draw fabric fed into the nip therethrough, means for heating at least a first of the surfaces, the second surface having resilience for closing up the weave in the feeddirection under the application of heat and pressure to the fabric in passing through the nip, and the arrangement being such that contact of the fabric with the second surface is broken as the fabric leaves the nip.

13. Apparatus according to Claim 1 wherein said first surface is the surface of a cylindrical roller.

9 14. Apparatus according to Claim 13 wherein the surface of the roller is grooved axially for enhancing its frictional engagement with the fabric.

15. Apparatus according to Claim 13 or Claim 14 wherein the roller is hollow.

16. Apparatus according to any one of Claims 13 to 15 wherein a motor is coupled to the roller for driving it in rotation, said second surface being driven through contact within the nip.

17. Apparatus according to any one of Claims 12 to 16 wherein said first surface is heated by electric radiant heater means.

18. Apparatus according to any one of Claims 12 to 17 wherein said second surface is a rubberised surface.

19. Apparatus according to any one of Claims 12 to 18 wherein said second surface is the surface of an endless belt.

20. Apparatus according to Claim 19 wherein the belt runs round a pair of spaced rollers such that the nip is formed between said first surface and the belt at a first of the pair of rollers.

21. Apparatus according to Claim 20 including means for applying force via said first roller for urging the belt hard against said first surface at the nip.

22. Apparatus according to Claim 21 wherein the pair of rollers are rotatably mounted on a carriage above said first surface, and the carriage is urged down towards said first surface for exerting said force.

24. Apparatus according to Claim 22 wherein said first roller is mounted on the carriage with its axis of rotation fixed relative to the carriage, the second roller is mounted on the carriage with its axis of rotation displaceable relative to the carriage, and means is operative to displace the rotational axis of said second roller relative to the carriage for tensioning the belt resiliently.

25. A method for imparting stretch to woven fabric, substantially as hereinbefore described with reference to the accompanying drawings.

26. Apparatus for imparting stretch to woven fabric, substantially as hereinbefore described with reference to the accompanying drawings.