GB2221478A

GB2221478A - Fabric decatising machine

Info

Publication number: GB2221478A
Application number: GB8914806A
Authority: GB
Inventors: Sydney Parnell Morris
Original assignee: James Bailey
Current assignee: James Bailey
Priority date: 1988-06-28
Filing date: 1989-06-28
Publication date: 1990-02-07
Anticipated expiration: 2009-06-28
Also published as: GB8914806D0; GB8815344D0; GB2221478B

Abstract

A continuous decatising machine has a heated roller 12 and a cooling roller 14 around which two endless blankets 18, 20 extend to enable a fabric 56 which is being decatised to be entrained therebetween so as to subject the fabric fibres to a heating and plasticising treatment and then to a cooling treatment. The fabric 56 is subjected to a compressive loading exerted thereon by the tension of the blankets 18, 20 and to an additional pressure exerted thereon by the nip defining heating and cooling rollers 12, 14 as the fabric 56 entrained in the blankets 18, 20 passes therebetween to produce a set in the fabric fibres which are then subjected to a thermal shock during passage around the cooling roller 14 to retain the fabric fibres in their set condition. The nip pressure increases the degree of setting of the fabric fibres. The tension on blankets 18, 20 is adjustable. The roller 12 uses steam and compressed air and roller 14 is cooled by suction. The fabric may pass through additional cooling or refrigeration unit. <IMAGE>

Description

An improved decatising machine This invention relates to a decatising machine and more particularly, to a continuous decatising machine.

During the finishing of textile fabrics formed of for example, in whole or in part of natural fibres particularly wool, it is usual to subject the fabric to a process which produces a finish on the fabric. It is of course important for the quality of the finish to be substantially unaffected by subsequent processes such as dyeing or other wet processes.

One known method of producing a finish on the fabric is to pass the fabric through a rotary press which applies pressure to the fabric as it is passed over a heated platen.

A further known method is to use a decatising machine in which a batch or piece of the fabric is wound around a roller in an autoclave to which steam is admitted to heat the fabric and plasticise the fibres. The fabric is then cooled and removed from the autoclave. The autoclave in such a batch decatising machine is sealed during the processing so that the pressure therein can be raised above atmospheric pressure to improve the finish obtained on the fabric.

Although such a batch decatising machine can be used to produce a high quality finish on the fabric it suffers from the disadvantage of being unsuitable for use in a-...~, continuous finishing process.

An alternative method involves the use of a continuous decatising machine in which the fabric under compression is passed around a heated roller to plasticise the fibres and is then passed around a cooling roller providing a thermal shock to retain the fibres in their set condition thereby producing the desired fabric finish.

Whilst this enables the finishing process to be a continuous process, the degree of setting obtained often makes it necessary to utilise additional processes1 such as a rotary press, to produce the quality of finish required.

The object of this invention is to provide a continuous decatising machine which enables an improved standard of finish on the fabric to be achieved.

According to one aspect of this invention, a continuous decatising machine for producing a finish on a fabric which is continuously passed therethrough comprises a first stage for heating the fabric under compression to plasticise and set the fabric fibres, a second stage for cooling the fabric to provide a thermal shock and to thereby retain the fibres in the desired set condition, and a pressure application stage interposed between the first and second stages to subject the fabric fibres in their plasticised condition to additional pressure to increase the degree of setting thereof.

Preferably, the first stage comprises a heated roller around which the fabric passes in order to heat and to plasticise the fibres thereof.

Preferably, also, the heated roller is hollow and the curved surface thereof is provided with a plurality of apertures through which steam supplied to the interior of the roller is emitted to heat and plasticise the fibres of the fabric being processed.

Additional heating means is, preferably, provided within the roller to increase the temperature of the steam applied to the fabric and may comprise one or more heating pipes through which steam passes,the pipes being disposed within the roller adjacent to at least part of the internal peripheral surface thereof, Preferably, the second stage comprises a cooling roller around which the fabric passes so as to be subjected to a thermal shock to retain the fibres in their set condition.

Preferably, also, the cooling roller is hollow and the curved surface thereof is provided with a plurality of apertures through which air is drawn to cool the roller and the fabric passing therearound.

Two endless blankets are, preferably, provided which during part of their path through the machine both pass in superposed relationship around the heating roller and the cooling roller before each following their own separate paths round associated guide rollers.

Preferably, the fabric to be processed is entrained between the two blankets, carried thereby around the heating roller and the cooling roller, and compressed by the tension of the blankets during the passage around the rollers.

Preferably, also, the tension of the blankets is adjustable to vary the compressive force applied to the fabric being processed.

The heating roller and/or the cooling roller are, preferably, driven to drive the blankets and the fabric through the machine.

Preferably, the pressure application stage of the machine, comprises means for applying a nip pressure to the fabric between the first and the second stages.

Preferably, also, the means for applying a nip pressure comprises cooling roller adjustment means for adjusting the position of the cooling roller relative to the heating roller to adjust the nip pressure applied to the fabric and the blankets passing therebetween.

Additional cooling or refrigeration means is, preferably, provided through which the fabric passes after passing around the cooling roller and prior to delivery from the machine to subject the fabric to an additional thermal shock to facilitate retention of the fibres of the fabric in their set condition and to also facilitate removal of moisture from the fabric created during the passage around the cooling roller.

According to another aspect of this invention, a method of decatising fabric to produce a finish thereon comprises heating the fabric to plasticise the fibres thereof whilst compressing the fabric to initiate setting of the fibres, applying a nip pressure to the fabric to further set the fibres, and cooling the fabric under the compressive load to provide a thermal shock for retaining the fibres in their set condition.

Preferably, the fabric is subjected to additional cooling or refrigeration to subject the fabric to an additional thermal shock and remove moisture therefrom.

A preferred embodiment of the invention will now be described by way of example only, with reference to the accompanying drawing, which is a diagrammatic side elevation of a continuous decatising machine with parts omitted for the sake of clarity.

Referring now to the drawing, a continuous decatising machine for use in à continuous finishing process of a fabric formed of natural fibres, particularly wool fibres, comprises two parallel spaced-apart side frames 10 having a heating roller 12, and a cooling roller 14, extending transversely therebetween, each roller being rotatably mounted in bearings for rotation about the longitudinal axis thereof. The heating roller 12 and the cooling roller 14 are driven by a conventional motor driven chain and sprocket drive assembly (not shown). In certain conditions1 it will be found to be desirable to only drive the heating roller 12 or, alternatively, to only drive the cooling roller 14.

The position of the bearings of the cooling roller 14 on the side frames 10 is adjustable to move the axis of rotation of the cooling roller 14 towards or away from the fixed axis of rotation of the heating roller 12 to vary the "nip pressure" between the rollers 12 and 14.

The heating roller 12 is of a hollow cylindrical construction and the curved surface is provided with a plurality of apertures (not shown) through which steam and compressed air supplied to the interior of the roller is emitted. The supply of compressed air and steam to the roller 12 produces the advantage that the additional volume of compressed air utilised minimises the volume of steam required to achieve the desired conditions.

Each of the apertures is formed by a hollow tubular insert, known as a "nipple", 'secured to the curved surface of the roller and extending a short distance radially inwardly of the curved surface to avoid the condensate which collects within the roller being emitted through the apertures. Condensate removal means (not shown) is provided for removing condensate from the interior of the roller 12.

Heating pipes (not shown) are mounted within the roller 12 and extend longitudinally parallel to the axis of rotation adjacent to the internal surface of the roller. The heating pipes are in a fixed position relative to the frames 10 so that the curved surface of the roller 12 rotates past the pipes which raise the temperature of the steam being emitted through the apertures which are in their immediate vicinity. The pipes extend over an arcuate area of approximately one third of the curved surface of the roller 12 and across the full working width thereof.

A trough 16 is mounted between the side frames 10 beneath the heating roller 12 and extends across the full working width thereof. The sides of the trough 16 extend upwardly to substantially enclose the heating roller 12 therein to guide and retain the stearyl emitted from the roller 12 in the region thereof to improve the heating action. The trough 16 also collects condensate and means are provided for zem.oving the condensate therefrom.

The cooling roller 14 is of a hollow cylindrical construction and the curved surface is provided with a plurality of apertures (not shown) through which air is drawn t extraction means (not shown) into the interior of the roller 14 to provide a cooling effect.

The heating roller 12 is provided with an internal heat shield (not shown) disposed in a fixed position adjacent to the internal surface thereof and extending on each side of the area of contact between the heating roller 12 and the cooling roller 14 to inhibit the direct flow of steam from the heating roller 12 to the cooling rollerl4 and thus improve the efficiency thereof.

The cooling roller 14 is also provided with an internal heat shield (not shown) disposed in a fixed position adjacent to the internal surface thereof on the feed side of the area of contact between the cooling roller 14 and the heating roller 12 to reduce direct heat transfer and improve efficiency.

Two endless blankets 18 and 20 formed of, for example, a polyester material1 are mounted on the rollers 12 and 14 so as to travel for at least part of their path in superposed relationship around the rollers 12 and 14 before following their own separate paths through the machine.

The b'anket 18, which is driven in the direction of the arrow "" by the roller 12, passes around an input roller 22, the rollers 12 and 4, an exit roller 24 and rollers 26, 28, 30, 32, 34, 38, and 38.

The blanket 20, which is driven in the direction of the arrow "o" by the roller 12, also passes around the input roller 22, the rollers 12 and 14, the exit roller 24, and rollers 40, 42, 44, 46, 48, 50, 52, and 54.

The. rollers 28 and 4' are heated to dry the associated e of the blankets 18 and 20 and the position of the rollers 32 and 48 are adjustable to vary the tension of the associated blanket 18 and 20.

An additional heat shield (not shown) is mounted in a fixed position adjacent to the external surface of the cooling roller 14. The heat shield extends from a point close to the point of contact of the cooling roller 14 with the heating roller 12 to a point close to the point of contact of the blankets l8 and 20 with the roller 14 to enclose the portion of the surface of the roller 14 which is not covered by the blankets 18 and 20 so as to again mprove the efficiency thereof.

Fabric 56 to be decatised enters the machine and passes over guide rollers 58, 60, 62, 64, and 66 before being entrained between the blankets 18 and 20 during passage over the input rolle 22. The entrained fabric 56 passes @round the heating roller 12, the cooling roller 4, before passing around the exit roller 24, the rollers 40 and 42, and after disengagement from the blanket 20 around guide rollers 63, 7, 72, 7A, 76 and a pair of delivery rollers 78.

Curved iron in plates 80 and 82 are disposed between the rollers 38 and 38, and 52 and 54 respectively for engag-r, and ironing the surfaces of the blankets 18 and 20 to mantain a smooth surface finish teheron. The leading edge of each ironIng pate 80 and 82 is provided with crush 80 for brushing and straightening the fibres of the blankets 18 and 20 prior to them being ironed smooth by their respective ironing plates 80 and 82.

During passage across the top of the machine, the fabric 56 passes through an additional cooling or refrigeration unit Inot shown) mounted on the top of the frames 10 of the machine.

Moistening means (not shown) is located in the machine for increasing the moisture content of the fabric 56 prior to it commencing its passage around the heating roller 1.2. The moistening means (not shown) consists of either apparatus for directly increasing the moisture content nf the fabric 56 or for indirectly increasing the te moisture content of the fabric 56 by providing apparatus for moistening one or both of the blankets 18 or 20 prior to the fabric 58 being entrained therebetween.

In operation, the fabric SC entrained between the blankets 18 and 20 is compressed by the tension of the blankets 18 and 20 which can be varied by adjustment of the pos iofl of the rollers 32 and 4:3. The entrained fabric 56 is plasticised during the passage around the heating roller 12 and the fibres are set to a required degree by the compressive loading in posed on the fabric by the blankets 18 and 20 and by the "nip pressure" between the heating roller 12 and the cooling roller 14.

A thermal shock is applied to the fabric 56 as it passes around the cooling roller 14 to retain the degree of setting of the fibres which has been obtained for producing the required finish on the fabric 56.

A further thermal shock is applied to the fabric 56 as it passes through the additional cooling or refrigeration unit tnot shown) which also removes moisture from the fabric 56 prior to delivery from the machine.

The application of a nip pressure to the fabric 56 whilst it is it 5 plasticised condition increases the degree if setting obtained and improves the finish of the fabric.

It will be appreciated that other features of the maschine described above also enable an improved quality of finish to be obtained on the fabric, making the machine which i@ the subject of this invention particularly suitable for use in the continuous decatising of high quality fabrics formed of natural fibres such as wool, or synthetic fibres, or a blend of natural and synthetic fibres.

Claims

What we claim is:

1. A continuous decatising machine for producing a finish on a fabric which is continuously passed therethrough comprising a first stage for heating the fabric under compression to plasticise and set the fabric fibres, a second stage for cooling the fabric to provide a thermal shock and to thereby retain the fibres in the desired set condition, and a pressure application stage interposed between the first and second stages to subject the fabric fibres in their plasticised condition to additional pressure to increase the degree of setting thereof.

2. A machine according to Claim 1, wherein the first stage comprises a heated roller around which the fabric passes in order to heat and to plasticise the fibres thereof.

3. A machine according to Claim 2, wherein the heated roller is hollow and the curved surface thereof is provided with a plurality of apertures through which steam supplied to the interior of the roller is emitted to heat and plasticise the fibres of the fabric being processed.

4. A machine according to Claim 3, wherein additional heating means is provided within the roller to increase the temperature of the steam applied to the fabric.

5. A machine according to Claim 4, wherein the additional heating means comprises one or more heating pipes through which steam passes, the pipes being disposed within the roller adjacent to at least part of the internal peripheral surface thereof.

6. A machine according to any one of the preceding claims, wherein the second stage comprises a cooling roller around which the fabric passes so as to be subjected to a thermal shock to retain the fibres in their set condition.

7. A machine according to Claim 6, wherein the cooling roller is hollow and the curved surface thereof is provided with a plurality of apertures through which air is drawn to cool the roller and the fabric passing therearound.

8. A machine according to any one of Claims 2 to 5 and Claim 6 or Claim 7, wherein two endless blankets are provided which during part of their path through the machine both pass in superposed relationship around the heating roller and the cooling roller before each following their own separatepaths round associated guide rollers.

9. A machine according to Clam 8, wherein the fabric to be processed is entrained between the two blankets, carried thereby around the heating roller and the cooling roller, and compressed by the tension of the blankets during the passage around the rollers.

10. A machine according to Claim 9, wherein the tension of the blankets is adjustable to vary the compressive force applied to the fabric being processed.

11. A machine according any one of Claims 8 to 10, wherein the heating roller and/or the cooling-roller are driven to drive the blankets and the fabric through the machine.

12. A machine according to any one of the preceding claims1 wherein the pressure application stage of the machine, comprises means for applying a nip pressure to the fabric between the first and the second stages.

13. A machine according to Claim 12 and any one of Claims 2 to 5 and any one of Claims 6 to 11, wherein the means for applying a nip pressure comprises cooling roller adjustment means for adjusting the position of the cooling roller relative to the heating roller to adjust the nip pressure applied to the fabric and the blankets passing therebetween.

14. A machine according to any one of the preceding claims and Claim 6, wherein additional cooling or refrigeration means is provided through which the fabric passes after passing around the cooling roller and prior to delivery from the machine to subject the fabric to an additional thermal shock to facilitate retention of the fibres of the fabric in their set condition and to also facilitate removal of moisture from the fabric created during the passage around the cooling roller.

15. A method of decatising fabric to produce a finish thereon comprises heating the fabric to plasticise the fibres thereof whilst compressing the fabric to initiate setting of the fibres, applying a nip pressure to the fabric to further set the fibres, and cooling the fabric under the compressive load to provide a thermal shock for retaining the fibres in their set condition.

16. A method according to Claim 15, wherein the fabric is subjected to additional cooling or refrigeration to subject the fabric to an additional thermal shock and remove moisture therefrom.

17. A machine constructed, arranged and adapted to operate substantially as hereinbefore described with reference to, and as illustrated by, the accompanying crawlr.6s.

18. A method of decatising fabric substantially as hereinbefore described.

18. A etod of decatising fabric substantially as hereinbefore described.

D.A.Lister CPA D.A.Lister & Co.

Amendments to the claims have been filed as follows 1. A continuous decatising machine for producing a finish on a fabric which is continuously passed therethrough comprising a first stage for heating the fabric under compression by passing a heating fluid therethrough to plasticise and set the fabric fibres1 a second stage for cooling the fabric to provide a thermal shock and to thereby retain the fibres in the desired set condition, and an intermediate pressure application stage interposed between the first and second stages to subject the fabric fibres in their plasticised condition to the flow of heating fluid passing therethrough directly from the first to the second stage and to the simultaneous application of additional pressure to increase the degree of setting thereof.

2. A machine according to Claim 1, wherein the first stage comprises a heated roller around which the fabric passes in order- to heat and to plasticise the fibres thereof.

5. A machine according to Claim 4, wherein the additional heating means comprises one or more heating pipes through which steam passes1 the pipes being disposed within the roller adjacent to at least part of the internal peripheral surface thereof.

6. A machine according to any one of the preceding claims1 wherein the second stage comprises a cooling roller around which the fabric passes so as to be subjected to a thermal shock to retain the fibres in their set condition.

7. A machine according to Claim 6, wherein the cooling roller is hollow and the curved surface -thereof is provided with a plurality of apertures through which air is drawn to cool the roller and the fabric passing therearound.

9. A machine according- to Claim 8, wherein the fabric to be processed is entrained between the two blankets, carried thereby around the heating roller and the cooling roller, and compressed by the tension of the blankets during the passage around the rollers.

11. A machine according any one of Claims 8 to 1O, wherein the heating roller and/or the cooling roller are driven to drive the blankets and the fabric through the machine.

12. A machine according to any one of the preceding claims, wherein the intermediate pressure application stage of the machine, comprises means for applying a nip pressure to the fabric between the first and the second stages.

14. A machine according to any one of the preceding claims and Claim 6,, wherein additional cooling or refrigeration means is provided through which the fabric passes after passing around the cooling roller and prior to delivery from the machine to subject the fabric to an additional thermal shock to facilitate retention of the fibres of the fabric in their set condition and to also facilitate removal of moisture from the fabric created during the passage around the cooling roller.

15. A method of decatising fabric to produce a finish thereon comprises heating the fabric by passing a heating fluid therethrough to plasticise the fibres thereof whilst compressing the fabric to initiate setting of the fibres, applying a nip pressure to the fabric to further set the fibres whilst passing the heating fluid therethrough, and cooling the fabric under the compressive load to provide a thermal shock for retaining the fibres in their set condition.

16. A method according to Claim 15, wherein .the fabric is subjected to additional cooling or refrigeration to subject the fabric to an additional thermal shock and remove moisture therefrom.

17. A machine constructed, arranged and adapted to operate substantially as hereinbefore described with reference to, and as illustrated by, the accompanying drawings.