GB2043727A

GB2043727A - Compressive shrinkage of textile and paper webs

Info

Publication number: GB2043727A
Application number: GB7908242A
Authority: GB
Original assignee: Hunt and Moscrop Textile Machinery Ltd; Hunt and Moscrop Ltd
Current assignee: Hunt and Moscrop Textile Machinery Ltd; Voith Paper Ltd
Priority date: 1979-03-08
Filing date: 1979-03-08
Publication date: 1980-10-08
Also published as: DE8002058U1; ES8102222A1; IT8047731A0; FR2450769A1; JPS55122069A; ES488118A0; BR8000445A; IT1207087B; NL8000523A; DE3002337A1; SE8001752L; BE881371A; IN152886B; GB2043727B

Abstract

A process for the compaction of dry textile, paper or paper containing man made fibre webs 5 in which the web passes between a driven pressure roller 3 and an adjustable endless belt 1 passing over a pair of rollers 2 one of which is driven so that the speed of the driven roller 2 can be varied relatively to the speed of the pressure roller 3, the position of the two rollers 2 being adjustable relatively to the pressure roller 3 to vary the arc of contact between the pressure roller and the belt from 0 DEG -78 DEG . The roller 3 is mounted on a slide movable by a hydraulic ram 4. The roller 3 and the driven roller 2 are driven by separate variable speed motors (6), (8). <IMAGE>

Description

SPECIFICATION Compressive shrinkage of textile and paper webs This invention relates to a process for compacting a textile web, paper web, a paper web containing man made fibres or eliminate pre-moisterising and after drying.

A known process for compacting is to employ an endless rubber belt running on idler rollers with a pressure roller to form an expanded surface and a contracted surface and mechanically compacting the web by passing it from the expanded surface to the contracted surface between the belt and the pressure roller. When passing from the expanded surface to the contracted surface the surface of the rubber is shortened pushing the web into a compacted state due to the affinity of the web to the rubber. In this process moisture is added by pre-damping, and when processing heavier materials it was necessary to pre-damp and steam. This pre-treatment assisted the mechanical compacting by slightly swelling the fibres, and lubricating the crossings of the warp and weft yarns and the possibility of some natural compaction by relaxation of the tension stresses in the warp direction.The added moisture has to be dryed out of the web and this is normally achieved by tensionless drying on a palmer cylinder dryer after compaction.

In the specification of our prior British Patent Number 913194 we have claimed a shrinking machine in which the back or rear roller is mounted in a block capable of two adjustments in the machine via, a vertical adjustment and a horizontal adjustment to vary the arc of contact of the belt with the driven roller.

In the specification of our prior British Patent Number 1339484 we have claimed that by driving the front belt roller or the back belt roller and the belt and driving the pressure roller at a higher speed than that at which the belt is travelling a greater degree of compaction can be imparted to the textile or paper web.

It has been found under close investigation that various facts were of paramount importance: 1). The length and shape of the arc of contact of the belt with the driven roller.

2). The thinning and distortion of the belt when under pressure from the driving roller.

3). The thinning and distortion of the belt when under pressure and being driving by the driving roller.

4). The controlled percentage of speed variation between the driven pressure roller and the driven belt roller.

5). That the co-efficient of friction between the fabric and the sleeve was reduced when processing a pre-damped web.

6). That the greater the distortion of the belt in the nip area when under pressure and being driven the greater the amount of compaction obtained due to the rubber belt returning to it's original cross section after being released from the nip the reaction of the rubber being in the opposite direction to the travel of the web and therefore the greater the distortion the greater the reaction, and the greater the compaction.

Using a machine constructed as specified in our British Patent Number 1339484 with the horizontal and vertical adjustments as specified in our British Patent Number 913194, it was found that the braking action of driving the belt roller at a slower speed than the pressure roller the distortion at the nip was increased and the reaction of the rubber backwards against the direction of travel of the web was increased providing a more powerful compacting source of energy compared with previous machines.

This extra amount of compaction available could be controlled by varying the amount of braking action from neutral to a realistic maximum. The compaction achieved was also affected by varying the arc of contact of the belt with the driven roller by utilising the vertical and horizontal adjustment of the back blet roller, the degree of variation being from 35"-76" of the arc of contact.

It was then found that by varying the arc of contact by moving the belt in a horizontal direction relative to the driven pressure roller or by moving the driven pressure roller horizontallytothe sleeve the degree of variation in arc of contact to 0 -78 could be increased thus greatly increasing the range (over the previous machine British Patent 91319) as described in the specification of patent application 38170/78 Serial No. 2031040.

By utilizing the greater range of arc of contact together with the extra compacting energy due to the braking action of driving the belt roller at a slower speed than the pressure roller it has been possible to adjust each to give maximum compaction conditions for each type of web being processed and this together with the increased co-efficient of friction of a dry web was enough to enable processing is being carried out without the need to add moisture or steam to the web and consequently this eliminated the need for after drying.

A machine for carrying out the process is illustrated diagrammatically and will be described with reference to the accompanying drawings: Fig. is a diagrammatic side elevation of the machine; Fig. 2 is a detail view showing the maximum arc of contact; Fig. 3 is a detail view showing the minimum arc of contact; Fig. 4 shows a diagrammatic elevation of the drivers for the pressure roller and endless belt.

The machine comprises an endless belt 1 passing around the rollers 2, and 2a the distance between the rollers being adjustable to vary the tension on the belt. One of the rollers 2a is driven.

A driven pressure roller 3 is mounted on a slide, and under hydraulic pressure from a ram 4 is capable of moving vertically relatively to the belt and applying pressure to the belt between the rollers 3 and 2, the amount of pressure being variable. The rollers 2 and 2a are capable of being moved in a horizontal direction to vary the angle of contact between the pressure roller 3 and the belt 1. The web 5 is passed between the pressure roller 3 and the belt 1, and the web may be subjected to a maximum angle of contact of 78" as shown in Fig. 2 or to as low as a minimum angle of 0 as shown in Fig. 3 or any angle between 0 to 78 .

The pressure roller is driven by a variable speed drive motor 6 through a speed reduction gear 7, and the roller 2a over which the endless belt passes is driven by a second variable speed drive motor 8 through a second speed reduction gear 9.

Claims

1. A process for eliminating pre-moisturing and after drying during the compaction of textile, paper, and paper containing man made fibre webs, comprising feeding a dry textile or paper web between a driven pressure roller and an endless belt passing over a pair of rollers, means for adjusting the distance between the pair of roller, means for varying the arc of contact of the web between the pressure roller and the endless belt of 0 to 78 .

2. A process for eliminating pre-moistureing and after drying during the compaction of textile, paper, and paper containing man made fibre webs, as in claim 1, comprising moving the belt horizontally relatively to the driven pressure roller to increase the range of compaction.

3. A process for eliminating pre-moisturing and after drying during the compaction of textile, paper, and paper containing man made fibre webs, as in claim 1, comprising moving the pressure roller horizontally relatively to the belt to increase the range of compaction.

4. A process for eliminating pre-moisturing and after drying during the compaction of textile, paper, and paper containing man made fibre webs, as in claims 1-3, in which the greater the distortion of the belt in the nip area when under pressure and being driven, the greater the amount of compaction obtained due to the rubber belt returning to it's original cross section after being released from the nip, the reaction of the rubber being in the opposite direction to the travel of the web and therefore the greater the distortion the greater the reaction, and the greater the compaction.

5. A fabric web when compacted bythe method of claim 1.

5. A process for eliminating pre-moisturising and after drying during the compaction of textile, paper, and paper containing man made fibre webs as in Claim 1 comprising moving the belt horizontally relative to the driven pressure roller or moving the pressure roller horizontally relative to the belt and driving the belt roller at a controlled slower speed than that of the pressure rollerto increase the range of compaction.

6. A machine for carrying out the process of Claim 1, substantially as described with reference to the accompanying drawings.

7. A fabric web when compacted by the process of Claim 1.

New claims or amendments to claims filed on 7 Aug 1979.

Superseded claims all.

New or amended claims:

1. A method for eliminating pre-moistening and after drying of a web during the compaction of textile paper and paper containing a man made fibre web in a machine in which the web passes between a driven pressure roller and an endless belt passing overtwo rollers mounted in blocks arranged transversally of the machine, and providing a nip between the pressure roller and the belt in a machine as described in the specification of our Patent 913194 comprising movement of both belt rollers horizontally, driving one belt roller at a slower speed than the pressure roller as described in the specification of our Patent No. 1339484 to move the belt rollers horizontally relatively to the pressure rollerto achieve greater reaction of the belt after release from the nip to enable the compaction process to be carried out on a dry web and therefore eliminating after drying.

2. A method for eliminating pre-moistening and after drying during the compaction of textile fibre and paper containing man made fibre webs, comprising passing a dry web between the driven pressure roller and the belt passing over the pair of rollers, means for moving the belt and pressure roller horizontally to vary the arc of contact between the pressure roller and the belt between 0" to 78".

3. A process for eliminating pre-moisturising and after drying during the compaction of textile, paper, and paper containing man made fibre webs as in claim 1 comprising moving the belt horizontally relative to the driven pressure roller or moving the pressure roller horizontally relative to the belt and driving the belt roller at a controlled slower speed than that of the pressure rollerto increase the range of compaction.

4. A method for eliminating pre-moisturising and after drying during the compaction of textile, paper, and paper containing man made fibre webs, substantially as hereinbefore described.