GB2100302A

GB2100302A - Mercerizing textile webs

Info

Publication number: GB2100302A
Application number: GB8207165A
Authority: GB
Original assignee: ROBUR WERKE ZITTAU VEB
Current assignee: ROBUR WERKE ZITTAU VEB
Priority date: 1981-06-15
Filing date: 1982-03-11
Publication date: 1982-12-22
Also published as: NL188238C; IT1148586B; NL188238B; DD158712A3; IT8248612A0; SU1270188A1; NL8200763A; CH639231B; GB2100302B; FR2507636B1; DE3205282C2; CH639231GA3; FR2507636A1; DE3205282A1

Abstract

Textile webs are mercerized by passing the web (25) from one roll pair, consisting of a roll (5) from a top row of rolls and a roll (1) from a bottom row, around a transfer roll (9) to a next roll pair, also consisting of a roll (6) from the top row and a roll (2) from the bottom row. As a result, the web to be treated is squeezed once in an almost horizontal nip, twice in succession in nips of 45 DEG , and then again once in an almost horizontal nip. The rolls (5-8) of the upper row have their axes offset alternately behind and ahead of the axes of the lower rolls (1-4). <IMAGE>

Description

SPECIFICATION Method of and apparatus for mercerizing textile webs This present invention relates to a method and apparatus for mercerizing of textile webs, for example sheets of cotton or mixtures of cotton and other fibres in the broad condition on a chainless mercerizing machine. Such a method and apparatus finds application in the textile finishing industry.

A chainless mercerizing machine may be basically divided into two parts, the so-called mercerizing or impregnating section and the stabilizing or lye removing section. In both parts, the material to be treated must, in order to achieve the desired process effects, be guided absolutely fixed or constrained.

A chainless mercerizing machine is disclosed in German (Dem. Rep.) Patent specification No.

112 741, in which the textile material web passes directly from the surface of one roll to the next. For this purpose two rows of rolls are disposed one above the other. The upper rolls are staggered relative to the lower rolls and arranged above the gaps between the lower rolls. This principle has been adhered to for many decades. Some manufacturers extend the roll arrangement by additional squeezer rolls above the upper rolls, in order to improve the impregnating and dealkalizing effect by appropriate squeezer zones (DD-PS 10 236). In DE-OS 25 44494 there is disclosed a machine which does not depart from this basic principle, although a portion of the alkaline steeping section is displaced into the vertical in order to shorten the machine.

The arrangement of the partly horizontal, partly vertical web guidance has, however, not enjoyed widespread use due to economic and technical reasons, so that the forms of web guidance established by the original concept is still used today.

For this web guidance, a large number of rolls and a substantial machine length with the accompanying high material and production costs are required in relation to the quantity of cloth able to be processed per unit length of the machine, in spite of the reduction in residence times as a consequence of the increased throughput speeds.

Moreover, the substantial length of the machine requires a considerable amount of installation space.

There is accordingly a need for a method and apparatus in which the machine length can be substantially reduced without reducing the web length able to be processed.

According to a first aspect of the present invention there is provided a method of mercerizing a web of textile material, comprising the step of so guiding the web under tension around each of the rolls of a plurality of pairs of upper and lower squeezing rolls arranged with the upper rolls in one row and lower rolls in another row and around transfer rolls between the roll pairs that in the travel direction the web passes around the roll pairs in succession and around a respective one of the transfer rolls during each transfer from one roll pair to the next and is squeezed in a substantially horizontal squeezing zone between the rolls of each pair and in two oblique squeezing zones between each transfer roll and, respectively, a roll of the immediately preceding pair and a roll of the immediately succeeding pair.

In an example of this method, the web to be treated, coming from a roll pair consisting of one roll of an upper and one roll of a lower row of rolls, is guided by means of at least one transfer roll to the next roll pair, consisting of one roll of the upper and one of the lower row of rolls. The material to be treated is squeezed, once in an approximately horizontal squeezing nip, twice thereafter in a nip of approximately 450, and then again once in an approximately horizontal squeezing nip.

Preferably, the web comes from the first roll of the lower row of rolls, passes over a first roll of the upper row of rolls, and before it reaches the second roll of the upper row of rolls, is guided around a first transfer roll. Thereafter it runs over a second roll of the lower row and then via a second transfer roll around a third roll of the lower row, and finally reaching a third roll of the upper row.

This sequence can be continued over further roll pairs and transfer rolls.

According to a second aspect of the present invention there is provided web guide apparatus for use in carrying out the method of the first aspect of the invention, the apparatus comprising a plurality of pairs of upper and lower squeezing rolls arranged with the upper rolls in one row and lower rolls in another row, the upper rolls being mounted to be supported by the lower rolls and being so arranged that their axes in the direction of the rows are offset alternately behind and ahead of the axes of the respectively associated lower rolls.

Preferably, the rolls of the upper row of rolls are disposed resting on the rolls of the lower row and with a slight, positively-negatively alternating central offsetting from these rolls. The rolls of the upper row are preferably somewhat smaller in diameter than the rolls of the lower row. For preference, the centre points of the axes of the individual rolls of the upper row together with the centre points of the axes of the rolls of the lower row are disposed on an at least approximately meandering line as viewed in direction of the sheet travel. Moreover, gaps may be provided between the rolls of the upper and of the lower row of rolls and a transfer roll of substantially smaller diameter than the other rolls can be introduced into each of these gaps.The rolls of the lower row are preferably somewhat wider than those of the upper row and the transfer rolls, are mounted in stationary locations, are driven and are equipped with guide flanges. The rolls of the upper row, by contrast, may be constructed as simple roll tubes without end supports and without their own drives. The upper rolls preferably rest on the rolls of the lower row and on the transfer rolls and can be raised by means of mechanical, hydraulic or pneumatic lifting means.

Expediently, the first and third transfer rolls are mounted in stationary locations and not driven.

The second transfer roll, by contrast, may be constructed as a simple roll tube without end supports and likewise not driven. Instead, it can rest on the rolls of the lower row of rolls and be raised by means of mechanical, hydraulic or pneumatic lifting means. The second transfer roll is preferably coated with a resilient facing.

An example of the method and an embodiment of the apparatus will now be more particularly described with reference to the accompanying drawing, the single figure of which is a schematic side view of an alkaline steeping compartment of a mercerizing machine for textile material webs.

Referring now to the drawing, there is shown the steeping compartment of a mercerizing machine, in which are arranged a lower row of driven rolls 1, 2, 3 and 4. Immediately above and resting on these rolls 1 to 4 are rolls 5, 6, 7 and 8 of an upper row. The rolls 5 to 8 have a positivelynegatively alternating central offset relative to the rolls 1 to 4. Between the individual rolls gaps are provided within each row, in which gaps transfer rolls 9, 10 and 11 are respectively disposed. The transfer rolls 9 and 11, on which the rolls 5 to 8 additionally bear, are stationarily mounted. The transfer roll 10 rests on the rolls 2 and 3 and is therefore not stationarily mounted. The rolls 5 to 8 and also the transfer rolls 9 to 11 do not possess their own drives.They are entrained by the driven rolls 1 to 4 by friction at the squeezing gaps or nips and are thereby coupled together to rotate at the same circumferential speed. The nonstationarily mounted rolls 5 to 8 and also the transfer roll are simple roll tubes without ends or journals and have a resilient facing. The rolls 1 to 4 are broader than the rolls 5 to 8 and the transfer rolls 9 to 11, and are provided at the parts projecting at both ends with guide flanges. The rolls 5 to 8 have a smaller diameter than the rolls 1 to 4. The transfer rolls 9, 10 and 11 in turn have a much smaller diameter than the other rolls. The centrepoints 12,13,14,15,16,17and 180fthe axes of the rolls 1,5,6,2,3,7,8 and 4 respectively constitute, viewed in the direction of travel of a web 25 through the steeping compartment, an approximately meandering line.

The rolls 5 to 8 and the transfer roll 10 can be raised by means of hydraulic lifting devices 20, 21,23,24 and 22, in order to facilitate the puliing-in of the web 25 to be mercerized. Finally, portions of the circumferences of the rolls 1 to 4 dip into a bath of impregnating liquid 26, in the present example caustic lye.

The alkaline steeping compartment illustrated in the drawing shows only a proportion of the total number of rolls, etc., that may be required. A downstream stabilizing and de-alkalizing compartment has the same basic construction with regard to the guidance of the web. The principle of the web guidance is, however, adequately represented by the illustrated section of the steeping compartment.

In use, the textile web 25, coming from a spreader device 27, reaches the roll 1 and wraps around this roll. The web 25 passes directly from the roll 1 to the roll 5 and then runs directly around the transfer roll 9. Thereafter the web 25 passes around the rolls 6 and 2. From the roll 2, the web 25 reaches the next transfer roll 10 and thence the roll 3, to pass then onto the roll 7. The web 25 then runs onto the transfer roll 11 and thence onto the roll 8, etc. The roll pairings 1 and 5,5and9,9and6,6and2,2and 10, lOand3, 3 and 7,7 and 11,11 and 8,8 and 4, etc., each define a squeezing gap in which the web 25 is squeezed. The gaps defined between the rolls of each pair of upper and lower rolls 5/1, 6/2, 7/3 and 8/4 represent substantially horizontal squeezing zones, while the gaps defined between the transfer rolls 9 to 11 and the immediately adjacent ones of the upper and lower rolls represent oblique squeezing zones extending at, for example, 450 to the horizontal.

With web guidance in the manner described, important advantages are achieved for the machine manufacturer and also for the user in the textile finishing industry. For an equivaient web length and at least equal mercerizing effect, the number of rolls and the machine length, amongst other things, may be considerably reduced as compared with the conventional roll arrangement.

Claims

1. A method of mercerizing a web of textile material, comprising the step of so guiding the web under tension around each of the rolls of a plurality of pairs of upper and lower squeezing rolls arranged with the upper rolls in one row and lower rolls in another row and around transfer rolls between the roll pairs that in the travel direction the web passes around the roll pairs in succession and around a respective one of the transfer rolls during each transfer from one roll pair to the next and is squeezed in a substantially horizontal squeezing zone between the rolls of each pair and in two oblique squeezing zones between each transfer roll and, respectively, a roll of the immediately preceding pair and a roll of the immediately succeeding pair.

2. A method as claimed in claim 1, wherein the web is so guided around the rolls that in the travel direction it passes, in order, around the lower roll of a first one of the pairs, the upper roll of the first pair, a first one of the transfer rolls, the upper roll of a second one of the pairs, the lower roll of the second pair and a second one of the transfer rolls.

3. A method as claimed in claim 2, wherein the web is guided to pass around further such roll pairs and transfer rolls in the same order.

4. A method of mercerizing a web of textile material, the method being substantially as hereinbefore described with reference to the accompanying drawing.

5. Web guide apparatus for use in carrying out a method as claimed in claim 1, the apparatus comprising a plurality of pairs of upper and lower squeezing rolls arranged with the upper rolls in one row and lower rolls in another row, the upper rolls being mounted to be supported by the lower rolls and being so arranged that their axes in the direction of the rows are offset alternately behind and ahead of the axes of the respectively associated lower rolls.

6. Apparatus as claimed in claim 5, wherein the upper rolls are of smaller diameter than the lower rolls.

7. Apparatus as claimed in either claim 5 or claim 6, wherein the axes of the upper and lower rolls in the direction of the rows are disposed along a meandering path.

8. Apparatus as claimed in any one of claims 5 to 7, comprising a respective transfer roll arranged between each roll pair and the or each immediately adjacent roll pair, the transfer rolls being of small diameter than the rolls of the roll pairs.

9. Apparatus as claimed in claim 8, wherein the lower rolls are wider than the upper rolls and the transfer rolls and are provided at their ends with guide flanges, the lower rolls being mounted in stationary locations in the apparatus and being drivably coupled to drive means.

10. Apparatus as claimed in either claim 8 or claim 9, wherein each of the upper rolls comprises a tubular roll element resting on the associated lower roll and transfer roll and provided with a resilient facing, the upper rolls being frictionally drivable by a web of textile material guided around the rolls.

11. Apparatus as claimed in claim 10, wherein the upper rolls are connected to and adjustable in height by lifting means.

12. Apparatus as claimed in any one of claims 8 to 11, wherein the first and third ones of the transfer rolls in the direction of the rows are mounted in stationary locations in the apparatus and the second one of the transfer rolls comprises a tubular roll element resting on adjoining ones of the lower rolls and provided with a resilient facing, the transfer rolls being frictionally drivable by a web of textile material guided around the rolls.

13. Apparatus as claimed in claim 11, wherein the second transfer roll is connected to and adjustable in height by lifting means.

14. Apparatus for use in carrying out a method as claimed in claim 1 , the apparatus being substantially as hereinbefore described with reference to the accompanying drawing.