GB2486795A

GB2486795A - Supplying thermal energy to a working element and/or cover element of a flat card or roller card

Info

Publication number: GB2486795A
Application number: GB1121733.8A
Authority: GB
Inventors: Christoph Leinders
Original assignee: Truetzschler GmbH and Co KG
Current assignee: Truetzschler GmbH and Co KG
Priority date: 2010-12-21
Filing date: 2011-12-16
Publication date: 2012-06-27
Anticipated expiration: 2031-12-16
Also published as: GB2486795B; BRPI1106971A2; DE102010055290A1; CH704294A2; GB2486795A8; CN102560750B; BRPI1106971B1; ITMI20111792A1; GB201121733D0; CH704294B1; BRPI1106971B8; CN102560750A

Abstract

Apparatus on a flat card or roller card comprises at least one working element 14 and/or cover element arranged opposite and spaced apart from a clothed roll 4 and extending over the width of the roll. The element has an elongate carrier member comprising a foot and a back, the foot facing towards the roll absorbs operating heat and the back facing away from the roll is in contact with ambient air. To allow adjustment of the working element and/or cover element to different fibre materials and operating circumstances or conditions and to enable the carding nip to be constant, thermal energy is supplied to the back preferably to provide a largely homogeneous temperature distribution having a very small or no temperature gradient in the carrier member. The working element may comprise a fixed card or a revolving flat assembly. In the case of a revolving flat assembly the thermal energy may be supplied by a heating zone which makes brushing contact with the backs of several flats and is preferably confined to the flat entry region. The heating zone may comprise one or more blankets 27 with which a temperature profile may be established over the working width to counteract different temperature gradients

Description

Apparatus on a flat card or roller card in which there is at least one working element and/or cover element The invention relates to an apparatus on a flat card or roller card in which at least one working element and/or cover element is arranged opposite and spaced apart from a clothed roll and extends over the entire width of the roll.

Working elements and/or cover elements of flat cards or roller cards may typically have an elongate carrier member comprising a foot part and a back part, wherein the foot part facing towards the roll absorbs operating heat and the back part facing away from the roll is in contact with ambient air.

In modern high performance carding machines, heating of tho components and the associated change in the spacing of the components plays an increasingly important role.

The same is also true of the spacing between cylinder and flat bar. In order to be able to achieve good quality at a maximum production rate, that spacing must be kept as constant as possible. The continual increase in the production rates of new generations of carding machine also results, however, in more significant differences between the carding nip set when the machine is cold and the carding nip in the warm state. Furthermore, in the case of an individual flat bar a special situation applies in that the flat bar is not permanently involved in the carding process and accordingly continually cycles between heating and cooling. As a result, in turn, a temperature gradient develops between the clothing side of the flat bar (warm) and its back (cold) . It is precisely this temperature gradient that is responsible for the bar's becoming deformed (towards the cylinder) In carding machines of current design there are utilised as carding elements for the carding process flats having flexible clothings (revolving flats) and/or fixed carding elements having all-steel clothings, the actual clothings being held by high-precision carrier components.

It is customary nowadays to use extruded aluminium profiles as carrier components. Such profiles have numerous advantages, such as, for example, low weight, high rigidity, etc., but additionally have the disadvan-tage that when heated on one side, as is the case during carding, they become deformed towards the heated side. The taller the component, the greater its rigidity but also its deformation under the action of heat. Such deformation results in a non-constant carding nip, which in turn leads to a non-optimum technological carding rosult.

Nowadays the carrier profiles for carding elements are in the form of extruded aluminium profiles closed on all sides. The heat arising during the carding process is dissipated to the outside to a great extent by way of the carding elements. The temperature gradient within the profile cross-section necessary for that purpose results in deformation of the carding element. The greater that gradient, the greater also the deformation.

The heating, however, not only leads to thermal expansion over the entire working width of the carding machine but also has the result that temperature gradients develop across the various forms of the different components of the carding machine. For example, the surface of the cylinder can reach a temperature of 45CC. A carding element located opposite the cylinder will also reach approximately that temperature on the cylinder clothing side, whereas on the side of the carding element facing away from the cylinder, which on account of its construction (as a result of the working width and the precision of the elements) has a back several centimetres in height, the temperature will reach a significantly lower value (for example 28CC) . The difference in temperature over a carding element can accordingly amount to several degrees Celsius. The size of that temperature difference is dependent upon the nature of the element (structure, material), the carding work performed (rotational speed, production rate) and the spacing of the element from the roll.

That temperature gradient causes the elements to sag over the width of the carding machine. As a result of such sagging, the carding nip in the centre becomes narrower than at the outside, resulting in a non-uniform carding nip which widens towards the outside. This leads to a reduction in carding guality and/or inferior untangling of neps. This can also lead to "lateral fly" of the fibres, that is to say fibres collect and even become deposited in the edge region, especially outside the working width.

Those effects are seen in a carding machine having a working width of 1 metre, but increase as the working width increases, for example when the working width is greater than 1 metre, for example 1.2 metres and more. The variations that result from the above-mentioned effect cannot be disregarded here, but are rather a problem for the overall carding quality of the carding machine. The probiem of thermal sagging comes in addition to the mechanical sagging which increases as the working width increases.

Because fixed carding elements and revolving flat bars become very hot during operation of the carding machine, the extruded aluminium profiles of the fixed carding elements or revolving flat bars act, on their outer sides (the sides facing away from the cylinder), as cooling bodies which dissipate their heat by free convection to the surrounding air. As a result, a temp-erature gradient develops within the extruded profile. The side facing towards the cylinder is warmer and therefore expands to a greater extent than does the side facing towards the outside, so that the fixed carding element or the revolving flat bar bends towards the cylinder. That bending (and also the expansion of the cylinder) has the resuit that the carding nip in the centre of the machine becomes narrower and accordingly the web becomes more uneven and the quality deteriorates. In addition, lateral fly can be generated.

Wa 2004/106602 A discloses an element for a carding machine which can come into contact with the fibre material at least on one side, the element having on that side a concave curve over the working width of the carding machine. For that purpose, the working side is machined or aligned so as to produce a concave shape. The element can be a cover element or casing element, a carding segment, a flatr a revolving flat bar, a blade possibly with an extraction device, a guide element or a working element. A disadvantage is that when the machine is in the cold state a concave curve is produced which is preset to be the same for all operating states. Adjustment to the different amounts of heat generated during the processing of different fibre materials, for example cotton and/or synthetic fibres, is not possible.

It is an aim of the invention to provide an apparatus of the kind described at the beginning which avoids or mitigates the mentioned disadvantages, which especially allows adjustment of the working element and/or functional element to different fibre materials and operating circumstances or conditions, and which enables the carding nip to be constant.

The invention provides an apparatus on a flat card or roller card in which at least one working element and/or cover element is arranged opposite and spaced apart from a clothed roll and extends over the entire width of the roll, which element has an elongate carrier member comprising a foot part and a back part, wherein the foot part facing towards the roll absorbs operating heat and the back part facing away from the roll is in contact with ambient air, wherein thermal energy is supplied to the back part.

As a result of the measures taken according to the invention, the working element, for example a flat bar, is suppiied, by way of its back, with the same thermal energy as that produced by the carding on its clothing side. As a resuit, the temperature gradient in the flat is eliminated or at least reduced.

In the case of a revolving card top, advantageously, the temperature gradient is eliminated or at least reduced by means of a heating device at the flat entry point, the flat bar being supplied, by way of its back, with the same heating power as that produced by the carding on its clothing side. Preferably, the heating zone is confined to a short region at the flat entry point. This is sufficient to hold back slightly the thermally induced deformation of the flat bar for its passage over the cylinder, without at the same time impairing the flat's cooling effect on the cylinder. Preferably, the heating of the back of the flat is effected by means of a heating mat along which the flats brush, so that the transfer of heat is effected as efficiently as possible and is targeted on the surface to be heated.

Preferably, the thermal energy is supplied in such a way as to provide a substantially homogeneous temperature distribution. The thermal energy is preferably supplied in such a way that there is either a very small, or substantially no, temperature gradient in the carrier member.

Advantageously, the back part is suppliable with largely the same amount of thermal energy as that absorbed by the foot part as a result of the operating heat.

Advantageously, an electrical heating device can be utilised. By way of example, a heating mat or the like can be utilised. In another illustrative embodiment, an inductive heating device can be utilised.

In certain embodiments, the working element may be a fixed carding element. Instead or as well, a revolving flat assembly having revolving flat bars comprising a flat foot and a flat back may be provided, the working element being a revolving flat bar. Advantageously, the heating zone extends over several flat backs in the region of the flat entry point. Advantageously, the flat backs make brushing contact along the heating mat or the like. In one embodiment, the front flat guide roller is able to transfer thermal energy to the flat backs.

Advantageously, the carrier member is an extruded hollow aluminium profile. Advantageously, the working width is more than 1000mm, for example more than 1200mm.

Advantageously, on the outwardly directed face of the back part the outer walls of the back part are provided, at least in part, with thermal insulation.

In certain embodiments there is present as a working element a revolving flat bar in accordance with the invention. In certain embodiments there is present a revolving flat assembly for a carding machine comprising one or more revolving flat bars according to the invention. In yet other embodiments, there is present as a working element in a carding machine a fixed carding element according to the invention.

It is preferred that thermal energy is supplied in such a way as to produce a temperature profile over the working width in the revolving flat bar, fixed carding element or the like.

The invention also provides an apparatus on a flat card or roller card in which at least one working element and/or cover element is arranged opposite and spaced apart from a clothed roll and extends over the entire width of the roll, which element has an elongate carrier member comprising a foot part and a back part, wherein the foot part facing towards the roll absorbs operating heat and the back part facing away from the roll is in contact with ambient air, wherein thermal energy is supplied to the back part in such a way as to provide a largely homo-geneous temperature distribution having a very small temperature gradient or no temperature gradient in the carrier member.

Certain illustrative embodiments of the invention are described in greater detail below with reference to the accompanying drawings, in which: Fig. 1 is a diagrammatic side view of a carding machine having an apparatus according to the invention; Fig. 2 shows flat bars of the revolving flat top of the carding machine of Fig. 1, with a detail of a slideway, of a setting bend (flexible bend) having a side screen and of the cylinder, and also shows the carding nip between the clothings of the flat bars and the cylinder clothing; Fig. 3 is a side view, partly in section, of a fixed carding element and a part of a side screen, showing the spacing between the carding segment clothing and the cylinder clothing; and Fig. 4 is a diagrammatic side view of a revolving flat assembly having an apparatus according to the invention.

With reference to Fig. 1, a carding machine, for example a flat card IC 07, made by Irützschler GmbH & Co. KG of Mönchengladbach, Germany, has a feed roll 1, feed table 2, lickers-in 3a, 3b, 3c, cylinder 4, doffer 5, stripper roll 6, nip rolls 7, 8, web guide element 9, web funnel 10, delivery rolls 11, 12, revolving flat top 13 with flat guide rollers 13a, 13b and flat bars 14, can 15 and coiler 16. Ihe directions of rotation of the rolls are indicated by curved arrows. Reference letter M denotes the centre point (axis) of the cylinder 4. Reference numeral 4a denotes the clothing and reference numeral 4b denotes the direction of rotation of the cylinder 4. Reference letter B denotes the direction of rotation of the revolving flat top 13 in the carding position and reference letter C denotes the return transport direction of the flat bars 14, with reference numerals 30', 30'' denoting functional elements and reference numerals 13a and 13b denoting flat guide rollers. The arrow A denotes the working direction.

With reference to Fig. 2, on each side of the carding machine there is provided a setting bend 17 (flexible bend) which is integrated integrally in the associated side screen 19. The setting bend 17 has a convex outer surface 17a and an underside 17b. On top of the setting bend 17 there is a slideway 20, for example made of low-friction plastics material, which has a convex outer surfaco 20a and a concavo inner surfaco 20b. The concavo inner surface 20b rests on top of the convex outer surface 17a and is able to slide thereon in the direction of arrows D, E. Each flat bar 14 consists of a back part 14a and a flat foot 14b. Each flat bar 14 has, at each of its two ends, a flat head, each of which comprises two steel pins 14k, 142. Those portions of the steel pins 14, 142 that project beyond the end faces of the flat foot 14b slide on the convex outer surface 20a of the slideway 20 in the direction of the arrow B. A clothing 18 is attached to the lower face of the flat foot 14b.

Reference numeral 21 denotes the circle of tips of the flat clothings 18. The cylinder 4 has on its circumference a cylinder clothing 4a, for example a sawtooth clothing.

The tooth height of the sawteeth is, for example, h = 2 mm. Reference numeral 22 denotes the circle of tips of the cylinder clothing 4a. The spacing (carding nip) -10 -between the circle of tips 21 and the circle of tips 22 is denoted by reference letter a and is, for example, 3/1000". The spacing between the convex outer surface 20a and the circle of tips 22 is denoted by reference letter b. The spacing between the convex outer surface 20a and the circle of tips 21 is denoted by reference letter c.

The radius of the convex outer surface 20a is denoted by reference letter r3 and the radius of the circle of tips 22 is denoted by reference letter r. The radii r1 and r3 intersect at the centre point M of the cylinder 4.

Reference numeral 19 denotes the side screen. The flat bars 14 are extruded hollow profiles made of aluminium having an internal cavity 14c.

In the illustrative embodiment of Figure 3, on each side of the carding machine there is mounted, laterally on the machine frame (not shown), an approximately semi-circular rigid side screen 18, on the outer side of which, in the region of the periphery, there is concentrically mounted an arcuate rigid bearing element 19 having a convex outer surface 19' as supporting surface and an underside 19'' . The apparatus according to the invention comprises at least one fixed carding element 23 which has at its two ends bearing surfaces which rest on the convex outer surface 19' of the bearing element 19 (for example extension bend) . At the lower face 24b (foot part) of the carrier 24 (carrier member) of the fixed carding element 23 there are mounted clothing backs 25, 252 having respective clothings 261, 262 (carding clothings) Reference numeral 21 denotes the circle of tips of the clothings 261, 262. The cylinder 4 has a cylinder clothing 4a, for example saw-tooth clothing, around its circumference. Reference numeral 22 denotes the circle of -11 -tips of the cylinder clothing 4a. The spacing between the circle of tips 21 and the circle of tips 22 is indicated by reference letter a and is, for example, 0.20 mm. The spacing between the convex outer surface 19' and the circle of tips 22 is indicated by reference letter b. The radius of the convex outer surface 19' is indicated by reference letter r5 and the radius of the circle of tips 22 is indicated by reference letter r2. The radii r5 and r2 intersect at the centre point II of the cylinder 4. The carding segment 23 according to Figure 3 consists of a carrier 24 and two clothing strips 27k, 272 each of which comprises a clothing back 25k, 252 with respective clothings 26k, 262. The clothing strips 27, 272 (carding elements) are arranged one after the other in the direction of rotation (arrow 4b) of the cylinder 4, the clothings 26k, 262 (lengths of sawtooth wire) and the clothing 4a of the cylinder 4 being located opposite one another. The carrier 24 consists of an aluminium alloy and is extruded. The clothing backs 251, 252 are attached to the carrier 24 by means of screws 31a, 31b, respectively.

The bulk of the carrier 24 -seen in the direction of the width b -is mounted tangentially with respect to the cylinder 4. The length (not shown) of the carrier 24 is, for example, 1290 mm. Thermal energy may be supplied to the back part of the carrier 24, for example using a suitable heating device (not shown) In the embodiment of Figure 4, in a revolving flat assembly 13 (see Fig. 1) heating of the back part 14a is effected by means of an electrical heating mat 27 along which some of the revolving flat bars 14 make brushing contact. The heating zone is confined to a short region at the flat entry point (that is to say in the region of the -12 -flat guide roller 13b) . As a result, the thermally induced deformation of the flat bar 14 is held back slightly for its passage over the cylinder 4, without the cooling effect of the flat (the non-heated flat bars 14) on the cylinder 4 being impaired at the same time.

According to the invention, heating is effected primarily from the back (back part 14a) of the flat bar 14. Using a heating device, for example one or more heating blankets 27, it is possible to produce a temperature profile over the working width (not shown) of the machine (carding machine) in order to counteract different temperature gradients. The length of the flat bar is, for example, 1290 mm.

Claims

-13 -Claims 1. An apparatus on a flat card or roller card in which at least one working element and/or cover element is arranged opposite and spaced apart from a clothed roll and extends over the entire width of the roll, which element has an elongate carrier member comprising a foot part and a back part, wherein the foot part facing towards the roll absorbs operating heat and the back part facing away from the roll is in contact with ambient air, wherein thermal energy is supplied to the back part.
2. An apparatus according to claim 1, wherein the thermal energy is supplied in such a way as to provide substantially homogeneous temperature distribution.
3. An apparatus according to claim 1 or claim 2, wherein the thermal energy is supplied in such a way that there is either a very small, or substantially no, temperature gradient in the carrier member.
4. An apparatus according to any one of claims 1 to 3, wherein the back part is suppliable with largely the same amount of thermal energy as that absorbed by the foot part as a result of the operating heat.
5. An apparatus according to any one of claims 1 to 4 further comprising a heating device for supplying said thermal energy.
6. An apparatus according to claim 5, wherein the heating device is an electrical heating device.
7. An apparatus according to claim 5 or claim 6, wherein the heating device is a heating mat.
8. An apparatus according to any one of claims 5 to 7, wherein the heating device is an inductive heating device.
9. An apparatus according to any one of claims 1 to 8, -14 -wherein a said working element is a fixed carding element.
10. An apparatus according to any one of claims 1 to 9, wherein the apparatus includes a revolving flat assembly having revolving flat bars comprising a flat foot and a flat back, and a said working element is a revolving flat bar.
11. An apparatus according to claim 10, wherein the thermal energy is supplied in a heating zone that extends over several flat backs in the region of the flat entry point.
12. An apparatus according to claim 11, wherein the heating zone comprises a heating mat and the flat backs make brushing contact along the heating mat.
13. An apparatus according to any one of claims 10 to 12, wherein a front flat guide roller of the revolving flat assembly is able to transfer thermal energy to the flat backs.
14. An apparatus according to any one of claims 1 to 13, wherein the carrier member is an extruded hollow aluminium profile.
15. An apparatus according to any one of claims 1 to 14, wherein the working width of the flat card or roller card is more than 1000 mm.
16. An apparatus according to any one of claims 1 to 15, wherein on their outwardly directed faces the outer walls of the back part are provided, at least in part, with thermal insulation.
17. An apparatus according to any one of claims 1 to 16, wherein thermal energy is supplied in such a way as to produce a temperature profile over the working width in the working element and/or cover element.
18. A revolving flat bar for a carding machine, -15 -comprising an apparatus according to any one of claims 1 to 17.
19. A revolving flat assembly for a carding machine, comprising an apparatus according to any one of claims 1 to 17.
20. A fixed carding element for a carding machine, comprising an apparatus according to any one of claims 1 to 17.
21. A working element for a flat card or roller card substantially as described herein with reference to and as illustrated by any of Figs. 1 to 4.