GB2486796A

GB2486796A - Apparatus on a flat card or roller card in which there is arranged at least one working element and/or cover element

Info

Publication number: GB2486796A
Application number: GB1121734.6A
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
Also published as: ITMI20111793A1; BRPI1106972A2; CN102534873A; CH704295B1; CN102534873B; BRPI1106972B1; GB201121734D0; CH704295A2; DE102010055291A1

Abstract

In an apparatus on a flat card or roller card in which at least one working element (14, Figure 2) and/or cover element is arranged opposite and spaced apart from a clothed roll (4) and extends over the entire width of the roll, the element has an elongate carrier member. The carrier member comprises a foot part 14b and a back part 14a and the back part is in the form of a hollow body in cross-section. The foot part faces towards the roll and absorbs operating heat and the back part faces away from the roll and is in contact with ambient air. In the interior of the hollow body there is at least one substantially vertically arranged partition wall 14'" which joins the foot part 14b to the back part 14a to provide a largely homogeneous temperature distribution having a very small temperature gradient or no temperature gradient in the carrier member. The thickness of the partition wall preferably decreases in the direction from the foot to the back. The partition wall may consist of a material having a higher thermal conductivity than material of outer walls of the back part. Outer walls 14" may have thermal insulation on their outwardly directed faces.

Description

Apparatus on a flat card or roller card in which there is arranged 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, the back part being in the form of a hollow body in cross-section, 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) Modern flat bars (MC 2006/039829 A) are configured so as to produce in their interior one or more horizontally separated hollow chambers which are "filled" with air (good insulator) . As a result, the flow of heat is confined to the outer webs of the flat bar, which are in turn involved in heat exchange with the environment. This resuits in relatively large differences in temperature between the clothing side and the back of the flat bar.

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 profilos as carrier compononts. Such profilos have numor-ous advantages, such as, for example, low weight, high rigidity, etc., but additionally have the disadvantage 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 resuits in a non-constant carding nip, which in turn leads to a non-optimum technological carding result.

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 2YC) . The difference in temp-erature 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 quality 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 problem 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 flat, 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 a contact with ambient air, wherein the back part is in the form of a hollow body in cross-section and comprises a back wall opposed to said foot part, and wherein, in the interior of the hollow body there is at least one substantially vertically arranged partition wall which joins the foot part to the back wall.

Preferably, the vertically arranged partition wall is arranged in such a way as to provide a largely homogeneous temperature distribution having a very small temperature gradient or no temperature gradient in the carrier member.

As a result of the measure taken according to the invention, the temperature gradient of the flat is minimised by a cross-section that is configured so as to be optimum in terms of heat conduction. This is achieved by ribs arranged vertically in the flat bar, which ribs are decoupled from heat exchange with the environment by the neighbouring hollow chambers ("filled" with air) and accordingly greatly accelerate the heating of the flat back.

Advantageously, the working element is a fixed carding element. Advantageously a revolving flat assembly having revolving flat bars comprising a flat foot and a flat back is provided, wherein the working element is a revolving flat bar. Preferably at least one longitudinal channel extends from one end to the other end of the back part, for example the flat back. Preferably, at least one longitudinal channel is closed on all sides in its wall region.

Advantageously, the partition wall is a rib or the like. Preferably, the at least one partition wall is decoupled from heat exchange with the environment by the neighbouring longitudinal channels (hollow chambers) Preferably, the longitudinal channels are filled with air.

Advantageously, the partition wall is integrated integrally into the carrier member. Preferably, the partition wall is integrally joined to the upper region of the back part.

Advantageously, the width (cross-section) of the partition wall decreases in the direction from the foot part to the back part. Preferably, the wall thickness of the partition wall is greater than the wall thicknesses of the outer walls of the back part.

Advantageously, the carrier member is an extruded aluminium hollow profile.

Advantageously, the width (cross-section) of the partition wall is substantially constant. Preferably, the width of the partition wall is such that an optimum (large) amount of heat flows from the foot part to the back part. Preferably, the partition wall consists of a material having higher thermal conductivity than the material for the outer walls of the back part.

Advantageously, the partition wall is firmly joined to the foot part and the upper region of the back part.

Preferably, at least one partition wall is arranged vertically with respect to the foot part.

Advantageously, the working width of the flat card or roller card is more than 1000 mm, for example more than 1200 mm. The working element including the partition wall advantageously extends across the entire working width.

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

The invention also provides a revolving flat bar for a carding machine, comprising an apparatus according to the invention. Further, the invention provides a revolving flat assembly for a carding machine comprising a plurality of card flat bars according to the invention.

Moreover, the invention provides a fixed carding element for a carding machine, comprising an apparatus according to the invention.

The invention further 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 and the back part is in the form of a hollow body in cross-section, 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, characterised in that in the interior of the hollow body there is at least one substantially vertically arranged partition wall which joins the foot part to the back part in such a way as to provide a largely homogeneous 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 the 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 cross-section through a revolving flat bar (foot part and back part) according to the invention showing a partition wall.

With reference to Fig. 1, a carding machine, for example a flat card TC 07, made by Trützschler 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 l3a, l3b and flat bars 14, can 15 and coiler 16. The directions of rotation of the rolls are indicated by curved arrows. Reference letter N 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 revoiving 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.

In the illustrative embodiment of 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 -10 -outer surface 20a and a concave inner surface 20b. The concave 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 141, 142. Those portions of the steel pins 141, 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) 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 embodiment of Figure 3, on each side of the carding machine there is mounted, laterally on the machine -11 -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) (see Fig. 4) . At the lower face of the carrier 24 (carrier member) of the fixed carding element 23 there are mounted clothing backs 251, 252 having respective clothings 261, 262 (carding clothings) Reference numeral 21 denotes the circle of tips of the clothings 26k, 262. The cylinder 4 has a cylinder clothing 4a, for example saw-tooth clothing, around its circumference. Reference numeral 22 denotes the circle of 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 P4 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 252, 252 with respective clothings 262, 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 -12 -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, 3lb, respectively.

The bulk of the carrier 24 -seen in the direction of the width b -is mounted tangentially with respect to the cylinder 4.

According to Fig. 4, in the interior 14c (which consists of two continuous longitudinally aligned channels 14c2 and 14c2) of the back part 14a of a revolving flat bar 14 there is arranged a vertically arranged partition wall 14''' which joins the foot part 14b integrally with the upper covering region of the back part 14a. The cross-section (width) of the partition wall decreases in the direction from the foot part 14b to tho back part 14a. The partition wall 14''' is located between the two outer walls 14' and 14'' of the back part 14a. The side walls of the longitudinal channels 14c2 and 14c2 are closed on all sides. The respective end faces of the longitudinal channels 14c2 and 14c2 are open. The length (not shown) of the revolving flat bar 14 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 the back part is in the form of a hollow body in cross-section, and comprises a back wall opposed to said foot part, and wherein, in the interior of the hollow body there is at least one substantially vertically arranged partition wall which joins the foot part to the back wall.
2. An apparatus according to claim 1, in which the arrangement of the partition wall between said foot part and said back wall is such that in use there is a substantially homogeneous temperature distribution.
3. An apparatus according to claim 2, in which there is a small or substantially no temperature gradient in the carrier member.
4. An apparatus according to any one of claims 1 to 3, wherein a said working element is a fixed carding element.
5. An apparatus according to any one of claims 1 to 4, wherein a revolving flat assembly having revolving flat bars comprising a flat foot and a flat back is provided, wherein a said working element is a revolving flat bar.
6. An apparatus according to any one of claims 1 to 3, wherein at least one longitudinal channel extends from one end to the other end of the back part.
7. An apparatus according to any one of claims 1 to 6, -14 -wherein a said working element is a card flat comprising a back enclosing at least one channel that extends longitudinally between the ends of the flat.
8. An apparatus according to claim 6 or claim 7, wherein said at least one longitudinal channel is closed on all sides in its wall region.
9. An apparatus according to any one of claims 1 to 8, wherein the partition wall is a rib.
10. An apparatus according to any one of claims 1 to 9, wherein the at least one partition wail is substantially decoupled from heat exchange with the environment by adjacent longitudinal channels.
11. An apparatus according to any one of claims 6 to 8 and 10, wherein the longitudinal channels are filled with air.
12. An apparatus according to any one of claims 1 to 11, wherein the partition wall is integrally formed with the carrier member.
13. An apparatus according to any one of claims 1 to 12, wherein the partition wall is integrally joined to an upper region of the back part.
14. An apparatus according to any one of claims 1 to 13, wherein the thickness of the partition wall decreases in the direction from the foot part to the back part.
15. An apparatus according to any one of claims 1 to 13, wherein the width of the partition wall is substantially constant.
16. An apparatus according to any one of claims 1 to 15, wherein the wall thickness of the partition wall is greater than the wall thicknesses of outer walls of the back part.
17. An apparatus according to any one of claims 1 to 16, -15 -wherein the width of the partition wall is such that an optimally large amount of heat flows from the foot part to the back part.
18. An apparatus according to any one of claims 1 to 17, wherein the partition wall consists of a material having higher thermal conductivity than the material for outer walls of the back part.
19. An apparatus according to any one of claims 1 to 18, wherein the partition wall is firmly joined to the foot part and the upper region of the back part.
20. An apparatus according to any one of claims 1 to 19, wherein the at least one partition wall is arranged vertically with respect to the foot part.
21. An apparatus according to any one of claims 1 to 20, wherein the carrier member is an extruded aluminium hollow profile.
22. An apparatus according to any one of claims 1 to 21, wherein on their outwardly directed faces the outer walls of the back part are provided, at least in part, with thermal insulation.
23. An apparatus according to any one of claims 1 to 22, wherein the working width of the card is more than 1000 mm.
24. A revolving flat bar for a carding machine, comprising an apparatus according to any one of claims 1 to 23.
25. A revolving flat assembly for a carding machine, comprising an apparatus according to any one of claims 1 to 23 including a plurity of card flats.
26. A fixed carding element for a carding machine, comprising an apparatus according to any one of claims 1 to 23.-16 -
27. 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.