TAKER-IN PRE-CARDER AND PRE-BLENDER

Abstract: There is disclosed a revolving flat carding machine, and a method of operation thereof, which comprises a main cylinder (11) having cylinder wires (12), a main taker-in roller (23) having card wire clothing with wire ends (23a), and an auxiliary taker-in roller (24) having wire ends (24a) and arranged adjacent to the main taker-in roller (23) to have working co-operation with the latter and to co-operate with the main cylinder (11), in which the auxiliary roller (24) is circumferentially spaced from the main taker-in roller (23) with respect to the outer periphery (22) of the main cylinder and in a direction opposed to the direction of rotation A of the main cylinder, and has a working function with the main taker-in roller (23) and rotating in the same direction B in order to disentangle any unduly large fibre tuft or agglomeration of the main taker-in roller (23) which involves transfer of at least part of such an agglomeration to the auxiliary roller and then conveyance by the auxiliary roller to the main cylinder (11) which strips such material from the auxiliary roller and thereby transfers such material to the main cylinder (11).

Description: TAKER-IN PRE-CARDER AND PRE-BLENDER This invention relates to an improved taker-in assembly for a revolving flat carding machine, to function as a taker-in pre-carder and pre-blender. As is well known, a taker-in roller (also known as "licker-in") is mounted adjacent to the outer periphery of a revolving cylinder, and feeds the fibres of the lap. fleece or batt to the wires on the cylinder, which then conveys the fibres to a revolving flat assembly arranged above the cylinder to co-operate with an upper arc of the cylinder periphery. The flat card assembly comprises an endless series of flats or tops which are interconnected by chain links and which are guided to move widthwise i.e. perpendicular to their lengths, along an arcuate working path of co-operation with the upper arc of movement of the outer periphery of the cylinder, and are then withdrawn so as to carry out a return arcuate path of travel before recommencing the arcuate working path. The fibres therefore undergo a co-operation of carding action of the cylinder wires and the wires on the revolving flats, followed by subsequent removal of the carded fibres from the cylinder by the usual doffer arrangement which is c i rcu ferential ly spaced from the flat bar assembly in the direction of rotation of the cylinder. The normal function of a taker-in roller of a revolving flat carding machine is for its card wire clothing to pull at the fringe of a layer of cotton fibres which emerges from the grip of the usual feed roller which co-operates with the taker-in roller. The load of fibres which the taker-in pulls away and holds by its wire surface consists of a mixture of tufts, fibre entanglements, agglomerations and loose fibres. This load is then cleaned (stripped) from the surface of the taker-in by the wires of the cylinder over the usual arc of co-operation between the cylinder and the taker-in. Since the normal load on a taker-in therefore usually has an irregular distribution of fibre groups of very different sizes and states, and following transfer of this irregular load to the cylinder and onward conveyance to the revolving flats assembly, this is bound to have an adverse effect on the "cylinder-flat " interaction. This is a known problem with taker-in rollers, and one known solution proposes the positioning of first and second transfer rollers between the taker-in and the cylinder, the first of which strips the fibres from the taker-in. and the second of which strips the fibres from the first transfer roller and then allows the fibres to be stripped from it by the cylinder. Each stripping action takes place from one roller to another by reason of progressively increased roller surface speed, before the fibres reach the main cylinder. However, in practice this known proposal does not operate satisfactorily, because the nature of the stripping action which takes place is such that the fibres merely transfer from one roller surface to the next, and therefore large tufts or fibre agglomerations are not disentangled. It has also been proposed to place a small roller into the top co-operation arc between the taker-in and the cylinder, and which has a worker function with the cylinder and a stripping function with the taker-in. While this small roller is able to reduce the size of any fibre agglomera ions which are placed onto the cylinder surface, it has no redistribution effect and also presses any agglomerations present into the cylinder wires. Moreover, any fibres which are inevitably retained by the small worker roller (due to its working engagement with the cylinder wires) are subsequently stripped by the taker-in which carries these fibres back to join the on going feed cycle of the card. The present invention therefore permits a conventional revolving flat carding machine to be provided with an improved taker-in assembly which in one aspect seeks to achieve the size of fibre tufts or agglomerations: to provide improved distribution of these onto the cylinder surface, and to provide additional means for improved fibre individual isation function of the carding process: and in a further aspect the invention provides an improved method of carding employing an improved taker-in assembly According to one aspect of the invention there is provided a revolving flat carding machine comprising: a main cylinder having cylinder wires on its outer periphery with the wire ends pointing in the direction of rotation of the cylinder, and a taker-in assembly arranged to co-operate with the outer periphery of the main cylinder, said taker-in assembly comprising: a main taker-in roller having card wire clothing with the wire ends pointing in the direction of rotation of the roller which is opposite to the direction of rotation of the main cylinder such that the outer peripheries of the roller and of the cylinder move in the same general linear direction in the region of co-operation therebetween so as to effect stripping of fibres from the taker-in roller by the wires of the main cylinder: and. an auxiliary taker-in roller with its wire ends pointing in the direction of rotation of the roller and arranged adjacent to the main taker-in roller to have working co-operation with the latter and to co-operate with the main cylinder, said auxiliary roller being circumferential ly spaced from the main taker-in roller with respect to the outer periphery of the main cylinder and in a direction opposed to the direction of rotation of the main cylinder, and the auxiliary roller being arranged to have a working function with the main taker-in roller and rotating in the same direction in order to disentangle any large fibre tuft or agglomeration on the main taker-in roller and which usually will involve transfer of at least part of such an agglomeration to the auxiliary roller, and the auxiliary roller also having a stripping function with the main cylinder in order to transfer any such part of an ag lomeration thereto. Thus, a revolving flat carding machine according to the invention has improved operation of the taker-in assembly, in that any large tufts or large agglomerations borne on part of the outer periphery of the main taker-in roller are bound to undergo a working co-operation with the auxiliary roller before such part of the outer periphery comes into co-operation with the main cylinder, and such material is therefore partly reduced in size and / or partly disentangled, and with some of the material remaining on the main taker-in roller for subsequent transfer to the main cylinder and with the remainder being transferred to the auxiliary roller before such part also is brought into co-operation with the main cylinder upstream of the material transferred from the main taker-in roller. The co-operation between the main taker-in roller and the auxiliary roller therefore is such as to partly disentangle any large tufts or agglomerations and also to divide such material into separate parts which are subsequently desposited and spaced apart on the periphery of the main cylinder. It should be understood that the auxiliary roller of the takei—in assembly is a minimum requirement of a revolving flat card according to the invention, and that it may be desirable to have one or more additional auxiliary roller arranged to co-operate with the first mentioned auxiliary roller in similar manner to the co-operation between the main roller and the first mentioned auxiliary roller. The additional auxiliary roller is still further spaced circumferential ly of the outer periphery of the main cylinder in a direction opposed to the direction of peripheral movement of the main cylinder, and therefore any part of unduly large tuft material withdrawn from the first mentioned auxiliary roller and transferred to the additional auxiliary roller is eventually transferred to the outer periphery of the main cylinder at a still further circumferential spacing. This therefore gives still further improvement in the distribution of divided-up portions of large fibre tufts or ag lomerations. The invention is particularly applicable to a revolving flat short-staple card, when processing cotton though it should be understood that the invention is also applicable to revolving flat cards when processing other materials, such as polyester, viscose and acrylic fibres. In the carding of cotton with existing machines, as an example, cleaning efficiencies typically of the order of. say. 90% may be obtained to form a sliver by removing as much as possible "trash" and other undesired material from the original supplied material, thus a residual content of about 10% of undesired material will still be present in the carded sliver. However, initial experimental work carried out with two auxiliary rollers in the taker-in assembly i.e. a main auxiliary roller and an additional auxiliary roller, have yielded a reduction in the residual content of undesired material from 10% to 8% i.e. a 20% improvement, in sliver cleanliness: the initial experiment also showed a substantial reduction in yarn neppinesε. The application of the invention is equally advantageous because the dispersal and redistribution of the broken down particles of fibre agglomeration results in a thorough blending and mixing of the fibres, that is increasingly required. Thus carded mixtures of cotton with man made fibres, become thereby more homogenous. Fibres dyed in batches to different colours will yield a yarn of more uniform colour. The invention also provides a method of carding a fibrous lap to form a carded web using a revolving flat carding machine having a main cylinder rotating in one direction, a taker-in roller assembly arranged adjacent to the outer periphery of the cylinder to receive a fibre lap from a feed arrangement and to transfer the fibres to the wires of the cylinder, a revolving flat assembly arranged above the cylinder to co-operate with an upper arc of the cylinder periphery to form the fibres into a carded web. and a doffer arrangement to remove the carded web from the periphery of the cylinder, in which the taker-in assembly includes a taker-in roller which rotates in an opposite direction to the rotation of cylinder and has wire ends which point in its direction so that the wires of the main cylinder can strip fibres from the taker-in roller at the region where the outer peripheries move closely adjacent to each other in the same general linear direction; characterised in that the taker-in assembly also includes an auxiliary taker-in roller having its wire ends pointing in the direction of rotation of the roller and arranged adjacent to the main taker-in roller to have working co-operation with the latter and to co-operate with the main cylinder and said auxiliary roller being circumferentially spaced from the main taker-in roller with respect to the outer periphery of the main cylinder and in a direction opposed to the direction of rotation of the main cylinder, and comprising the following steps: feeding a fibrous lap from the feed arrangement to the main taker-in roller: transferring part of this fibrous lap to the wires of the main cylinder by stripping of the fibres from the taker-in roller by said wires: carrying out a working function of the auxiliary roller with the main taker-in roller in order to disentangle any large fibre tuft or agglomeration of the fibrous lap on the main taker-in roller and transferring at least part of such agglomeration to the auxiliary roller; and. conveying the agglomeration on the auxiliary roller to the main cylinder where it undergoes a stripping function with the main cylinder in order to transfer any such part of the agglomeration thereto. The invention will now be described in detail, by way of example only, with reference to the accompanying drawings in wh i ch : Figure 1 is a schematic side view of a typical construction of revolving flat cotton carding machine to which the invention may be applied; and. Figure 2 is a schematic and enlarged illustration of a novel taker-in assembly for use in an embodiment of revolving flat carding machine according to the invention. Referring first to Figure 1 of the drawings, description will be made of a typical design of a revolving flat carding machine to which the invention may be applied. The carding machine 10 is shown in Figure 1 and comprises a main cylinder 11 having saw tooth type carding wire 12 on its outer periphery, and the ends of which point in the direction of rotation A of cylinder 11. A taker-in assembly 13 is arranged to co-operate with the outer periphery of the main cylinder 11 in order to effect transfer of fibres from a lap, delivered to the taker-in assembly 13 via a usual feed roller and feed plate: the fibres transferred to the cylinder 11 are then conveyed onward in the direction of the arrow to undergo carding treatment along an upper arc of movement of the cylinder 11 in co-operation with the revolving flat assembly 14. The revolving flat assembly 14 is arranged above the cylinder 11 to co-operate with the upper arcuate movement of the cylinder periphery, and comprises an endless series of flats 15 which are interconnected by chain links and which are guided to move widthwise i.e. perpendicular to their lengths, along an arcuate working path of co¬ operation 16 with the outer periphery of the cylinder 11. and are then withdrawn from engagement and after cleaning carry out a return path of travel 17 before recommencing the arcuate working path of movement 16. The fibres undergo a joint carding action by the cylinder wires 12 and the card clothing wires 18 on the flats 15. and the carded fibres are then subsequently removed by a usual doffer arrangement 19 which is ci rcumferential ly spaced from the flat bar assembly 14 in the direction of rotation of cylinder 11. As can be seen in Figure 1. the taker-in assembly comprises a single taker-in roller 20 which pulls at the fringe of a layer of cotton fibres (lap) which emerges from the grip of feed roller and feed plate 21. and then allows these fibres to be stripped from its surface by the wires 12 of the cylinder 11. It is quite a frequent occurence for the load borne by the taker-in roller 20 to have an irregular distribution of fibre groups of very different size and states, and with some of the fibres being present in unduly large fibre tufts or agglomerations. This irregular load is then transferred to the cylinder 11 and conveyed onwardly to the flats assembly 14, and can have an adverse affect on the "cylinder-flat" interaction (carding action) with such an irregular load. The embodiment of taker-in assembly which will now be described with reference to Figure 2 is an improved pre- carder and pre-blender which can be incorporated in a revolving flat carding machine, and is of improved construction so as to reduce the size of any large fibre tufts or agglomerations, and can also provide improved distribution of such material onto the outer periphery of the cylinder. Referring now to Figure 2. a portion 22 of the outer periphery of main cylinder 11 is shown, with a main taker- in (licker-in) roller 23 being positioned to co-operate with outer periphery 22 of the cylinder 11. and having wire ends 23a pointing in the direction of rotation B of roller 23 which is opposite to the direction of rotation A of cylinder 11. The outer peripheries of the roller 23 and of the cylinder 11 therefore move in the same generally linear direction in the region of co-operation therebetween (23.3) so as to effect stripping of fibres from the roller 23 by the wires 12 of the cylinder 11. However, the taker-in assembly includes at least one auxiliary roller 24 which is arranged adjacent to the roller 23 to co-operate both with the latter, and also with the outer periphery 22 of main cylinder 11. It will be seen from Figure 2 that the auxiliary roller 24 is c i rcumferential ly spaced from the main roller 23 with respect to the outer periphery 22 and in a direction opposed to the direction of rotation A of the main cylinder. The auxiliary roller 24 is arranged to have a working function with the taker-in roller 23. and rotates in the same direction B as taker-in roller 23 (and has its wire ends 24a pointing in the direction of rotation B) . in order to disentangle any large fibre tufts or agglomerations on the main roller 23. In the absence of the auxiliary roller 24, such tufts would inevitably be transferred to the outer periphery 22. with the disadvantages referred to above. However, by reason of the presence of the auxiliary roller 24. and its working function with the taker-in roller 23. there will be transfer of at least part of any unduly large fibre tuft from taker-in roller 23 to the auxiliary roller 24. but the auxiliary roller 24 has a stripping function with the main cylinder 11 (similar to the interaction between roller 23 and cylinder 11) in order that such part of an agglomerate transferred to the auxiliary roller can then be transferred to the outer periphery 22 of main cylinder 11. Accordingly, any fibre tufts or agglomerations borne on part of the outer periphery of the taker-in roller 23 can undergo a working co-operation with the auxiliary roller 24 before such part of the outer periphery comes into co-operation with the main cylinder, and therefore such large material is partly reduced in size and / or partly disentangled, and with some of the material remaining on roller 23 for subsequent transfer to the main cylinder 11 and with the remainder being transferred to part of the outer per iphery of auxiliary roller 24, before such part also is brought into co-operation with the mai cylinder, but at a ci rcumferential ly upstream location with respect to roller 23. The co-operation between the taker-in roller 23 and auxiliary roller 24 therefore is such as to partly disentangle any large tufts or agglomerations, and also to divide such material into separate parts which are subsequently spaced apart on the periphery of the main cylinder, thereby simultaneously reducing in size fibre tufts, and also improving the uniformity of distribution of the fibres onto the cylinder periphery. If it should be desired to provide a facility for still further disentanglement and redistribution of any tufts borne on the auxiliary roller 24, an additional auxiliary roller 25 may be provided (having wire ends 25a pointing in the direction of rotation B). which has a working co-operation with roller 24. and a stripping co¬ operation with cylinder 11 which correspond with the working co-operation between roller 24 and roller 23 and the stripping function between roller 24 and cylinder periphery 22. It will be seen from Figure 2 that rollers 23. 24 and 25 all rotate in the same direction B. which is opposed to the direction of rotation A of cylinder 11, and reference numerals 1. 2 and 3. applied to each of the rollers, shows the stations about their outer peripheries at which carding actions take place. After initial carding at station 1. the fibres 26 on the taker-in roller 23 move to station 2 at which a working function takes place with roller 24. and reduced size fibre tufts 27 are then conveyed onwardly to engage cylinder periphery 22 at station 3, whereas some portion of the fibre tufts 26 are withdrawn and conveyed onwardly as smaller fibre tufts 28 by roller 24 towards its station 2 where it undergoes a further carding via working co-operation with additional auxiliary roller 25. and still further reduced size fibre tufts 29 are conveyed onwardly to station 3 of roller 24 where transfer is effected to the cylinder periphery 22. and it will be noted that this is ci rcumferential ly upstream of the transfer from roller 23 to periphery 22. Still further reduced size fibre tufts 30 are then conveyed via rotation of additional auxiliary roller 25 to co-operation with cylinder periphery 22. The nature of the engagement with the wires 12 of cylinder periphery 22 is such as to effect virtually 100% removal of the fibres, so that the rollers 23, 24. 25 then move in an empty state to renewed engagement with their co¬ operating rollers. A typical diameter of main cylinder 11 might be 40 inch, with rotation at 510rpm. whereas roller 23 may be 10 inch diameter and rollers 24 and 25 may be 7 inch diameter. The taker-in roller 23 may rotate at approximately 750 rpm, whereas rollers 24 and 25 may Rotate virtually at any speed. Experimental work carried out with a taker-in assembly as shown in Figure 2 has shown that cleaning efficiency can be improved say from 90 to 92%, as compared with existing machines of the type shown in Figure 1. Thus, e.g. existing machines typically can reduce the original content of undesirable material from the lap fed to the card to a residual content in the sliver of about 10%, whereas the arrangement shown in Figure 2 can reduce the residual content to about 8% or less, which represents about a 20% improvement, in cleaning efficiency, and in an improved sliver with a reduction in the undesired impurity content and neps. To conclude, the following advantages are achieved by the assembly shown in Figure 2: all rollers 23. 24 and 25. after having been stripped by main cylinder 11. are practically empty of fibres: the fibres fed to the taker-in roller 23 are transferred onto the main cylinder 11 in steps: as these fibres arrive on the main cylinder periphery 22 by a stripping action, they lie on the surface of the cylinder wires and are therefore fully exposed for the subsequent arresting function of the flat wires provided by the card clothing on the flats of assembly 14. It is a known phenomenon that the more of the fibres are arrested (retained) by the flats, the more effective are the cylinder wires in combing and thus individualising fibre agglomerations removing neps and setting trash particles free, thus rendering the carding process more efficient: one of any number of auxiliary rollers may be employed, arranged upstream of main roller 23 with respect to the rotation of main cylinder 11: the carding and distributing effect of the rollers can be controlled by their smaller or larger diameters, their individual speeds, the size of setting gaps between the rollers as well as their wire clothing. The choice of these alternative control means is wide and the selection is within the experience of carding engineers: the centrifugal force of the rollers can be taken advantage of to throw out unwanted short fibres, in addition to fluff, trash and dust particles from the cotton. These can be collected and separated from the usual taker-in waste, or alternatively the rollers can be enclosed by grids and sheet metal underscreens.

Claims: CLA I MS 1. A revolving flat carding machine comprising: a main cylinder (11) having cylinder wires (12) on its outer periphery with the wire ends pointing in the direction of rotation A of the cylinder, and a taker-in assembly arranged to co-operate with the outer periphery of the main cylinder, said taker-in assembly comprising: a main taker-in roller (23) having card wire clothing with wire ends (23a) pointing in the direction of rotation B of the roller which is opposite to the direction of rotation A of the main cylinder (11) such that the outer peripheries of the roller (23) and of the cylinder (11) move in the same general linear direction in the region of co-operation therebetween so as to effect stripping of fibres from the taker-in roller (23) by the wires (12) of the main cylinder (11); and, an auxiliary taker-in roller (24) with its wire ends (24a) pointing in the direction of rotation B of the roller (24) and arranged adjacent to the main taker-in roller (23) to have working co-operation with the latter and to co¬ operate with the main cylinder (11) . said auxiliary roller being circumferentially spaced from the main taker-in roller (23) with respect to the outer periphery (22) of the main cylinder and in a direction opposed to the direction of rotation A of the main cylinder, and the auxiliary roller (24) being arranged to have a working function with the main taker-in roller (23) and rotating in the same direction B in order to disentangle any large fibre tuft or agglomeration on the main taker-in roller (23) and which usually will involve transfer of at least part of such an agglomeration to the auxiliary roller, and the auxiliary roller (24) also having a stripping function with the main cylinder (11) in order to transfer any such part of an agglomeration thereto. 2. A carding machine according to Claim 1. including one or more additional auxiliary roller (25) arranged to co-operate with the first mentioned auxiliary roller (24), said additional auxiliary roller (25) being rotatable ir, the same direction of rotation B as the taker-in roller (23) and first mentioned auxiliary roller (24) so as to co¬ operate with the auxiliary roller (24) and with the main cylinder (11) in similar manner to the co-operation between the auxiliary roller (24) and the taker-in roller (23) and the main cylinder (11). 3. A carding machine according to Claim 1 or 2. in which the taker-in roller (23), auxiliary roller (24) and additional auxiliary roller (25) have progressively smaller diameter. 4. A method of carding a fibrous lap to form a carded web using a revolving flat carding machine (10) having a main cylinder (11) rotating in one direction A. a taker-in roller assembly arranged adjacent to the outer periphery (22) of the cylinder (11) to receive a fibre lap from a feed arrangement (21) and to transfer the fibres to the wires (12) of the cylinder, a revolving flat assembly (14) arranged above the cylinder (11) to co-operate with an upper arc of the cylinder periphery (22) to form the fibres into a carded web, and a doffer arrangement (19) to remove the carded web from the periphery of the cylinder, in which the taker-in assembly includes a taker-in roller (23) which rotates in an opposite- direction B to the rotation A of cylinder (11) and has wire ends (23a) which point in direction B so that the wires (12) of the main cylinder (11) can strip fibres from the taker-in roller (23) at the region where the outer peripheries move closely adjacent to each other in the same general linear direction; characterised in that the taker-in assembly also includes an auxiliary taker-in roller (24) having its wire ends (24a) pointing in the direction of rotation B of the roller (24) and arranged adjacent to the main taker-in roller (23) to have working co-operation with the latter and to co-operate with the main cylinder ( 11 ) and said auxiliary roller being c i rcumferent ia 1 ly spaced from the main taker-in roller (23) with respect to the outer periphery (22) of the main cylinder and in a direction opposed to the direction of rotation A of the main cylinder, and comprising the following steps: feeding a fibrous lap from the feed arrangement (21 ) to the main taker-in roller (23) ; transferring part of this fibrous lap to the wires (12) of the main cylinder (11 ) by stripping of the fibres from the taker-in roller (23) by said wires (12) ; carrying out a working function of the auxiliary roller (24) with the main taker-in roller (23) in order to disentangle any unduly large fibre tuft or agglomeration of the fibrous lap on the main taker-in roller and transferring at least part of such agglomeration to the auxiliary roller (24) and, conveying the agglomeration on the auxiliary roller (24) to the main cylinder (11) where it undergoes a stripping function with the main cylinder in order to transfer any such part of the agglomeration thereto. 5. A method according to Claim 4, in which the taker- in assembly includes one or more additional auxiliary roller (25) arranged to co-operate with the first mentioned auxiliary roller (24) , comprising the steps of rotating said additional auxiliary roller (25) in the same direction of rotation B as the taker-in roller (23) and the first mentioned auxiliary roller (24) , so as to co-operate with the auxiliary roller (24) and with the main cylinder (11) . so as to disentangle any large fibre tuft or agglomeration on the auxiliary roller (24) to be transferred to the additional auxiliary roller (25) . which then conveys this material to the main cylinder (11 ) which effects a stripping function on the additional auxiliary roller (25) to transfer such material to the wires (12) of the main cylinder (11) .

Inventors: VARGA ANDRE, VARGA, ANDRE
Applicants: CARDING SPEC CANADA, CARDING SPECIALISTS (CANADA) LIMITED
Application year: 1992
Main classification: D01G15
IPC codes: D01G15