Improvements to carding processes

Abstract

 A method of winding slubbings tightly in a carding process, the method including placing one or more finger guides 1 with its longitudinal axis generally in line with output from a carding machine and immediately before a winding spool 7 of the carding machine, feeding a slubbing 5 to each finger guide from the carding machine, wrapping each slubbing around its finger guide 1 to develop a stress or tension therein and delivering from the finger guide the slubbing on to the surface of a spool 7 or spool drive roller 6 for winding on to the spool 7.

Description

[0001] The present invention relates generally to the manufacture of spun yarns by the woollen system. More particularly the present invention relates to a woollen carding process and the production of denser spools of woollen slubbings or slivers.

[0002] In conventional processing, the raw material or blend of staple fibres is carded with the objects of disentangling the fibres from each other, freeing dirt, vegetable matter and other unmounted contaminants, improving the mixing of fibres, particularly when more than one fibre type is included in the blend, evening out the flow of material to produce a web of fibres as uniform as possible in density and finally splitting the web into parallel ribbons, consolidating those ribbons into slubbings or slivers by rubbing them between two oscillating surfaces, and winding the slubbings into packages suitable for spinning. The raw material may consist of 100% wool or other natural fibre, blends of natural fibres with man-made or synthetic fibres, or 100% synthetic fibres. However, irrespective of the raw material processed such a process is commonly known as the Woollen Process by historical tradition.

[0003] Slubbings are normally wound onto spools, empty spools being creeled on the card relative to a series of guides which ensure that slubbings are wound side-by-side on the spools in an orderly fashion. The spools are creeled on the card such that they rest on driven rollers which in turn drive the spools by frictional contact to effect winding. The winding speed is thus governed by the surface speed of the driven drums which is normally constant.

[0004] In conventional practice several ends of slubbing are wound on to one spool, and a regular transverse oscillation is provided between the spools and slubbing guides such that cheeses of slubbing are wound. The number of cheeses of slubbing wound on to each spool varies according to the gauge of the spinning machine on which the yarn is to be spun,. and is thus governed largely by the count of the yarn. Spools may be wound with as few as six cheeses of slubbing when heavy counts of yarn such as carpet yarns are being spun, or there may be as many as twenty cheeses per spool in fine count spinning.

[0005] The number of cheeses also depends upon the length of the spool, but generally the overall dimensions of a full spool are chosen as an optimum compromise for good ergonomics and economics of the whole process.

[0006] Slubbings are produced and wound on the card as soft - twistless strands having low tensile strength. Some tensile strength is derived from interfibre entanglements and consolidation of the fibre assembly in the rubbing process, and this strength is sufficient to enable winding the slubbings at a low tension draft of about 6% without irregularly stretching the slubbing or in any way reducing its evenness. Thus spools of slubbings tend to be soft with a density in the material of the order of 0.15 gm/cc, depending upon the raw material being processed. This low density of material limits the amount of slubbing which can be wound on a full spool of reasonable and acceptable diameter. Spools of woollen slubbings are handled at the card and again at the spinning frame, and in practice spool related tasks form a high proportion of the total labour reqirement in both carding and spinning. The material capacity of the spool thus has a limiting effect on the economic efficiencies of both the carding process and the spinning process.

[0007] The invention seeks to provide a method and equipment for winding slubbings tightly, thus increasing the density of slubbings on the spool, and increasing the net amount of material wound on the spool without increasing its finished diameter.

[0008] According to the broadest aspect of the present invention there is provided a method of handling slubbings in the woollen process, the method including positioning one or more finger guides in the path of the same number of slubbings, and wrapping a slubbing around each finger guide to thereby create a stress or tension therein before the slubbings are directed for further processing.

[0009] According to one aspect of the present invention there is provided a method of winding slubbings tightly in a carding process, the method including placing one or more finger guides with its longitudinal axis generally in line with output from a carding machine and immediately before a winding spool of the carding machine, feeding a slubbing to each finger guide from the carding machine, wrapping each slubbing around its finger guide to develop a stress or tension therein and delivering from the finger guide the slubbing on to the surface of a spool or spool drive roller for winding on to the spool.

[0010] A further disadvantage of current spool winding practice is apparent when it is desired to break down the spool into separate and individual cheeses of slubbings. This is sometimes practised in order to improve machine efficiency in a spinning process, or in order to accommodate the special requirements of a particular spinning machine. In this case it is known to fit the spool centre with separate, removable sleeves upon which individual cheeses are wound. Such sleeves form centres for the separate cheeses, facilitating their removal from the spool and further providing support for the cheese of slubbing for handling and further processing. Softly wound cheeses at present can be easily deformed and/or damaged in handling an further processing, leading to wastage of material.

[0011] It is an advantage of the of the present invention that it can provide separate cheeses of slubbings of improved firmness and stability as well as increased weight, in order to improve the efficiency of further handling and processing.

[0012] In conventional woollen processing systems it is normal to draft the slubbings as part of the spinning process by drafting means provided for this purpose on the spinning machine. Because of the nature of woollen slubbings, in which there is substantial interfibre entanglement and a high incidence of hooked fibres, drafting is normally limited to a ratio of about 1.5:1. The hooked fibres contribute to the limitation of drafting, because of their orientation in the slubbings. The hooks predominantly trail in the slubbing as it is delivered by the card, but in spinning the direction of delivery of the slubbings is reversed so that the hooks predominantly lead. It is known that slightly higher draft ratios can be used when the slubbings are drafted in the same direction as they are delivered by the card, and evidence exists to suggest that a greater total draft is possible if the slubbings are drafted twice, once in each direction.

[0013] The method of the present invention may be employed to enable woollen slubbings to be drafted on the card, immediately before winding on the spool.

[0014] The invention thus provides a method of processing whereby woollen slubbings can be drafted as part of the total carding process immediately before winding on the spool, and wound as spools of increased density and net weight of material.

[0015] The invention seeks to provide apparatus to effect drafting of the slubbings between the stage of rubbing to consolidate the slubbings and winding those slubbings, and to further wind these slubbings into spools of significantly increased density.

[0016] According to a second aspect of the present invention there is provided an apparatus for winding slubbings tightly in a carding process, the apparatus including one or more finger guides positioned with their longitudinal axis generally in line with an output from a carding machine and immediately before a winding station thereof, the arrangement being such that a slubbing is fed to each finger guide around which it is wound to produce a stress or tension in the slubbing before it is delivered by the finger guide on to the surface of a spool or spool drive roller of the winding station for collection on the spool.

[0017] The finger may have an acute bend at its delivery end adjacent the spool or spool drive roller and have a pigtail at its opposite input end.

[0018] The invention will be described more fully, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of an apparatus according to a preferred embodiment of the present invention showing in plan view a multiplicity of finger guides and their use for developing tension in a multiplicity of running woollen slubbings, immediately prior to winding these slubbings;

Figure 2 is a cross-section showing one finger guide cooperating with a slubbing winding mechanism of a woollen card;

Figure 3 is an enlarged view of a finger guide according to a preferred embodiment of the invention which can be used to develop tension in a running woollen slubbing;

Figure 4 is an enlarged view of an alternative design of finger guide which can be used to develop tension in a running woollen slubbing;

Figure 5 is similar view to Figure 3 of a second preferred embodiment; and

Figure 6 is a plan view of the finger guide of Figure 5.

[0019] Referring now to figure 1, the apparatus according to a preferred embodiment of the invention comprises a plurality of finger guides 1 mounted on a fixed shaft 2 and having an acute bend 3 at a delivery end thereof and a pigtail 4 at the opposite input end. The shaft 2 with its plurality of finger guides is fixed to a chassis of the woollen card condenser (not shown) in place of the usual assembly of slubbing guides, and can be designed to be accommodated by the same fixing brackets provided for the usual guide assembly.

[0020] Woollen slubbings 5 are fed to the finger guides 1 via the pigtails 4 and are wrapped around the finger guides 1, thereby using a "capstan" effect to develop a stress or tension in the slubbings between the pigtail 5 and the delivery point 3 of the finger guides 1. The acute bends 3 of the delivery points serve to locate the slubbings and guide them precisely on to the surface of the spool drive roller 6. The delivery points 3 of the finger guides 1 are preferably in light rubbing contact with or are very closely spaced from the surface of roller 6 so that contact between the slubbings and a solid surved surface is substantially continuous. From rollers 6 the slubbings pass on to be wound on to the spool 7.

[0021] Referring now to figure 2 which is a section through AA' in figure 1. The finger guides 1 are preferably made from material of circular cross-section and are positioned approximately tangential to the surface of roller 6. The acute bends 3 at the delivery ends of finger guides 1 are in light contact with, or are closely spaced from, the surface of roller 6. The butt ends of the finger guides 1 can be rigidly attached to the shaft 2, upon which the finger guides are supported, or they can be attached in a flexible or hinged manner which allows for irregularities in the surface of roller 6 or in the thickness of the slubbings 5. The acute bend 3 is preferably located close to the point of contact between the spool 7 and roller 6.

[0022] Figure 3 is an enlarged view of a finger guide 1 having a slubbing 5 feeding via the pigtail 4, wrapping the finger guide by 2.1/2 turns, and being delivered at the acute bend 3. The tension developed in the slubbing between the pigtail 4 and the acute bend 3 depends upon the tension up-stream of the pigtail 4 and the number of wraps the slubbing makes around finger guide 1.

[0023] Figure 4 is an enlarged view of an alternative design of finger guide 1 which may be preferred when processing some materials and slubbing counts. In this embodiment of the invention the finger guide 1 is twisted in a spiral shape, the amplitude of which spiral is less than the diameter of the material comprising finger 1. The slubbing 5 is wrapped around the finger 1 in the same sense as the spiral twist of finger 1, and this spiral then generates a false twist in the slubbing, upstream of the finger guides 1, in a known fashion. This false twist can be of advantage in consolidating the slubbing and importing a temporary tensile strength to the slubbing.

[0024] A preferred design of finger guide is illustrated in Figures 5 & 6 which offers some practical advantages when used in an industrial or mill environment. In this embodiment the acute bend 3 is replaced by a flat or spatulate member 9. The shank of the guide is attached to a sleeve 8 which inturn is a sliding fit on the bar 2. The member 9, which can be made of metal or a plastics material, is chamferred at its distal end to enable it to fit closely into the nip between the roller 6 and spool 7.

[0025] In operation, the member 9 rests tangentially on the spool drive roller 6 and the slubbing 5 passes from the guide 1 under the member 9 between it and the spool drive 6. Owing to the slide fit of the sleeve 8 on the bar 2, the finger 1 can rotate and the member 9 therefore rests on the roller 6 under its own weight. The guide is thus self-adjusting to the surface of the roller, ensuring relatively constant pressure on the roller surface independant of the thickness of the slubbing 5 which tends to vary by a small but significant amount in a random manner.

[0026] The spatulate member 9 has the further advantage that its cross-sectional shape inhibits the accumalation of loose fibre which can be produced when running strands of staple fibre are guided or contacted with elements or components of circular cross-section.

[0027] In practice, in order to wind woollen slubbings under high tension on a card it is necessary to increase the winding speed relative to the delivery speed from the card doffer, web divider and slubbing rubbing mechanism. In conventional practice there is a tension draft of about 6% between the delivery speed of the web dividing mechanism and the winding speed of the spool. This tension can be increased by a gear change in the gear drive train to the driving roll 6. Tension drafts of up to 30% have been used experimentally although higher tension drafts are possible, in theory up to about 50%.

[0028] When winding woollen slubbings at high tension, for example 27% tension draft, all of this tension in excess of about 6% is developed across the finger guide 1 between the pigtail 4 and the acute bend 3 or member 9. In practice the tension developed across the finger guide 1 is adjusted by increasing the number of wraps the slubbing makes around the finger guide until the tension in the slubbing upstream of the finger guide is adequately low, as determined by experience. In one example, when winding with a tension draft of 27%, 2.1/2 wraps of the finger were found to be adequate, the net weight of material wound on the spool was increased by 68%, the density of the material on the spool was increased to 0.249 gm/cc and th slubbings were drafted by 18.8%. In other examples increases in winding density of 100% or more have been obtained.

[0029] It will be apreciated that in effecting drafting the contact maintained between the slubbing and the finger guides provides not only the necessary tension in the running slubbing, but also provides a degree of control over the fibres which is necessary for uniform drafting. It will be further appreciated that this mechanism can also be used to effect fibre control in drafting on a conventional spinning machine and in place of common fibre-twisting mechanisms.

Claims

1. A method of handling slubbings in the woollen process, the method including positioning one or more finger guides in the path of the same number of slubbings, and wrapping a slubbing around each finger guide to thereby create a stress or tension therein before the slubbings are directed for further processing.

2. A method of winding slubbings tightly in a carding process, the method including placing one or more finger guides with its longitudinal axis generally in line with output from a carding machine and immediately before a winding spool of the carding machine, feeding a slubbing to each finger guide from the carding machine, wrapping each slubbing around its finger guide to develop a stress or tension therein and delivering from the finger guide the slubbing on to the surface of a spool or spool drive roller for winding on to the spool.

3. A method as claimed in either of claims 1 or 2 in which the output end of the finger guide is postioned as closely as possible to the roller or other means of further processing.

4. A method as claimed in any of claims 1 to 3 in which the amount of tensio or stress is adjusted by altering the number of turns that the slubbings make about the finger guides.

5. An apparatus for winding slubbings tightly in a carding process, the apparatus including one or more finger guides positioned with their longitudinal axis generally in line with an output from a carding machine and immediately before a winding or other further processing station thereof, the arrangement being such that a slubbing is fed to each finger guide around which it is wound to produce a stress or tension in the slubbing before it is delivered by the finger guide on to the further processing station.

6. An apparatus as claimind in claim 5 in which the further processing station is a winding spool and the output end of the finger guide is arranged close to the winding spool or drive roller.

7. An apparatus as claimed in either of claims 5 or 6 in which the finger guide comprises a shank around which the slubbing is wound and a spatulate member under which the output slubbing passes.

8. An apparatus as claimed in any of claims 5 to 7 in which the guide is pivotally mounted on a bar attached to the woolen card.

9 An apparatus as claimed in any of claims 5 to 8 in which the finger guide has a pigtail at its input end.

Drawing