US2872707A - The production of slivers of staple fibres from tows of continuous filaments - Google Patents

Description

PRODUCTION OF SLIVERS OF STAPLE FIBRES FROM TOWS OF CONTINUOUS FILAMENTS Filed Sept. 29. 1954 Feb. 10, 1959 J. CLARKSON 2,872,707

Inventor Ja cit Clar-Jfson A ttomeys United States Patent C) F Jack Clarkson, Sydney, Australia, assignor to British Nylon Spinners Limited, Pontypool, Monmouthshire, England Application September 29, 1954, Serial No. 459,158

9 Claims. (Cl. 19-51) The present invention is concerned with improvements in or relating to the production of slivers of staple fibres from tows of continuous filaments.

There have been many suggestions for the conversion of continuous filaments, such as those of nylon and rayon, into staple fibre type yarns, in which the yarns are made up of numerous short lengths of fibre twisted together into a coherent form. Such yarns, owing to their relatively bulky n'ature, are more suitable for use in certain fabrics e. g. where fullness is required, than yarns of similar denier of continuous filaments. The many suggestions resulted in processes which have involved various ways in which the starting material-usually a tow of continuous filamentsis disrupted to a greater or less extent so as to produce staple fibre, which may be worked up into a yarn either continuously with the disrupting process, or in further separate processes. For instance, in certain of the processes, the continuity of the tow may, or may not, be disrupted completely in measured lengths, and the breaking or cutting of the individual filaments in this disrupting operation may occur in staggered fashion along the length of the tow, followed by doubling, drafting and twisting operations carried out successively on the disrupted material, in one continuous process for the production of a staple'fibre type yarn. In others of the processes, the tow is cutup into separate tufts of staple fibre of which a conglomeration may subsequently be processed into yarn along the lines of the conventional spinning systems, such as the woolen, worsted and cotton systems.

Of the former and continuous processes, it may be said that the end-product is not altogether satisfactoryowing 2,872,707 Patented Feb. 10, 1959 preparatory work, such as opening and carding of the fibres, is necessary only on account of the ravelled and compacted nature of the raw material traditionally used. his on account of an appreciation of this fact, together with the fact that staple fibre produced by cutting-up a continuous filamentary tow is not in a ravelled condition, but consists of fibres of similar length arranged loosely in parallel formation, that some of the first-mentioned processes have been developed. However, as stated previously, none of these processes has been free from defects in the end-product, which defects have been reflected in the quality of the yarn finally produced. Thus, although some of the unwanted traditional operations have been eradicated, this has been at the expense of the quality of the yarns. I It is an object of the present invention to produce slivers of staple fibres from tows of continuous filaments in a process considerably quicker and more simple than any of the traditional processes while maintaining the quality of sliver at least equal to that produced by said traditional methods.

I have found that it is beneficial, from the point of view of the quality of end-product, to make use of .an apparatus similar in function to a combing apparatus comprising a pinned revolving circle to bring about the formation of the coherent continuous product from the tufts of fibres cut from a continuous filamentary tow. Thus, a sideways overlap, rather than a lengthwise overlap of cut tufts is first entailed; and then the fibres are drawn off from the side-by-side array in the normal manner for a combing apparatus, that is sequentially and in the direction of their lengths. The important functions of the pinned revolving circle of the comb are, firstly, to convey the tufts of fibre in sideways overlapping formation to a drawing-off means, and, secondly, to maintain the individual fibres of the tufts in substantially separated condition so that they may be gripped individually by the drawing-off means, thus bringing about their completely random lengthwise positioning in the final sliver. In conjunction with such a combing apparatus there is used a centrifugal cutting apparatus having a rotary member comprising a disc having a radial to one or more of certain causes. For example the staple length of the fibres may vary considerably throughout the product, when the disruption is caused by a breaking operation, thus causing a yarn of non-uniform thickness and/or strength. Again, clumps of coterminous fibres may occur in the material after disruption when this is carried out by a cutting operation owing to the subsequent arrangement of cut tufts of fibres in lengthwise formation and which clumps are deleterious to the cohesion of fibres in, and the irregular appearance of, the end-product. It is of the essence of a properly composed sliver (and subsequent yarn) that the individual fibers therein should be completely randomly spaced in the lengthwise direction. Any process which relies upon the conjunction of tufts of fibre by arranging the tufts in lengthwise formation is denying this essential random property to the sliver; and as it is by no means an easy matter to out each individual filament successively, clumps will always be present to a greater or less degree in slivers produced according -to these cutting processes. Of the processes where continuous filaments are specially cut into staple fibre, it may be said that they are capable of producing the finest and best-quality yarns, but at great expense of time, effort, and waste. An examination of the underlying reasons for the various operations carried out in these last-mentioned processes shows that much of the channel therein connected at one end to an axial entry port and emerging at its other end through the periphery of said disc from which leading end-portions of a tow are forced on to theblade of a stationary cutting means. The comb can accommodate the fibre cut by such apparatus by virtue of the forcing or the lashing of the fibres into the pinned circle immediately after they are cut from the continuous filamentary tow. Normally a comb requires some separate reciprocating means to feed tufts of fibre into the pinned circle and the speed of opperation of the comb is limited to the speed of operation of this means.

One particular embodiment of the invention will now be described with reference to the accompanying drawings, in order that its nature may become more clear. In the said drawings:

Figure l is a diagrammatic plan view of the said embodiment; and

Figure 2 is a diagrammatic elevational view of the embodiment.

In the said embodiment a centrifugal cutter 1 has a disc 3 rotating about a horizontal axis positioned so that of sideways overlap brought about by synchronism of the speeds of rotation of the disc 3 and the annular member 9, and are cut by the stationary blade 5 just before they are lashed into place between the pins 11 on said member. The end-portions 13 of the filaments comprising the tow 15 may be separated from one another prior to cutting by a means such as an air-blast, or by electrostatic repulsion. The comb 7 comprises, in addition to the large pinned rotating annular member 9, one or more rapidly rotating vertical spindles 19 situated both inside and outside the member and positioned so as to remove any long fibres from those deposited on the member, i. e. those extending from the array by more than a predetermined amount, one or more porcupine rollers 21 situated outside the member so as to engage the overlapping fringe 23 of fibres deposited in the pins, and fluted drawing-elf rollers 25 so situated outside the annular member 9 as to be able to draw off the fibres from the member and form them into a coherent and uniform sliver 27, which is deposited into a can 29. Thus it will be appreciated that this embodiment provides a convenient arrangement whereby cut tufts of staple fibre are collected whilst they are in substantially mutually parallel formation and conveniently arranged so that long fibres may be removed and the remainder drawn off into a sliver. In this sliver the fibres will, of course, be so distributed that they are mutually staggered in the lengthwise direction of the sliver since the individual fibres are drawn off successively from the pins of the annular member in the general direction of their own length.

It will be appreciated that instead of using the combing apparatus just described a combing apparatus more nearly approximating to a so-called Noble comb can be used according to the invention, i. e. one comprising an outer and an inner pinned circle, with the fibres being drawn ofl? within the outer circle either from both circles, or, with suitable arrangement of the pins, from the outer circle only, the inner circle being used merely to remove snarled and long fibres in this latter case. However, since in the case of a combing apparatus comprising two circles the external fringe of the fibres in the outer circle may resist to strongly the drawing-off of the fibres interiorly of the circle to form a sliver, it is preferred to use the one annular member described in the embodiment-and perform the combing action by means of an exteriorlysituatedmeans such as the porcupine roller described. Another cogent reason for preparing this embodiment is that no adjustments need be made to the apparatus in order to accommodate cut staple of lengths differing over a sensible range.

What I claim is:

1. A process for the production of a sliver of staple fibres from a single tow of continuous filaments comprising the steps of: centrifugally rotating end portions of saidtow so as to cause continuous forward feeding thereof; cutting said end portions and substantially'immediately thereafter impaling said cut end portions in laterally overlapping and longitudinally coterminous formation in-a tow-receiving zone which is rotatable in a plane substantially normal to the continuous feeding of said end portions; regulating the rotation of said tow receiving zone and the centrifugal feeding and cutting of said end portions so that successive end portions of said tow laterally overlap; and thereafter withdrawing fibres comprising said cut end portions from said receiving zone by gripping the ends of said fibres successively and forming a sliver thereof.

2. The process of claim 1 wherein said fibres are combed prior to being withdrawn from said zone and are thereafter externally withdrawn from said zone.

3. Apparatus for the production of a sliver of staple fibres from a single tow of continuous filaments comprising a rotatable disc having a radial channel therein and an axial entry port for said tow, one end of said channel connecting with said entry port and the other end thereof opening through the periphery of said disc, whereby tow entering said entry port is continuously fed forwardly through said peripheral opening; cutting means adjacent the periphery of said disc for cutting end portions of tow fed forwardly therefrom; an annular towreceiving member rotatable about an axis which is substantially at right angles to that of said disc, said receiving member being positioned so that its periphery is also adjacent said cutting means but on the opposite side thereof from the periphery of said disc; rows of pins on said receiving member for impaling cut end portions of said tow; and means operatively associated with said pins for combing and drawing off successively fibres engaged in the pins of said receiving member.

4. The apparatus of claim 3 including at least one porcupine roller positioned externally of, and operatively associated with, said receiving member for combing said fibres,

5. The apparatus of claim 3 wherein said means for drawing oif said fibres is positioned externally of said receiving; member. 6. The apparatus of claim 4 including at least one rapidly rotating spindle positioned externally of said receiving member between said porcupine roller and cutting means, said spindle being adapted to engage fibres extending outwardly more than a predetermined amount from said receiving member.

7;. A process for the production of a sliver of staple fibres from a single tow of continuous filaments comprising the steps of: centrifugally rotating end portions of said tow so as to cause continuous forward feeding thereof; cutting. said end portions and substantially im- 1 mediately thereafter impaling substantially all of said cutend'portions in laterally overlapping and longitudinally co-terminous formation in a tow-receiving zone which is rotatable in a plane substantially normal to the plane formed by the continuous rotation and feeding of said end portions; regulating the rotation of said tow-receiving zone'and the centrifugal feeding and cutting of said end portions so that successive end portions of said tow laterally overlay; and thereafter withdrawing fibres comprising said cut end portions from said receiving zone by gripping the ends of said fibres successively and forming a sliver thereof.

8. A process for the production of a sliver of staple fibres from a single tow of continuous filaments comprising the steps of: centrifugally rotating end portions of said tow tocontinuously project the end portions forwardly; separating the individual filaments of the projected part of said end portions; cutting said end. portions and substantially immediately thereafter impaling substantially all of said cut end portions in laterally overlapping and longitudinally co-terminous formation in a tow-receiving zone which is rotatable in a plane substantially normal to the plane formed by the continuous rotation and feeding ofsaid end portions; regulating the rotation of said tow-receiving zone and the centrifugal feeding and cutting of said'end portions so that successive end portions of said tow laterally overlap; and thereafter withdrawing fibres comprising said cut end portions from said receiving zone by gripping the ends of said fibres successively and forming a sliver thereof.

9. Apparatus for the production of a sliver of staple fibres from a single tow of continuous filaments comprising a rotatable disc having a radial channel therein and an axial entry portfor' said tow, one end of said channel connecting with said entry port and the other end thereof opening through theperipheiy of said disc, whereby tow ;entering-said entry port-is continuously fed forwardly through said peripheral opening; cutting means adjacent the periphery of said disc for cutting end portions of towfed forwardly therefrom; an annular towreceiving mernber rotatable about an axis which is substantially at right angles to that of said disc, said re- References Cited in the file of this patent UNITED STATES PATENTS Bird Aug. 26, 1941 Runton July 20, 1943 FOREIGN PATENTS Netherlands June 15, 1943 Great Britain Feb. 17, 1954 France Mar. 16, 1942

Images