GB1578403A

GB1578403A - Fabric process and method

Info

Publication number: GB1578403A
Application number: GB697078A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-02-22
Filing date: 1978-02-22
Publication date: 1980-11-05

Description

(54) FABRIC PROCESS AND METHOD (71) I, ARNO EDGAR WILDEMAN, of 24, Cloverdale Ocean Apartments, Devonshire, Bermuda, a British subject, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement This invention relates to the production of textile fabric.

Warp knit fabrics are known which are composed entirely of yarn. Stitch bonded fibre fleece fabrics are made in a manner somewhat similar to warp knitting in which single or two bar warp knitting structures are produced in a fibre fleece. The simplest such structure is not really a warp knitting structure at all, namely the straight chain, or pillar stitch, because if this is produced without any other structure, there is no weft-wise connection between the wales, and no faaric is produced. However, in stitch bonding, the stitches are sewn through the fleece, which has fibres aligned in the weft direction, and the fleece fibres constitute the weft-wise connection so that a fabric is produced.

The advantage of such a fabric is that it is composed almost entirely of fibres, which are much less expensive than spun or filament yarn. The stitch bonding process is also much more rapid than weaving.

Stitch bonded fabric has numerous disadvantages, however, which militate against its more widespread use and which virtually exclude its use in apparel, except as an interlining material. Among these disadvantages may be mentioned a low weft stability and low resistance to pilling even when using long fibres in the fleece and even after stentering.

The present invention provides a new fabric as well as methods and apparatus for its production. The fabric, like stitch bonded fabric, is composed essentially of a major proportion of fibre and a minor proportion of yarn (although as much yarn as may be desired can, of coruse, be added to the basic structure for special purposes or effects).

Again, like stitch bonded fabric, the yarn is used in a simple warp knit structure, even in a single bar straight chain, or pillar stitch, and the weft-wise connection is effected by the fibres. However, the fibres are bound into the fabric so as to give improved textile properties.

The invention comprises a textile fabric comprising a warp knit structure and a laid-in fibre filling in which fibre bundles traverse adjacent wales and consecutive courses of the structure so that fibres in such fibre bundles reverse their weft-wise orientation between consecutive courses at least three times.

The warp knit structure may comprise a pillar stitch structure, and may be a single guide bar structure. In the case where a single bar structure consists of a pillar structure, the weft-wise strength of the fabric is imparted entirely by the fibre filling.

A very useful range of textile fabrics according to the invention comprise a set of pillar stitch wales of warp yarn in 14 gauge or finer, and a filling of fibres of about 40 mm length or longer, which fibres are laid-in to the pillar stitch structure so as to extend in a sinuous path over at least two wales and at least four courses with at least three reversals in the weft-wise orientation of most'fibres.

In such fabrics, the fibres form a system having the essential properties of a weft in a woven fabric. The reversals of weft-wise orientation give rise to a substantial resistance to slip under weft-wsie forces because of the large tension multiplier arising out of the high wrap angles (Amonton's rule). Moreover, the same features result in good pilling resistance and high weft stability as compared to stitch bonded fabric.

A pillar stitch warp structure gives good warp-wise strength and stability because the chain stitch structure is relatively inextensible.

Stentering this fabric, while holding to length, or holding against substantial warp-wise contraction, has the effect of tightening up the stitches and locking the structure further.

The fabric thus possesses several advantages over stitch bonded fabric, which perhaps it resembles most closely in composition and structure. At the same time, the raw material, and even the production costs, are not substantially more than those of stitch bonded fabric-and indeed the raw material cost may even be lower because stitch bonded fabric, in order to have sufficient weft-wise strength needs to contain more fibre than is strictly necessary for covering power.

The invention also comprises a method for making a textile fabric in which a fibre filling is laid in to a warp knit structure by traversing, behind a set of warp knitting needles, fibre bundles taken from a fibre web supplied to the front of the said needles, the direction of such traversing reversing between consecutive stitches.

It is, of course, not necessary for the traverse direction to reverse between each pair of stitches. For example, the said direction can alternately reverse and stay the same after successive stitches.

The fibres may be picked up from in front of the said set of needles by a set of correspondingly spaced nebs or pins and carried to behind the needles and traversed there along the needle row while the needles are withdrawn into the knockover position so that the fibres pass through the needle position without at that stage engaging the needles, and the needles are then extended between the nebs before the nebs are withdrawn so that the fibres are located against the backs of the needles.

The nebs are preferably so formed as to smooth on their withdrawal from between the needles, the fibres that are lying in front of the needles, and they preferably also have hook-shaped fibre-engaging parts to locate the fibre bundles precisely behind the needles and limit movement of the fibre bundles under the action of the extending needles.

The invention also comprises apparatus for making a textile fabric comprising a set of warp knitting needles and a set of correspondingly spaced nebs, shaped and arranged to operate so as to pick up fibre bundles from a web supplied to the front of the needles, means to move the nebs from a position in front of the needles to a position behind the needles while traversing the nebs as the needles are withdrawn into the knockover position, and to withdraw the nebs again to the front of the needle set after the needles have been extended between the nebs, and warp thread guide means adapted to lay warp threads in the needle hooks while the needles are extended and the nebs withdrawn.

The apparatus preferably has means to restrict motion of the fibres lying in front of the needles, such means preferably compris ing a strip of low-pile fabric such as velvet through the pile of which the nebs can pass in order to undermine the fibres lying on top of the strip, the pile whereof restricts weft-wise motion of the tails of any fibres picked up by the nebs by one end.

The apparatus can otherwise be constructed and operated in conventional warp knitting or stitch bonding fashion, save for the manner of feeding the fleece fibres to the needle row. In conventional stitch bonding the fibres are fed as a cross-folded card web, and are aligned in the weft-wise direction by the time they reach the needles. Of course, they are not arranged all precisely in the weft-wise direction, there being some degree of randomness as a result of the imprecise nature of carding. For the most part each fibre is sewn in to the fabric in the weft-wise alignment in which it is placed by the cross-folder.

According to the present invention, however, the fibres are fed lengthwise towards the needle row, the feed being preferably direct as from a carding machine without any intermediate cross-folding step.

The length-wise orientated fibres are collected and re-orientated by the nebs into short weft-like lays extending over two or several needles.

Embodiments of fabric, of the method for making the same and apparatus therefor will now be described with reference to the accompanying drawings in which: Figure 1 is a diagram of one fabric structure, Figure 2 is a diagram of another fabric stucturer, Figure 3 is a perspective view of apparatus for making a textile fabric according to the invention, Figure 4 is a side view of the apparatus shown in Figure 3, Figures 5, 6 and 7 are side views like Figure 4, showing the apparatus during various parts of a stitching cycle.

Figures 1 and 2 illustrate textile fabrics comprising a warp knit structure of straight chain or pillar stitch wales 11 of warp threads and a laid in fibre filling in which fibre bundles 12 traverse adjacent wales 11 and consecutive courses 13 of the structure so that fibres in such fibre bundles 12 reverse their weft-wise (i.e. left to right, in the drawings) orientation between consecutive courses at least three times. The expression "laid in" has its usual connotation in the warp knitting art. Each stitch 14 of the warp thread structure shown in Figure 1 has four discrete fibre bundles laid into it.

Although the bundles are said to be discrete, it is to be understood that this does not preclude migration of fibres from one bundle into an adjacent bundle. Such migration is a consequence of the arrangement of fibres in the card web. A typical arrangement of a single filament is shown by the heavy dashed 15 in Figure 1. Fibres in practical fabrics may be 100 mm long and spread over three or four 14 gauge needles may exhibit 12 or 15 reversals.

Figure 2 shows a structure in which reversals of weft-wise orientation of the fibre bundles happens only every other course.

Each stitch has three discrete fibre bundles laid into it.

Although Figures 1 and 2 illustrate only open pillar stitch single bar warp knit structures, other warp knit structures such as tricot or Atlas can be used in single or two bar arrangements. Furthermore, additional laid-in yarns, for effect, or increased weft strength where desired, can be included.

As with stitch bonded fabric, special effects can also be brought about by leaving out a stitching thread every so often.

Figure 3 illustrates apparatus for making a textile fabric comprising a set of warp knitting needles 31, of which only three are shown, and these widely spaced and not to scale, for clarity's sake. The needles 31 are shown as pointed compound needles, the pointed hooks 32 being closed by closing wires 33 sliding in grooves 34. Such needles are used in stitch bonding machinery. However, although these needles are convenient, it is not necessary to use pointed needles, as they do not have to penetrate a fibre fleece as in stitch bonding.

The needles 31 and closing wires 33 are reciprocated on separate needle and closing wire bars (not shown) by eccentrics or other reciprocatory arrangements in the usual way so that the needles 31 are extended with the hooks 32 open, between correspondingly spaced knockover sinkers 35 carried on a bed 36.

Thread guides 37 are carried in a thread guide bar (not shown) which is given a motion so as to lay the warp threads (not shown in Figure 3) into the open needle hooks 32 in any desired manner. One such motion, that producing an open pillar stitch is indicated by the arrow 38.

Fibres in the form of a corded web are delivered along the bed 36, on which, along the front of the needle row, is a strip of velvet or flock 39.

The fibres are taken from the velvet by nebs 41 which have hook-like edges 41 a that move through the velvet or flock pile and gather up the fibres into bundles. The nebs 41 have a compound motion with components along the needle row and at right angles to the needle row so that in moving from in front of the needles to behind the needles, they also traverse over two or more needles. When the nebs return to the front of the needles the needles are extended, and the nebs must therefore have no component of movement along the needle row until they are clear of the extended needles. A typical motion during two stitching cycles is shdwn by track 42.

The operation of this apparatus is illustrated in the diagrammatic sequence Figures 4, 5, 6 and 7.

In Figure 4, the apparatus is shown after fabrication has begun, with the fabric 51 already produced lying behind the needles 31.

The needles 31 are extended between the knockover sinkers 35, and the hooks 32 are open, the closing wires 33 being withdrawn into the grooves 34. The thread guides 37 are in front of the open hooks 32, the threads 52 running from the last-formed stitches 53 behind the needles 31, on the shanks of which are the loops 54 formed during the last stitching cycle.

The nebs 41 are in their forwardmost position, about to move towards the needles 31, the points 41b of the hook-like edges 44a reaching into the velvet or flock pile 39. Fibres 40 are lying, more or less at right angles to the needle row, on the pile surface, and some of the fibres are the tails of fibres of which the leading ends are already bound into the fabric 51 or in bundles 55 lying behind the extended needles 31 and held against the backs thereof by the warp threads 52.

Figure 5 shows the warp guides moved behind the needles 31 after a lateral shogging motion to lay the threads 52 into the hooks 32. The closing wires 33 have closed off the hooks 32. The nebs 41 have begun to move towards and along the row of needles 31, which are retracting between the knockover sinkers 35, the old loops 54 working their way up the shanks of the needles 31. More fibres 40 are being delivered on to the pile 39.

Figure 6 shows the needles 31 fully retracted between the knockover sinkers 35.

The old loop 54 has knocked over to form a new stitch 56. The nebs 41 have now collected bundles 57 of fibres 40 and carried these bundles 57 rearwardly of the needle position.

The nebs 41 at this juncture stop moving along the needle row. As the needles 31 begin to extend from the fully retracted position shown in this Figure 6, the closing wires 33 follow them with a slight delay sufficient to open the hooks 32 so that the threads can move out of the hooks 32 to form new loops on the shanks of the needles 31 which move to the Figure 7 position.

With the nebs 41 stationary, the openhooked needles 31 extend between them. The hook-like shape of the edges 41 a holds the fibre bundles 57 within the limits of movement of the needles 31, so that the fibres of the bundles are substantially all laid-in to the stitches, avoiding hairiness of the fabric. The lower edges 41c of the nebs 41 act as top sinkers during the extension the needles, taking the loops out of the open hooks 32 and up on to the shanks of the needles 31.

The nebs 41 then retract from between the extended needles 31 followed by the thread guides 37 to the position shown in Figure 4, ready to begin a new stitching cycle. The warp threads trap the bundles 57 against the backs of the needles so that they are bound-in to the stitches. As the nebs 41 retract, the curved backs 41c thereof smooth down the fibres 40 lying on the pile 39.

Using this method of operation, with an open pillar stitch structure, a smooth fabric is obtained, which, however, has the possibility of unravelling of the warp threads so as to result in ladders. This may be avoided by the use of a second warp thread stitching system on a second guide bar, or by laterally displacing the warp threads by one or more needles every so often. Another method of avoiding laddering using a single bar structure is to include fibre loops in with the stitching thread loops in the manner described in U.K. Patent 1 268 630.

This invention is capable of producing not only the basic fabrics shown in Figures 1 and 2 by the basic technique described with reference to Figures 4 to 7, but also a wide range of fabrics with the addition of various features of warp knitting or stitch bonding technology.

WHAT I CLAIM IS: 1. A textile fabric comprising a warp knit structure and a laid-in fibre filling in which fibre bundles traverse adjacent wales and consecutive courses such that fibres in such fibre bundles reverse their weft-wise orientation between consecutive courses at least three times.

2. A textile fabric according to claim 1, in which the warp knit structure comprises a pillar stitch structure.

3. A textile fabric according to claim 1 or claim 2, in which the warp knit structure is a single guide bar structure.

4. A textile fabric according to claim 3, in which weft-wise strength in the fabric is imparted by the fibre filling.

5. A textile fabric comprising a set of pillar stitch wales of warp yarn in 7 gauge or finer, and a filling of fibres of about 40 mm length or longer, which fibres are laid in to the pillar stitch structure so as to extend in a sinuous path over at least four courses with at least three reversals in the weft-wise orientation of most fibres.

6. A textile fabric substantially as hereinbefore described with reference to the accompanying drawings.

7. A method for making a textile fabric in which a fibre filling is laid in to a warp knit structure by traversing behind a set of warp knitting needles fibre bundles taken from a fibre web supplied to the front of the said needles, the direction of such traversing reversing between consecutive stitches.

8. A method according to claim 7, in which the fibres are picked up from in front of the said set of needles by a set of correspondingly spaced nebs and traversed and carried to behind the needles as the needles are withdrawn to the knockover position so that the fibres pass through the rcedle position without engaging the needlcs, and the needles are extended between the nebs before the nebs are withdrawn.

9. A method according to claim 8, in which as the nebs are being withdrawn from between the extended needles, they smooth the fibres being supplied to the front of the needle set.

10. A method according to claim 8 or claim 9, in which the nebs have hook-like edges to receive the fibres and so limit movement thereof towards the points of the extended needles.

11. A method according to claim 8 or claim 9 or claim 10, in which the nebs act as top sinkers during the extension of the needles whereby to take the loops out of the hooks and move them on to the shanks of the needles.

12. A method for making a textile fabric substantially as hereinbefore described with reference to the accompanying drawings.

13. Apparatus for making a textile fabric comprising a set of warp knitting needles and a set of correspondingly spaced nebs, shaped and arranged to operate so as to pick up fibre bundles from a web supplied to the front of the needles, means to move the nebs from a position in front of the needles to a position behind the needles while traversing the nebs as the needles are withdrawn to the knockover position, and to withdraw the nebs again to the front of the needle set after the needles have been extended between the nebs, and warp thread guide means to lay warp threads in the needle hooks while the needles are extended and the nebs withdrawn.

14. Apparatus according to claim 12, in which the nebs are formed with hook-shaped leading edges to limit movement of fibre bundles held therein towards the points of the extended needles.

15. Apparatus according to claim 12 or claim 13, in which the nebs are formed with gently curved edges adapted to smooth down fibres presented to the front of the needle row as the nebs withdraw from the needle row in preparation for another stitching cycle.

16. Apparatus according to any one of claims 12 to 14, in which there is a strip of pile fabric or flock in front of the needle row through which the points of the nebs travel to undermine fibre lying on top of the pile.

17. Apparatus substantially as hereinbefore described with reference to the accompaying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. warp threads trap the bundles 57 against the backs of the needles so that they are bound-in to the stitches. As the nebs 41 retract, the curved backs 41c thereof smooth down the fibres 40 lying on the pile 39. Using this method of operation, with an open pillar stitch structure, a smooth fabric is obtained, which, however, has the possibility of unravelling of the warp threads so as to result in ladders. This may be avoided by the use of a second warp thread stitching system on a second guide bar, or by laterally displacing the warp threads by one or more needles every so often. Another method of avoiding laddering using a single bar structure is to include fibre loops in with the stitching thread loops in the manner described in U.K. Patent 1 268 630. This invention is capable of producing not only the basic fabrics shown in Figures 1 and 2 by the basic technique described with reference to Figures 4 to 7, but also a wide range of fabrics with the addition of various features of warp knitting or stitch bonding technology. WHAT I CLAIM IS:

1. A textile fabric comprising a warp knit structure and a laid-in fibre filling in which fibre bundles traverse adjacent wales and consecutive courses such that fibres in such fibre bundles reverse their weft-wise orientation between consecutive courses at least three times.