FR2464322A1 - Warp-knitted fabric incorporating card-doffer web - as bunches of fibre laid-in as weft in sinusoidal form - Google Patents

Abstract

A fabric is constructed using a web of fibres coming directly from the foffer of a carding engine by incorporating bunches of the fibres in a single guide-bar warp-knitted structure. The fibres, 40 mm or more in length, are laid-in weft-wise across the wales of, pref. open pillar stitch in 7-gauge, or finer, warp threads. The fibres cover at least four wales per course, and reverse direction between successive courses, each fibre having at least three reversals along its length. The fabric is produced much more rapidly and cheaply than fabrics consisting of spun yarns alone. It may be made finer than simple stitch-bonded non-woven, yet is stronger and more stable.

Description

 The present invention relates to the manufacture of textile fabrics. We know in the prior art chain knits which are entirely made of yarns. Punch-weave fiber web fabrics are made somewhat similar to warp knitting, where one or two bar warp knitting structures are produced in a fiber web. The simplest structure of this type is not a warp knitting structure at all, that is to say a straight chain or a column stitching, because if this is made without another structure, it there is no connection on the weft side between the columns and no fabric is obtained. However, in the stitching, the stitches are sewn through the web, which has fibers aligned in the direction of the weft, and the fibers of the web constitute the weft side connection so that a fabric is obtained.

 The advantage of such a fabric is that it consists almost entirely of fibers, which are less expensive than yarns or filament yarns. The stitching process is also much faster than weaving.

 However, stitch-binding fabrics have numerous drawbacks which militate against the extension of their use and which virtually exclude their use in clothing, except as a material. lining. Among these drawbacks, mention may be made of poor stability of the weft and poor resistance to pilling, even when long fibers are used in the web, and even after treatment on the oar.

 The present invention relates to a new fabric, as well as a method and a device for its manufacture. This fabric, like a stitch-binding fabric, is composed essentially of a large amount of fiber and a small amount of yarn (although, of course, one can add to the basic structure, for special purposes or for obtain particular effects, as many yarns as desired). Again, like a stitch-binding fabric, the yarn is used in a simple warp knitting structure, even in a single bar straight warp, or a column stitching, and the weft side binding is effected by the fibers. However, the fibers are linked in the fabric in a new way, for example, to give better properties to the textile.

 The present invention relates to a textile fabric which comprises a warp knitted structure and a woven fiber filling in which bundles of fibers pass back and forth adjacent columns and consecutive rows of the structure, so that the fibers of these bundles reverse their weft side orientation between consecutive rows at least three times.

 The warp knitted structure may include a column stitching structure and may be a single guide bar structure. In this case, the weft resistance of the fabric is imparted entirely by the fiber filling.

A very useful range of textile fabrics according to the present invention includes a set of stitching columns of 14 gauge or finer gauge warp yarns, and a fiber filling of about 40 mm long or more, fibers which are wefted. in the columnar stitching structure so as to extend along a sinuous path over at least two columns and at least four rows with at least three inversions in the weft side orientation of most fibers.

In such fabrics, the fibers constitute a system having the essential properties of a weft in a woven fabric.

Orientation reversals on the weft side make it possible to obtain significant resistance to slippage under the effect of forces acting on the weft side because of the significant multiplication of tension coming from the winding angles of high value (Edmonton rule).

In addition, the same characteristics result in good pilling resistance and high stability of the weft compared to a stitch-binding fabric.

 A warp-knit structure with column seams provides good strength and stability properties on the warp side because the warp structure is relatively inextensible. The ream treatment of this fabric, while maintaining the length, or avoiding a significant contraction on the warp side, has the effect of tightening the bites and blocking the structure a little more.

The fabric thus has several advantages over the stitch-binding fabric, with which it may look the most in composition and structure. In addition, the cost of raw materials, and even the costs of production are not significantly higher than those of stitch-binding fabrics, and in fact, the cost of raw materials may even be lower because the stitch-binding fabric must contain, so as to have. sufficient strength on the weft side, more fibers than is strictly necessary to obtain the covering power.

The present invention also provides a method of manufacturing a textile fabric, in which a fiber filling is woven into a knitting structure by back and forth movement, behind a set of warp knitting needles , of a bundle of fibers taken from a veil of fibers introduced at the front of the needles, the direction of this back-and-forth movement reversing between consecutive bites.

 Naturally, it is not necessary for the direction of the reciprocating movement to be reversed between each pair of punctures.

For example, this direction can alternately be reversed and remain the same after successive injections.

 The fibers can be taken at the front of the set of needles by a set of spikes or axes with corresponding spacing, be transported at the back of the needles and moved back and forth along the row needles while the needles are placed in the felling position so that the fibers pass through the location of the needles without engaging, at this stage, in the needles, and the needles then extend between the front points that these are not removed, so that the fibers are positioned against the back of the needles.

 The tips are preferably formed so as to smooth, when they are withdrawn between the needles, the fibers which are placed in front of the needles, and they also preferably comprise parts of entrainer of fibers in the form of hook of so as to precisely position the fiber bundles behind the needles and to limit the movement of these bundles under the effect of the extension of the needles.

 The present invention also provides a device for manufacturing a textile fabric comprising a set of warp knitting needles and a set of spikes with the corresponding spacing, shaped and arranged so as to take bundles of fibers in a veil presented to at the front of the needles, a means for moving the points from a position situated at the front of the needles to a position situated at the rear of the latter while animating the 'points of a downward movement back and forth while the needles are withdrawn to be placed in the slaughter position, and to withdraw the points again and bring them to the front of the set of needles after the needles have been extended between the points, and warp yarn guide means for placing warp yarns in the hooks of the needles while the needles are extended and the tips are removed.

The device preferably comprises a means for preventing the movement of the fibers situated in front of the needles, this means preferably comprising a strip of fabric with low pile pile, such as a velvet, through the pile of which the points can pass so as to mine the fibers located on the upper part of the strip, the bristles limiting the movement on the weft side of the tails of the fibers sampled by the tips at one end.

 The device can also be constructed and operate in the conventional manner of warp knitting or stitching, with the exception, however, of the manner in which the fibers of the ply are introduced into the row of needles. In a conventional stitch liaae, the fibers are provided like a cardboard veil pleated transversely, and are aligned in the weft direction when they reach the needles. Naturally, they are not all arranged precisely in this direction, some being placed according to a certain degree of chance as a result of the imprecise nature of the carding. For the most part, each fiber is sewn into the fabric in an alignment in the weft direction where it is placed by the transverse pleator.

However, according to the present invention, the fibers are introduced lengthwise towards the row of needles, the feeding preferably taking place directly from a carding machine without an intermediate step of transverse pleating.

 The fibers oriented lengthwise are collected and redirected by the short weft-like weft-like tips which stretch over two or more needles.

The present invention will be better understood on reading the following description made in relation to the accompanying drawings, in which
Figure 1 is a schematic representation of a fabric structure
Figure 2 is a schematic representation of another fabric structure
Figure 3 is a perspective view of the device for manufacturing a textile fabric according to the present invention
Figure 4 is a side view of the device shown in Figure 3; and
FIGS. 5, 6 and 7 are side views similar to FIG. 4, which represent the device during the various stages of a puncture cycle.

FIGS. 1 and 2 represent textile fabrics comprising a knitting structure with a rectilinear chain or stitching column 11 in warp threads and a woven fiber filling in which bundles of fibers 12 go back and forth through the adjacent columns 11 and consecutive rows 13 of the structure, so that the fibers of these bundles 12 reverse their orientation on the weft side (that is to say from left to right of the drawings) between consecutive rows at least three times.

The expression halftone has the usual meaning used in the art of warp knitwear. Each puncture 14 of the warp yarn structure shown in FIG. 1 comprises four bundles of discrete fibers woven in it.

 Although beams are said to be discrete, it should be understood that this does not preclude the migration of fibers from one bundle into an adjacent bundle. Such migration is the consequence of the arrangement of the fibers in each card web. A typical arrangement of a unitary filament is represented by the large dotted lines 15 in FIG. 1. The fibers of the fabrics can be 100 mm long and be distributed over three or four gauge needles 14 and have 12 or 15 inversions.

FIG. 2 represents a structure where the weft-side orientation reversals of the fiber bundles only occur every two rows. Each bite has three discrete fiber bundles woven into it.

 Although FIGS. 1 and 2 show only single bar warp knitting structures with open column seams, other warp knitting structures such as jersey fabrics or so-called Atlas fabrics can be used in one or two bar arrangements. In addition, additional wires screened to give an effect, or to increase the weft resistance where desired, can be included.

As in the case of a stitch-binding fabric, special effects can also be obtained by often omitting a stitch thread.

 FIG. 3 represents a device for manufacturing textile fabric comprising a set of warp knitting needles 31 of which only three needles are shown; these needles are very distant from each other and are not to scale to make the drawing clearer. The needles 31 are pointed compound needles, the hooks of the tips 32 being closed by threads 33 sliding in grooves 34. Such needles are used in a stitch binding machine. However, although such needles are suitable, it is not necessary to use pointed needles, since they do not have to penetrate a sheet of fibers as in the case of stitching.

 The needles 31 and the closing wires 33 are driven, in the usual manner, by a reciprocating movement on bars (not shown) with needles and closing wires separated by eccentrics or other arrangements with reciprocating movement so that the needles 31 extend with the hooks 32 open between corresponding felling plates 35 from one another which are carried by a needle bed 36.

Thread guides 37 are carried by a thread guide bar (not shown) which is driven by a movement enabling the warp threads (not shown in FIG. 3) to be laid in the open needle hooks 32 of the desired way.

Such a movement, which produces an open column bite1 is represented by arrow 38.

 The fibers in the form of a carded veil are supplied along the needle bed 36, on which, along the front part of the row of needles, there is a strip of velvet or flock 39.

 The fibers are taken from the velvet by points 41 whose edges 41a resemble hooks and which move through the velvet or the pile hairs and collect the fibers in the form of bundles. The tips 41 have a compound movement, with a component in the direction of the row of needles and a component perpendicular thereto, so that, moving from the front of the needles to the rear of those -this, they also cross two or more needles. When the points return to the front of the needles, the latter are extended, and the points must therefore not include any component of movement in the direction of the row of needles until they are released from the extended needles. A typical movement produced during two puncture cycles is represented by path 42.

 The operation of this device is shown in Figures 4, 5, 6 and 7 which indicate in schematic form the sequence of operations.

 In FIG. 4, the device is shown after the start of manufacture, the fabric 51 already obtained being found behind the needles 31. The needles 31 are extended between the felling plates 35 and the hooks 32 are open, the closing threads 33 being enclosed in the grooves 34. The thread guides 37 are at the front of the open hooks 32, the threads 52 running from the bites 53 formed last at the rear of the needles 31, on the stems of which find the stitches 54 formed during the last stitching cycle.

 The points 41 are in their most advanced position, and are about to move towards the needles 31, the points 41b of the edges 41a / resembling hooks, reaching the pile or the pile of fluff 39. The fibers 40 are laid more or less perpendicular to the row of needles, on the surface of the bristles, and certain fibers are the tails of fibers whose front ends are already-linked to the fabric 51 or are found in the bundles 55 located at the rear extended needles 31 and held against the back thereof by the warp threads 52.

 FIG. 5 represents the chain guides moved to the rear of the needles 31 after a lateral movement of the needle bed so as to place the threads 52 in the hooks 32. The closing threads 33 have closed the hooks 32. The tips 41 have started to move towards and along the row of needles 31, needles which are brought back between the felling stages 35, the old stitches 54 making their way up the stems of the needles 31 More fibers 40 are provided on the bristles 39.

 FIG. 6 represents the needles 31 in their fully retracted position between the plates 35. The old stitch 54 has been cut down so as to form a new stitching 56. The points 41 have now collected bundles 57 of fibers 40 and transport these bundles 57 to the rear of the needle location. The points 41, at this junction, stop moving along the row of needles. As the needles 31 begin to extend from the fully retracted position shown in Figure 6, the closure threads 33 follow them with a slight delay which is sufficient to open the hooks 32 so that the threads can exit the hooks 32 to form new loops on the rods of the needles 31 which move towards the position shown in FIG. 7.

The hooks 41 being stationary, the needles 31 with the open hook extend between them. The hook-shaped profile of the edges 41a makes it possible to maintain the fiber bundles 57 within the range of displacement of the needles 31, so that the fibers of the bundles are all substantially woven in the stitches, which avoids giving a shaggy appearance to the fabric.

The lower edges 41c of the points 41 act as upper plates during the extension of the needles, taking out the loops of the open hooks 32 and raising them on the rod of the needles 31.

 The tips 41 then go back from the position between the extended needles 31, followed by the thread guides 37, to the position shown in FIG. 4, ready to start a new puncture cycle. The warp threads enclose the bundles 57 against the back of the needles, so that they are linked to the stings. While the points 41 go back, the curved back 41c of these smooth the fibers 40 placed on the bristles 39.

 Using this process, with an open column pitting structure, an even fabric is obtained which, however, offers the possibility of fraying of warp threads resulting in scales. This can be avoided by using a second stitching device for warp threads on a second guide bar, or by laterally moving the warp threads by one or more needles. Another method of avoiding the formation of scales using a single bar structure is to incorporate fiber loops with the stitching wire loops as described in Great Britain Patent No. 1,268 630.

 The present invention makes it possible to manufacture not only the basic fabrics represented in the ligures 1 and 2, by means of the technique described in connection with FIGS. 4 to 7, but in a dirty way a wide range of fabrics thanks to the contribution of the various characteristics offered by warp knitting or stitching technology.

The present invention is not limited to the exemplary embodiments which have just been described, it is on the contrary susceptible of variants and modifications which will appear to those skilled in the art.

Claims (14)

 1 - Textile fabric characterized in that it comprises a warp knitting structure and a filling of woven fibers in which bundles of fibers pass back and forth through adjacent columns and consecutive rows so that the fibers of these beams reverse their orientation on the weft side between consecutive rows at least three times.  2 - Textile fabric according to claim 1, characterized in that the warp knitting structure comprises a column stitching structure. 3 - Textile fabric according to one of claims 1 or 2, characterized in that the warp knitted structure is a structure with a single guide bar.  4 - Textile fabric according to claim 3, characterized in that the weft side resistance of the fabric is imparted by the fiber filling.  5 - Textile fabric, characterized in that it comprises a set of stitching columns of warp threads of gauge 7 or finer, and a fiber filling of approximately 40 mm in length or more, fibers which are screened in the columnar stitching structure so as to extend along a sinuous path over at least four rows with at least three inversions of the weft side orientation of most fibers.  6 - A method of manufacturing a textile fabric, characterized in that a fiber filling is woven into a warp knitting structure by displacement in a back-and-forth movement behind a set of knitting needles chain of bundles of fibers taken from a veil of fibers provided at the front of the needles, the direction of back-and-forth movement reversing between consecutive bites. 7 - Method according to claim 6, characterized in that the fibers are removed at the front of the set of needles by a set of spikes at the corresponding spacing animated by a back-and-forth movement and moved up to the rear of the needles while these are extracted to be put in the slaughter position so that the fibers pass through the location of the needles without coming into contact with them, and the needles extend between the tips before removing the tips. 8 - Method according to claim 7, characterized in that during the withdrawal of the tips of the part located between the extended needles, the tips smooth the fibers provided in front of the set of needles.  9 - Method according to one of claims 7 or 8, characterized in that the tips have edges resembling hooks to receive the fibers and thus limit their movement towards the ends of the extended needles. 10 - Method according to one of claims 7, 8 or 9, characterized in that the tips act as upper plates during the extension of the needles, so as to remove the loops from the hooks and to move them on the rods of the needles .  11 - Device for manufacturing a textile fabric, characterized in that it comprises a set of warp knitting needles and a set of spikes with the corresponding spacing, having a shape and being arranged so as to take up bundles of fibers in a veil provided at the front of the needles, a means for moving the tips from a position at the front of the needles to a position at the rear of the needles while animating a movement of back and forth the tips while the needles are put in the slaughter position, and to remove the tips again and bring them to the front of the set of needles after they have been spread between the tips, and a using warp thread guides to place chalne threads in the needle hooks while the needles are extended and the tips are removed.  12 - Device according to claim 11, characterized in that the tips have hook-shaped front edges so as to limit the movement of the fiber bundles held by them towards the ends of the extended needles.  13 - Device according to one of claims 11 or 12, characterized in that the tips have regularly curved edges which are provided to smooth the fibers presented at the front of the row of needles while the tips are removed from the row of needles in preparation for a new stitching cycle.  14 - Device according to one of claims 11 to 13, characterized in that there is a strip of pile fabric or fluff at the front of the row of needles, in which the ends of the points move so to search the fiber located on top of the hairs.