FR2668504A1 - Method for producing a cloth which stretches in the warp (chain) direction and novel type of cloth thus produced - Google Patents

Abstract

Improved method making it possible to produce a cloth which stretches in the warp direction, which can be used particularly in the garment field, which method consists in producing the cloth using a layer of parallel warp threads, which consists of an alternation of highly stretchy threads and of spun fibres, the type of weave of the cloth being chosen from among those in which the threads operate in pairs. It is characterised in that: - when the shed is formed, the two threads (0 and alpha ) of each pair operating simultaneously are separated from one another by a comb tooth; - the headling (looming) of the threads is a sequenced headling with two bodies (4, 5), one for the non-stretchy threads, the other for the stretchy threads, and - the comb (1) separating the threads of the warp from one another is a double comb, including two rows of teeth arranged in a configuration in which one row is staggered with respect to the other, and two pairs of threads being threaded through per tooth.

Description

PROCESS FOR PRODUCING AN EXTENSIBLE FABRIC IN THE
CHAIN SENSE AND NEW TYPE OF FABRIC SO REALIZED.

 The present invention relates to an improved process for making fabrics that can be stretched in the warp direction, and more particularly fabrics that can be used in the field of clothing and which consist mainly of natural fibers, such as cotton fibers.

 To impart extensibility properties (in warp and / or in weft) to fabrics, it has been proposed for a long time to use yarns having in themselves high elongation and elastic return properties, such as complex yarns with a core (of the wrapped or assembled type), the core of which is constituted by an elastomeric yarn (or the like), covered with a fibrous structure such as a fiber yarn, an elastic textured yarn.

 Such complex elastic yarns which have been the subject of numerous publications (see in particular FR-A2 192 568) make it possible to obtain fabrics having a great extensibility, but are however not suitable for the production of articles usable in the clothing, given their high cost due to the complexity of manufacturing such yarns, and above all the practically impossibility of dyeing them into yarns and of obtaining articles having a very dense texture while retaining great lightness.

 French patent 2,286,219 proposes a solution which makes it possible to solve these problems to a certain extent.

 In general, according to the teachings of this document, an elastic warp and weft fabric is produced by weaving on a specific weave of a layer of warp threads constituted by an alternation of a bare stretched elastomeric thread and a filling thread also stretched, weaving being carried out so that in each tooth of the comb, at least one stretched bare elastomeric thread and at least one filling thread are introduced in parallel, the two threads working together in the same weave.

 Such a method makes it possible to obtain flat elastic woven articles, which are light, and which give satisfaction in particular in the case where the filling thread consists of a synthetic thread textured by false twist (foam thread, polyamide for example).

 On the other hand, tests made in this direction to produce articles based on cotton threads, and in which the chain was constituted by an alternation of cotton threads and stretchy threads of the type comprising a polyurethane (or equivalent) core associated to a textured swelling yarn with continuous filaments (such as that marketed by the company L.PAYEN & CIE under the brand "PAGASTIC"), have shown that it was not satisfactory, especially in the case where it is desired make fabrics with a dense warp texture, because in such a case, the neighboring threads tend to roll one on the other, which causes in the fabric formed stripe defects in the warp direction, incompatible defects also well for the production of fabrics with effects (such as tiles, plaid, etc.), and which are obtained from previously dyed threads, than for plain fabrics.

 Now we have found, and this is what is the subject of the present invention, an improved method which makes it possible to solve these problems.

In general, the invention therefore relates to an improvement made to the process allowing the production of such a stretch fabric in the warp direction, usable in particular in the clothing field, process which consists in making the fabric using a web of threads of parallel chain constituted by an alternation of highly extensible threads and fiber yarns, the weave of the fabric being chosen from those according to which the threads work in pairs, the method according to the invention being characterized in that
- during the formation of the crowd, the two wires of each pair working simultaneously, are separated from each other by a comb tooth
- the shedding of the threads is a shedding followed by two bodies, one for the non-stretchy threads, the other for the stretchy threads and;
- The comb separating the son of the chain from each other is a double comb, comprising two rows of teeth staggered in a row relative to the other, and the threading being of two pairs of threads per tooth.

 In accordance with the method according to the invention and in a known manner, during weaving, the elastic warp threads will be kept under high tension.

 As said previously, thanks to the method according to the invention, it is possible to use as non-stretchable yarns spun with fine fibers, such as cotton, wool or similar yarns. As weft yarns, any type of textile material can be used, but yarns of the same kind as the non-stretch yarns of the warp will advantageously be used.

Such a method also makes it possible to use previously dyed threads making it possible to obtain Scottish, striped effects.
The invention and the advantages which it brings will however be better understood thanks to the example of embodiment given below by way of indication but not limitation, and which is illustrated by the appended diagrams in which
- Figure 1 is a schematic side view showing the manner in which the weaving operation is carried out in accordance with the invention;
- Figure 2 (subdivided into Figures 2a, 2b, 2c and 2d), is a conventional graphic representation illustrating the way in which the fabric is produced according to the method according to the invention, the threads not being represented by blackened areas as this is the rule in such a representation, but by the signs 11011 and "a", the sign "O" corresponding to a non-extensible yarn, and the sign "a" to a highly extensible yarn.

Conventionally, the sub-figures 2a to 2d represent
. Figure 2a: putting back the warp threads,
. Figure 2b: the comb used on the loom,
. FIG. 2c: the fabric obtained,
. Figure 2d: the command sequence for
smooth for warp threads.

 - Figure 3 is an enlarged view of the special comb and threading allowing the implementation of the method according to the invention.

Example
On a conventional type loom, whose comb weaving width (1) is 179 cm, two beams of thread are mounted
- one (2) comprising 4480 "O" extensible wires (of the type marketed by the company L.PAYEN under the brand "PAGASTIC", under the reference PA FT 1/78/17), having a titer of 95 dtex ( NM105);
- the other (3) also consisting of 4480 threads, but based on a cotton "a" yarn having a count of 360 dtex (NM 1/28).

 The screening is carried out with a cotton thread (NM 1/28 equivalent to 360 dtex), at the rate of 17 picks on the loom.

 The weaving operation is carried out in accordance with the method according to the invention using a two-body shed (4,5), the shed being a followed compound shed as illustrated in FIG. 2a; the non-extensible wires "a" are preferably mounted on the rear body (5) (if one considers the shape of the loom), while the extensible wires "O" are, mounted on the front body (4).

 According to one of the essential characteristics of the process according to the invention, the comb (1) has a structure as illustrated in FIGS. 2b and 3, and has two rows (la, lb) of teeth (see FIG. 3), arranged in staggered rows in relation to each other. Thanks to such an arrangement, it is therefore possible to achieve a very high density of warp yarns.

In accordance with the method according to the invention, the re-entry of the warp threads "O" and "a" inside the comb is carried out so that the threads, at the outlet of the comb, are subdivided in pairs, the a pair arranged on either side of a tooth, being intended to work together in the weave of the fabric.

 By proceeding in this way, a perfectly flat fabric is obtained at the exit from the loom, having no appearance defect and which, after conventional finishing treatment, can be used to make articles of clothing such as pants. The fabric obtained in accordance with the process according to the invention is moreover of a reduced production cost and can be produced as well from previously dyed threads making it possible to produce fabrics with effects (stripes, tiles, plaids, etc.), articles obtained being completely free from defects, in particular from scratches.

 Of course, the invention is not limited to the embodiment described above, but it covers all the variants produced in the same spirit.

Claims (3)

 1 / Improved process allowing the production of a stretch fabric in the warp direction, usable in particular in the clothing sector, process which consists in making the fabric using a sheet of parallel warp threads constituted by an alternation of highly stretchy threads and of spun with fibers, the weave of the fabric being chosen from those according to which the threads work in pairs, characterized in that  - during the formation of the crowd, the two wires (0 and a) of each pair working simultaneously, are separated from each other by a comb tooth  - The shedding of the threads is a shedding followed by two bodies (4,5), one for the non-stretchy threads, the other for the stretchy threads and; ;  - the comb (1) separating the threads of the chain from each other is a double comb, comprising two rows of teeth staggered in a row relative to the other, and the threading being of two pairs of threads per tooth.  2 / Stretch fabric in the warp direction obtained by the implementation of the method according to claim 1, characterized in that it comprises a chain of alternating highly stretchable threads and fiber yarns, said stretchable threads comprising a polyurethane core or equivalent, associated with a textured swelling yarn with continuous filaments and the fiber yarns being cotton yarns.  3 / Fabric according to claim 2, characterized in that it is based on previously dyed son.