EP1159475B1 - Method for obtaining a woven fabric - Google Patents

Abstract

A method for obtaining a woven fabric which comprises continuously unwinding from a single warp beam, a set of parallel warp yarns; passing the set of warp yarns on a whip-roll; forming a shed using heald means; inserting a weft yarn in the shed in the proximity of a face stitch to form a fabric; and finally uniformly pulling and batching the resulting fabric. In one aspect of the invention, the method consists of, in the proximity of the shed opening stitch, heating the warp yarns, and then cooling said warp yarns in the shed before they reach the heald means, characterized in that only part (34) of the warp yarns is heated. In one aspect of the invention, the shed may be defined in the forward movement direction of the warp, for example, by the opening stitch and the face stitch.

Description

Technical area

The invention relates to the field of the textile industry. It concerns more precisely the production of fancy fabrics used for clothing or similar. It is more particularly aimed at improvements made to weaving processes combined with operations for processing warp threads. She also relates to the fabrics thus obtained which have original patterns.

Previous techniques

As we know, some fancy fabrics have patterns that are constituted by warp threads of nature or having different properties, which are juxtaposed: It is therefore necessary when manufacturing such a fabric, that the warp yarns come from two or more different beams. So the sons from the two beams form two parallel layers which are mixed at the level boarding bars, before entering the crowd training area. The two beams are necessary to allow a different advance of the layers of sons who are either of a different nature or who have undergone prior treatment and different such as dyes.

Thus, the problem of managing multiple beams arises in several types of fancy fabrics such as in particular fabrics with an appearance particularly original, similar to cotton crepe fabrics, more generally called "seersucker".

We also encounter the problem of managing a large number of beams in the production of striped fabrics.

Indeed, in both cases, when one wishes to associate within the same several types of yarn which are either different in nature or colored different, this involves tedious pre-weaving operations even impossible when the chain son to associate are very different in nature. In addition, when the different threads are associated within the same beam, their distribution and their distribution are frozen, so it is impossible to modify the number and width of each of the specific property areas.

So, for example, the width of the stripes is determined intangibly by the distribution of the threads of the colors used. In other words, it is necessary to have a specific beam for the realization of each motif, which obviously is extremely costly and is time consuming when wish to change patterns.

The problem is not solved when using two different beams each comprising a type of wire. Indeed, the mechanism allowing to associate in a single layer, at a boarding bar, two wires from two different beams only ensures a specific mix and a given and fixed distribution of the wires from these two beams. In other words, looms used for making such items are absolutely not versatile but on the contrary often dedicated to the realization of a single type of fabric.

One of the objectives of the invention is to allow the production of fabrics fantasy chosen from a wide variety, using a unique loom as simple as possible, and carrying a single beam formed with a single yarn quality.

Statement of the invention

• on déroule en continu, depuis une seule ensouple, une nappe de fils de chaíne parallèles ;
• on fait passer ladite nappe sur un rouleau porte-fils ;
• on forme une foule au moyen de lisses, ladite foule étant définie dans la direction d'avancée de la chaíne, à l'entrée par un point d'ouverture de la foule, et de l'autre côté par un point de façure ;
• on insère un fil de trame dans la foule au voisinage du point de façure pour former une étoffe ;
• et enfin on tracte régulièrement et on enroule l'étoffe ainsi formée ;

et dans laquelle au voisinage du point d'ouverture de la foule, on provoque un échauffement des fils de chaíne, suivi d'un refroidissement desdits fils de chaíne dans la foule avant qu'ils n'atteignent les lisses. The invention therefore relates to a method for obtaining a woven fabric. This method comprises, in a known manner, the following stages in which:

• we unroll continuously, from a single beam, a sheet of parallel chain threads;
• passing said sheet over a thread-carrying roller;
• a crowd is formed by means of beams, said crowd being defined in the direction of advance of the chain, at the entrance by a point of opening of the crowd, and on the other side by a point of shaping;
• we insert a weft thread into the crowd in the vicinity of the stitching point to form a fabric;
• and finally we regularly tow and roll up the fabric thus formed;

and in which in the vicinity of the opening point of the crowd, it causes a heating of the chain son, followed by a cooling of said chain son in the crowd before they reach the healds.

The process according to the present invention is characterized in that one causes the heating of only part of the chain son.

In other words, the process according to the invention treats in a differentiated manner part of the warp threads, which means that on the total width of the fabric, only part of its chain son undergoes the heating stage which gives them specific properties.

Thus, in the case where one causes the heating of the warp threads to a sufficient temperature to cause local elongation and decrease modulus of elasticity, the fabric thus obtained has warp threads from a single beam, delivering homogeneous threads, but which are transformed in a way differentiated during the weaving operation. In this way, when the fabric obtained undergoes a subsequent removal step, the chain wires behave in a way different depending on whether or not they underwent the heating treatment during the weaving. It follows that the different length of the warp threads and the phenomenon of additional shrinkage, causing different deformations in the tissue and distributed according to the selection of the son of chain having undergone or not heating during weaving. Indeed, the son of chain having undergone the treatment thermal during weaving, have a lower shrinkage capacity than those have not been heated, and cause the appearance of thick embossed zones when the unheated wires shrink. The effects thus obtained are strongly pronounced, and variable depending on the threads used.

In practice, according to the process according to the invention, downstream of the yarn-carrying roller, the web in two series of yarns, and a spacing is maintained between the two series of chain son, to submit only one of the two series to the characteristic heating. In this way, by means of two simple spanning rods, we split the tablecloth according to the desired geometry, selecting the number and position of the wires to be heated under tension. Thanks to the simplicity of the separation mechanism, it is possible to vary without any difficulty the distribution between the two series from the aquifer in selecting at will the desired distribution. We can for example choose not to heat a smaller part of the warp threads, keeping a larger one number of unheated wires, which will then undergo a strong shrinkage. On the contrary, choose to heat a majority of the warp threads to obtain still others effects.

The configuration of each series can also be chosen by according to the will of the user, and without any restriction, with the possibility to obtain various effects on the width of the fabric. So it is possible to create each series of warp threads using identical numbers of threads gathered by group or by group. You can also vary the number of wires by beam across the width of the fabric, and with total freedom of choice.

Advantageously in practice, the method according to the invention can further include a "free" heat treatment step. This treatment can advantageously be a scalding or even a hot air treatment, without tension constraint as can be obtained on continuous materials called "Tumbler". Thus, by forcing the withdrawal to free, one accentuates the difference of behavior between the wires having undergone heating and the others, which causes more pronounced volume deformations. In a form advantageous of the process, the step of withdrawing a calendar can be followed, or more generally of a crushing of the patterns formed, to obtain an appearance different and flattering exterior.

The invention also relates to the textile fabrics obtained by the process according to the invention, and which have an appearance close to the tissues called "Seersucker".

Advantageously in practice, the warp threads used can be threads crepe and / or textured crepe yarns, that is to say having undergone a twisting step and a false twist step. We can also vary the effects within the fabric by using different and batted weft threads.

As already said, the fabric obtained can have extremely varied effects depending on whether the yarns that have undergone the heat treatment during weaving are in number equal or more or less numerous than those having retained their capacity without having been heated. In addition, the effects may also be varying choosing within the series of chain wires to heat beams with a distribution either uniform or variable according to a choice of the manufacturer.

• on amène au contact de la partie seulement des fils de chaíne qui subit l'échauffement, un papier transfert portant les motifs de colorants apte à être transféré sur les fils de chaíne sous l'effet dudit échauffement ;
• on fait défiler ce papier transfert en rapport de vitesse avec la vitesse d'avancée de la nappe des fils de chaíne, de manière à ce que le transfert du motif de colorant n'ait lieu que sur la partie seulement des fils de chaíne qui subit l'échauffement.

The process according to the invention can also prove to be advantageous for producing patterns on the warp threads, from a transfer paper. Thus, more precisely, in accordance with this particular implementation of the method:

• it brings into contact with only the part of the chain son which undergoes heating, a transfer paper carrying the dye patterns capable of being transferred to the chain son under the effect of said heating;
• this transfer paper is scrolled in relation to speed with the speed of advance of the web of warp threads, so that the transfer of the dye pattern takes place only on the part only of the warp threads which undergoes heating.

In other words, the invention consists in dissociating the web of warp threads of threads intended to receive the impression in order to form bundles of threads on which are printed the patterns present on the transfer paper, and which form when gathered with the other threads of the tablecloth, the stripes characteristics. In this way, only the threads forming the stripes on the fabric are printed, and the borders of the stripes on the fabric are perfectly materialized single wire level. The stripes are therefore perfectly straight. We indeed knows that in conventional paper transfer printing processes with stripes, the border between two paper stripes is not always localized on a single wire, but on the contrary tends to navigate and to be distributed over several wires, which constitutes a defect of regularity.

In addition, it has been observed that, surprisingly, the wires situated at the end side of scratches receive excess dye when printed and have a higher color intensity than the rest of the strip. This overcurrent reinforces the limit of the stripe by giving a setting effect particularly appreciable.

In practice, when one wishes to obtain stripes of uniform width, one determines each series of warp threads, so that they are made up of bundles of wires, each comprising a number of neighboring wires. Well understood, the invention is not limited to this single embodiment, but allows also to obtain stripes of any size, by selecting regularly or not, and with total freedom, the number of sons who will undergo the printing step. A very large variety can thus be obtained since it is possible to select wire by wire, and to obtain extreme stripes limited to a single wire in width.

We can multiply the effects, in particular by selecting a transfer paper which has a striped pattern parallel to the direction of travel of the paper, and such that one of the borders between said bands is brought in the vicinity of the part of the son of chain on which had the impression. In other words, on the same stripe obtained by selecting part of the warp threads, you can print a pattern additional, itself made up of scratches, possibly moving by the variation of the mixture of two neighboring colors.

As already said, the invention also relates to woven fabrics, according to the invention, and which have a plurality of parallel stripes. We observe as already said, that each stripe thus presents a border which the intensity of the color is greater than that of the rest of the stripe.

Brief description of the figures

La figure 1 est une vue de côté d'un métier à tisser fonctionnant selon le procédé conforme à l'invention, montré dans son application pour la réalisation de tissus du type "seersucker".

La figure 2 est une vue de dessus de la nappe au niveau de la zone caractéristique de l'invention dans laquelle est provoqué l'échauffement préalable au tissage proprement dit.

La figure 3 est une vue de dessus de la même zone, mais avec une répartition différente des deux séries de fils de chaíne.

La figure 4 est une photographie d'un tissu du type "seersucker", obtenu conformément à l'invention.

La figure 5 est une photographie du tissu de la figure 4 ayant subit un calendrage.

La figure 6 est une vue de côté d'un métier à tisser fonctionnant dans une variante du procédé conforme à l'invention, destiné à réaliser des motifs en rayures sur un tissu.

La figure 7 est une photographie d'un échantillon de tissu obtenu grâce au métier à tisser de la figure 6.

The manner of carrying out the invention as well as the advantages which result therefrom will emerge clearly from the description of the embodiments which follow in which:

Figure 1 is a side view of a loom operating according to the method according to the invention, shown in its application for the production of fabrics of the "seersucker" type.

Figure 2 is a top view of the sheet at the characteristic area of the invention in which is caused the heating prior to weaving itself.

Figure 3 is a top view of the same area, but with a different distribution of the two series of chain son.

FIG. 4 is a photograph of a fabric of the "seersucker" type, obtained in accordance with the invention.

Figure 5 is a photograph of the fabric of Figure 4 having undergone calendering.

Figure 6 is a side view of a weaving loom operating in a variant of the method according to the invention, intended to produce striped patterns on a fabric.

FIG. 7 is a photograph of a sample of fabric obtained using the loom of FIG. 6.

Ways to realize the invention

As already said, the invention relates to a weaving process treating in a differentiated chain threads. It can have several applications, and in particular two main applications, namely the production of fabrics of the type "seersucker", which will be described first, as well as the realization of striped fabrics, which will be described in a second step.

First way of carrying out the invention

In this first application, the weaving process is intended to be applied to chain threads generally having a high elastic modulus.

This process can be implemented on a traditional weaving loom, equipped elements making it possible to ensure a heat treatment of the warp threads then that they undergo tensioning by the roll of the fabric of the loom to weave, and as the Applicant has described in patent FR 2,751,350.

Such a loom also includes special arrangements making it possible to produce the characteristic fabric of the invention.

Thus, as illustrated in FIG. 1, a loom present in the direction of route of the wire, a beam (1) mounted on a drum (2), on which are wound all parallel warp threads.

These warp threads (3), from the beam (1) are unwound to a wire roller (4) from which they take a direction substantially horizontal.

To cross the characteristic area of the invention described below, the wires of chain (3) pass on either side of two spurs of spurs (31, 32). After these spur rods (31, 32), they are brought together again in one tablecloth by the guides (5, 6). Then they are supported by beams (7, 8) including the object is to move up or down the different chain threads (3) to form the shed (9), and allow the insertion of the weft thread (16). The reference (15) indicates the opening point of the crowd.

After the heddles (7, 8), the chain threads meet at the point of facade (10) on which the comb (11) beats, after each re-opening of the crowd. From the point of shaping, the fabric (12) thus formed passes through different return rollers (13) to lead to the winding system (14).

As already said, the invention consists in heating only part of the wires of energized chain near the opening point of the crowd, to decrease their modulus of elasticity, and if necessary allow them to undergo, thanks to the action of loom, a jerky print just before weaving itself.

Thus, various means can be adapted to ensure this heating.

In the illustrated form, it is a heating pad (20) present over the entire width of all the warp threads, and which can come into contact with part of the web of warp threads, between the spindle strips (31, 32).

More specifically, it is a transverse heating element whose face lower is covered with a material with very high surface hardness and low friction rate to avoid any abrasion by the chain wires which would cause subsequent deterioration of the warp threads themselves.

It may especially be an anodized or chromed outer layer (24) or ceramic.

Obviously, the invention covers all types of heating of the skate, and in particular those using electrical energy, to the connection means (22) appropriate.

As already said, according to an essential characteristic of the invention, only one part of the chain son undergoes heat treatment due to the shoe.

Thus, as illustrated in Figure 1, downstream of the wire roller (4), the loom has at least one spanning rod (31) allowing the separation of the ply (30) in two series, namely a series (34) passing over the bar (31), and therefore intended to come close to the shoe (20).

In contrast, the other series (33) passes below the bar (31), and is therefore further from the shoe (20) than the series (34).

The two series (33) and (34) travel parallel paths until reaching to the second spine rod (32) marking the end of the zone of separation of two series (33, 34).

Depending on the distribution of the different beams forming the two series, a distribution is obtained inside the final fabric, of threads capable of undergoing shrinkage, and elongated and already fixed wires.

Figure 2 illustrates a distribution of these wires inside each of the series.

Thus, as illustrated diagrammatically, the series of wires traversing the area characteristic being distant from the skate, breaks up into several bundles (40, 42, 44) passing under the bars (31) and (32).

Conversely, the beams (41, 43, 45) pass them, over the bars (31, 32) and therefore have a route passing close to the skate.

In FIG. 2, the different beams (40, 45) have identical widths, which results in distortions distributed in a way on the final product approximately uniform according to a regular grid.

Conversely, the breakdown of the water table according to the diagram in Figure 3, in which the different beams (50, 55) all have different widths, induces a different distribution of effects on the finished fabric causing patterns individuals.

As provided in the document of the Applicant FR 2 751 350, the shoe can be associated with any advantageous device making it possible to avoid degradation or even fusion of the threads when the progression of the threads is stopped.

In addition, different types of heating can also be adopted.

In accordance with the process of the invention, a fabric was produced from warp yarn made of polyester, of a title of 50 decitex, with 36 strands, twisted to 1300 turns per meter, and having previously undergone a false twist step.

So this textured crepe warp yarn was woven with weft yarns also in polyester, 50 decitex, 36 strands and twisted at 750 turns per meter.

Using a heating pad to raise the temperature to near 220 ° C we obtained the fabric including a photographic reproduction constitutes FIG. 4. Such a tissue has multiple hollow and raised zones formed by a differentiated length of the wires and accentuated by the withdrawal differentiated from different areas of the fabric.

This withdrawal is further accentuated by the implementation of a subsequent treatment. free thermal such as scalding.

The effects obtained can still have a greater variety, making undergo an additional calendering or ironing step allowing to overwrite the different patterns, as shown in the photograph in Figure 5.

It appears from the above that the process according to the invention allows obtain fabrics with a particularly attractive and original appearance, with multiple raised and depressed areas, like other fabrics to seersucker.

Changing the width of each beam (40-45; 50-55) is a particularly easy to perform, which increases easy versatility of the process according to the invention.

Second way of carrying out the invention

As already said, the invention can also be advantageously implemented work to make striped fabrics, using the sublimation technique of dyes carried by a transfer paper. In this case, the trade used can be that illustrated in Figure 6 in which the web of warp threads (3) is unwound from known manner of its beam (2) passing over a set of detour rollers (4, 4 ').

In a known manner, after having crossed the characteristic zone of the invention intended to produce an impression, the chain enters frames comprising the heddles (7, 8), then in the threshing comb (11) which forms the stitch (10). The formed fabric (12) then passes over a detour roller (13) to be returned to a magazine roller (14).

The reference (15) designates the opening point of the crowd.

In a known manner, and as described in the aforementioned patent EP 0 461 048, incorporated below by reference, a reel (60) of transfer paper (61) carrying a appropriate pattern is brought into contact with the chain (3) possibly by pressing on the detour roller (4).

Just in the vicinity upstream of the opening point (15) of the crowd (19), a skate heater (63) capable of being moved up and down, comes heat fix the dye on the chain which advances slowly.

A detour bar (64) makes it possible to recover the spent transfer paper (65) on a roller (66), synchronized with the advance of the loom.

The different aspects concerning the heating means used and all the possible variants are identical to those already described in the patent EP 0 461 048 of the Applicant, corresponding to documents US 5,212,845 and US 5,377,509.

According to a characteristic of the present invention, the ply (3) of chain is separated into two parts (33, 34), so that only part of the wires of chains undergo the sublimation printing of the dyes present on the paper (61).

In practice, this separation is obtained through the use of two bars transverse (31, 32) placed between the detour roller (4), and the bars (5, 6) materializing the opening point (15) of the crowd.

These two bars (31, 32) arranged one after the other make it possible to shift the two series of wires (33, 34), and to maintain a spacing therebetween.

In this way, only the series (34) of wires passing near the shoe (63) and coming into contact with the paper (61) is printed.

The selection of the wires belonging to the series (34) coming into contact with the paper is carried out with complete freedom, which allows, as illustrated in FIGS. 2 or 3, to obtain either perfectly identical stripe patterns when the segments (40, 45) all have an equal or similar number of threads, or to obtain effects variables at will when the beams (50, 55) (see Figure 3) have very different numbers of wires.

As already said, the wires located at the end of each of the bundles, when pass in contact with the paper (61) in the area facing the pad (63), receive the sublimated dyes. It has been observed that the wires located at the end of each of the bundles receive more dyes than the wires located in the center of the bundle, it follows that when the printed threads are gathered with the warp threads of the series (33), an overcurrent of color is visible at the level of these particular wires.

The stripe thus obtained therefore has a particularly crimped effect. appreciable.

Multiple variations are, of course, possible using paper transfer with patterns which, combined with the scratch effect obtained in accordance with the method of the invention, multiply the visual effects.

One can in particular use transfer papers (61) which themselves a succession of longitudinal stripes. When the scratches on the transfer paper are arranged in such a way that their border between two adjacent stripes are printed on the series (34) of selected warp threads, the stripes as well obtained have at least two colors or even a mixture of the two colors when they are contiguous.

• d'obtenir des rayures parfaitement rectilignes et pouvant reproduire un motif d'une grande variété ;
• de modifier avec une grande facilité la dimension des rayures choisies, en fonctionnant avec une seule ensouple par la seule modification de la répartition des fils de chaíne devant recevoir l'impression.

It appears from the above that the process according to the invention has multiple advantages, and in particular allows:

• obtain perfectly straight stripes capable of reproducing a wide variety of patterns;
• to modify with great ease the size of the selected stripes, by operating with a single beam by the only modification of the distribution of the chain son to receive the impression.

The fabric according to the invention is particularly original, because it has perfectly straight stripes with borders limited to one single thread, while being able to present patterns of an extreme variety.

It is also possible to combine the two embossing effects and coloring of the stripes, to obtain a fabric of which the embossed portions are colored.

It goes without saying that the transposition of the invention to knitting looms chains would be done without difficulty for a person skilled in the art, and the invention covers so also the fabrics knitted on "chain loom" obtained on the same principle.

It appears from the above that the method according to the invention allows, by the simplicity of the means which it uses, a very great versatility, the realization economical and easy fabric of a very wide variety without modification particular of the simplest weaving loom.

Claims (8)

1. A process for obtaining a woven cloth in which

   a sheet of parallel warp yarns (3) is continuously unwound from a single warp beam (1) ;

   said sheet is made to pass over a back-rest roller (4);

   a shed (9) is formed by means of healds (7, 8), said shed being defined, in the direction of advance of the warp, at the entrance of the shed by an opening point (15) and on the other side by a fell point (10);

   a weft yarn (16) is inserted into the shed in the vicinity of the fell point (10) in order to form a cloth; and

   finally, the cloth thus formed is pulled uniformly and wound up;

   and in which, in the vicinity of the opening point of the shed a heating operation is carried out on the warp yarns (3) and then said warp yarns are cooled in the shed before they reach the healds (7, 8),
   characterized in that the heating operation is carried out only on a portion of the warp yarns.
2. The process as claimed in claim 1, characterized in that:

   downstream of the back-rest roller, the sheet is separated into two series of yarns (33, 34); and

   a gap is maintained between the two series of warp yarns (33, 34) in order to subject only one of the two series to the heating operation.
3. The process as claimed in either of claims 1 and 2, characterized in that the heating operation is carried out on the warp yarns at a temperature high enough to cause an elongation and a local reduction in the elastic modulus thereof.
4. The process as claimed in claim 3, characterized in that it furthermore includes a subsequent heat treatment step or a treatment in the free state.
5. The process as claimed in claim 4, characterized in that the step of treatment in the free state is a scalding step.
6. The process as claimed in one of claims 3 to 5, characterized in that it furthermore includes a calendering step.
7. The process as claimed in either of claims 1 and 2, characterized in that

   only that portion of the warp yarns which undergoes the heating operation brought into contact with a transfer paper (61) carrying dye patterns, which can be transferred onto the warp yarns (32) owing to the effect of said heating operation;

   said transfer paper (61) is made to run in a speed relationship with the speed of advance of the sheet of warp yarns;

   so that transfer of the dye pattern takes place only on just said portion (34) of the warp yarns.
8. The process as claimed in claim 7, characterized in that the transfer paper (61) has a pattern of parallel stripes in the direction of run of the paper and in that at least one of the boundaries of said bands is brought close to that portion of the warp yarns on which the printing takes place.

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