EP0452163B1 - Method for treating textile materials by high pressure jets - Google Patents

Description

The present invention relates to a method for treating textile articles or articles, produced from woven or knitted fabrics, the treatment being of the mechanical finishing type and intended to modify their structure, for example by increasing the volume, by improving the flexibility, by modifying their surface appearance.

There are very many mechanical finishes, in which various organs are used, said organs and their mode of action being chosen according to the desired goal: thistles, scraping rollers to give a fluffy appearance to a piece of yarns. fibers, fulling machine to give volume to the wool, vibrating carpet or other device for mechanically projecting the part onto an obstacle to improve dimensional stability, etc. In all of these techniques, the mechanical organs come into contact with the part textile and modify during this contact the structure that said piece had either after weaving or knitting or possibly after making the finished article, most often by a relative displacement of the constituent threads of the piece, or of staple fibers or continuous filaments composing said wires. In most cases this contact of the mechanical organs is accompanied by a certain degradation of the part by breaking of filaments or fibers. On the other hand, this contact between the parts and the mechanical member can lead to wear of the member and therefore a progressive evolution of the result obtained.

Yarn producers have proposed yarns made up of continuous filaments with adherent microfilaments, obtained by star or lamellar spinning. The pieces obtained by weaving or knitting such threads are then subjected to a treatment intended to individualize the microfilaments, so that said piece has the flexibility, the feel, the voluminosity corresponding to the unitary microfilaments.

This individualization of the microfilaments is carried out using suitable chemical treatments in which the matrix ensuring the bonding of the unitary microfilaments, or superficially the interlamellar surface is attacked. It is in particular a treatment with soda when the microfilaments are made of polyester.

Such chemical treatments have multiple drawbacks: it is difficult to perfectly control all the parameters in order to obtain a uniform treatment (duration of treatment, temperature, concentration of the bath); the part thus treated loses weight due to its partial dissolution; treatments are long and expensive.

In the remainder of the text, the general term "piece" will designate all the presentations of woven or knitted fabrics: fabric or knitted fabric which has fallen out of the trade and which is in the form of a strip of very long length, part cut from such a strip or made-up item.

The aim set by the applicant is to propose a simplified treatment of textile pieces which not only modifies their structure without causing breakage of continuous filaments in the constituent threads of the piece or of the treated article, but also constituent yarns being continuous filaments with adherent microfilaments, realizes the individualization of the microfilaments.

This object is perfectly achieved by the method of the invention. Said method consists in treating a textile piece, resting on a support grid, said piece being made up in whole or in part of continuous filament yarns with adherent microfilaments by the action of water jets at a pressure of at least 4.10.⁶Pa, by means of what the action of the water jets dissociates the microfilaments.

Admittedly, from documents EP.A.10.546 and EP.A.193.0378, treatments of textile parts are known, in which said parts are subjected to the action of jets of high pressure fluid.

In document EP.A.193.078, the action of the water jets aims to make the fibrous structure of a fabric of inorganic fibers more open for the reinforcement of resin, in particular for printed circuit boards.

In document EP.A.10.546 the action of the water jets is intended to give the fabric the satin appearance of a natural suede. The possibility is provided of using composite threads with adherent microfilaments, but in this case the fabric undergoes various treatments, prior to the action of the jets of fluid, and intended to individualize the microfilaments, relaxation in a water bath hot, drying, scraping, thermal fixing.

Thus the credit goes to the applicant for having demonstrated that the action of water jets at a pressure of at least 4.10⁶Pa was capable of dissociating the unitary microfilaments, in addition to the modification of the structure proper, without breaking of the microfilaments: the unitary microfilaments of the filaments are detached either from each other if it is a lamellar spinning or from the matrix if it is a star spinning.

The method of the invention makes it possible to obtain a completely reproducible effect, in the case of simple adjustments of the physical conditions: speed of the grid, pressure of the water jets, in particular.

Preferably, the support grid moves continuously under several ramps, each comprising a set of high-pressure water jet injection nozzles, the water pressure being identical or different from one ramp to another. Advantageously, the part is subjected to the action of jets at increasingly higher pressures.

For example, the running speed of the part being between 20 and 100 m / min, it is successively subjected to the action of four ramps of water jets at stepped pressures respectively of 4.10⁶ to 20.10⁶Pa.

Certain constituent threads of the part are for example threads composed of filaments with adherent microfilaments obtained by star spinning, each filament having a titer of approximately 2dtex and comprising from 6 to 8 unitary polyester microfilaments from 0.2 to 0.4dtex, assembled using a polyamide matrix.

• La figure 1 est une vue schématique de côté de l'installation de traitement,
• Les figures 2A et 2B sont des vues schématiques en perspective d'un filament à microfilaments adhérents en étoile avant traitement (fig. 2A) et après traitement (fig.2B),
• La figure 3 est une vue schématique en coupe transversale d'un filament à microfilaments adhérents sans matrice,
• La figure 4 est une vue schématique en coupe transversale d'un filament à microfilaments adhérents lamellaires.

Other advantages and characteristics of the invention will appear more clearly in the description which will be given of several treatments of textile parts by high pressure water jets, illustrated by the appended drawing in which:

• FIG. 1 is a schematic side view of the treatment installation,
• FIGS. 2A and 2B are schematic perspective views of a filament with adherent microfilaments in a star before treatment (FIG. 2A) and after treatment (FIG. 2B),
• FIG. 3 is a schematic view in cross section of a filament with adherent microfilaments without matrix,
• Figure 4 is a schematic cross-sectional view of a filament with adherent lamellar microfilaments.

The treatment installation 1 which will be described is suitable in particular for textile pieces, fabrics or knits, wound in the form of coils 2 of continuous strips. This installation 1 comprises a set of means carrying out the positioning and the transport of the part 3, namely from upstream to downstream a shaft 4, driven by a motor not shown, on which is fitted the coil 2, rollers 5 of tension, a support grid 6 consisting of an endless belt wound and stretched between two cylinders 7,8 driven at the same linear speed as the shaft 4, the part 3 resting on the upper part 6 a of the grid 6, and finally a detour roller 9 cooperating with a shaft 10 for winding the coil 11 made up of the part 3 treated.

For simplification, FIG. 1 shows only two ramps 12, 13 for injecting high pressure water. Each ramp is supplied by a pump 14.15 capable of working at adjustable pressures ranging from 4.10⁶Pa (40 bars) to more than 20.10⁶ Pa (200 bars). Each ramp 12, 13 comprises a plate pierced with a set of orifices serving as injection nozzles 16 distributed on the one hand over the entire useful width of the grid 6 at the rate of an orifice every 2 mm and of somewhere else on several rows, for example three rows have been shown in FIG. 1. The high pressure water leaving the injection nozzles 16 is in the form of extremely fine jets, having a diameter of the order of 100 to 150 micrometers.

Suction boxes 17, 18 are placed opposite the injection ramps 12, 13 under the upper part 6 a of the grid 6 while the ramps are located above this upper part 6 a , the nozzles 16 being directed perpendicular to the plane of said upper part 6 a and therefore to part 3.

The support grid 6 is a metallic grid of 100 mesh (that is to say of 100 meshes per inch) produced with wires of 200 micrometers in diameter.

A drying tunnel 19 is placed on the passage of the part 3 treated after the outlet cylinder 8 and before the detour roller 9.

A polyester fabric of about 130 g / m² was treated having as a warp thread a conventional thread making 90dtex, and comprising 136 continuous filaments, and as weft thread a continuous filament thread with adherent microfilaments obtained by star spinning. Such a wire is shown in Figure 2A. It comprises six unitary polyester microfilaments; each microfilament 20 has in cross section the shape of an orange quarter; the six microfilaments 20 are separated by a matrix 21 of polyamide having six radial branches 22 symmetrically distributed around the longitudinal axis 23. Each unitary microfilament 20 of polyester has a titration of between 0.2 and 0.4dtex.

The treatment of the above fabric was carried out at 20m / min, by passing under four injection ramps, the water being respectively at 6.10⁶Pa, 8.10⁶Pa, 20.10⁶Pa and 20.10⁶Pa.

After such a treatment, it is observed that the unitary microfilaments 20 have been detached from the matrix 21, under the impact of the water jets, as illustrated in FIG. 2B. But there is no degradation of either the microfilaments 20 or the matrix 21; the fabric therefore did not lose weight.

The combined action of the individualization of the unitary microfilaments 20 and of the relative displacement of said microfilaments 20 with respect to each other also due to the action of water jets gives the fabric very great flexibility and a very high clos. The clos corresponds to the distribution of filaments and microfilaments in relation to the volume of the tissue.

There are other types of son with adherent microfilaments, in particular those shown in FIGS. 3 and 4. In FIG. 3 a wire without core is shown, that is to say that the bonding matrix of the four microfilaments 24 in polyester is made up of four polyamide microfilaments 25 joined to two successive polyester microfilaments 24.

FIG. 4 shows a yarn of the lamellar type in which the polyester microfilaments 26 correspond to longitudinal sections of a filament of substantially circular section. The self-adhesion between the four microfilaments 26 is obtained from the fact that when spinning the four strips are joined only after a certain time of cooling of the polyester.

The textile pieces produced with adherent microfilament yarns as described above were treated on the installation 1. It was also noted that the microfilaments 24, 26 were individualized under the impact of the high pressure water jets, without degradation.

The invention is not limited to the treatments which have been described by way of nonlimiting examples but covers all the variants.

It is understood that the invention is based on the use of water jets at pressures of at least 4.10⁶ Pa (40 bars) to modify the structure of textile pieces, fabrics or knits, whose constituent threads are already assembled between them. This structural modification consists in the mechanical separation and the relative displacement of microfilaments which had, in the thread before treatment and during weaving or knitting, a certain adhesion.

Claims (6)

1. Process for treating a textile piece constituted wholly or partly by yarns of continuous filaments with adherent microfilaments, intended to separate said microfilaments, consisting in subjecting said piece, resting on a support screen, to the action of jets of water at a pressure of at least 4.10⁶Pa.
2. Process according to Claim 1, characterized in that the support screen (6) moving continuously, the piece (3) passes beneath a plurality of pipes (12, 13) spraying water at adjustable pressure.
3. Process according to Claim 2, characterized in that the speed of displacement is combined between 20 and 100 m/min and the piece (3) passes beneath at least four pipes spraying water at pressures stepped between 4.10⁶Pa and 20.10⁶Pa.
4. Process according to one of Claims 1 to 3, characterized in that the water jets have a diameter comprised between 100 and 150 micrometers.
5. Process according to Claim 1, characterized in that the continuous filaments with adherent microfilaments comprise six to eight unitary microfilaments of 0.2 to 0.4 dtex.
6. Process according to Claim 5, characterized in that the yarns of continuous filaments with adherent microfilaments being obtained by star spinning, the unitary microfilaments are of polyester and the matrix of polyamide.

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