CA2300583C - Process for manufacturing multisegmented filaments or fibres, as well as the resulting filaments or fibres and their resulting textile sheets - Google Patents

Abstract

The subject of the present invention is a process for the manufacture of multisegmented filaments or fibers and / or with composite structures, filaments or fibers and a textile surface thus obtained. Process characterized in that it consists in conveying the polymer material (s) (1, 1 '), under suitable rheological conditions, at the level of a die (2), then in extruding this or these polymer (s) through separate spinning or extrusion orifices (On, Om), but associated in one or more groupings to form one or more sets of at least two elementary filaments (3, 3 '), to then be assembled together, by contact adherent, the different elementary filaments (3, 3 ') coming from each grouping of orifices (On, Om), into a filament (4) with cross-segmented section by grouping, with a mixture of the phases limited or nonexistent, and, finally to stretch and consolidate the resulting filaments (4) before their treatment and / or subsequent manipulation (s), in particular for the production of fibers, spools of filaments, cables or nonwovens plies by direct route, for example.

Description

METHOD FOR MANUFACTURING MULTISEGMENTATED FILAMENTS OR FIBERS, THUS
AS RESULTING FILAMENTS OR FIBERS AND TEXTILE SURFACE
DESCRIPTION
The present invention relates to the field of textile products and their applications, more particularly the field of textile surfaces woven, knitted or nonwovens, and relates to a process for manufacturing a filament or of a multisegmented fiber, a filament or a fiber thus obtained, as well a textile surface formed of such filaments or fibers.
Numerous processes are already known for producing multisegmented filaments or fibers, as well as textile surfaces non-woven, and then reduce them by a suitable separation technique into filaments very weak titles. These multisegmented filaments or fibers are currently obtained in the form of monofilaments or monofibers in coextruding one or more thermoplastic polymeric materials or solution in a specific solvent, through compartmentalized die orifices or supplied with different polymers and shaped according to the segmentation and elementary filament shapes which are desired.
However, this coextrusion technique has a certain number of limitations and drawbacks.
Thus, the separation of multisegmented filaments into filaments elementary is often difficult to achieve and requires devices developing significant separation forces, particularly in the context of separation mechanical.
Furthermore, this separation is currently almost impossible to realize when the filaments or fibers consist of filaments or fibers elementals formed from the same polymer or polymers chemically compatible.
This difficulty in separating into elementary filaments results in particular from the mixture of the phases constituting the different filaments elementary between them, their junction taking place while the polymers constitutive are still in a miscible state.
In addition, the variety of forms and titles achievable by the technique current is limited, due to the necessary complexity of the circuits supply, low limits for spinning and extruding filaments or fibers fine titles, physical impossibilities resulting from coextrusion and difficulties in production and prohibitive costs of the necessary channels.

-2-Furthermore, it is not possible with the current technique to obtain complex exterior shapes with sharp outlines, such as edges, indentations or the like, the latter fading due to the properties rheological of polymers in the molten state or in the form of solution (s).
The present invention aims in particular to overcome the aforementioned drawbacks.
To this end, it relates to a process for manufacturing filaments or multisegmented fibers and / or with composite structures, in particular for textile surface, by extrusion or spinning of thermoplastic) polymers or solutions) of polymer (s), characterized in that it consists in conveying the or the polymeric materials, under suitable rheological conditions, at the level a die, then extrude this or these polymers) through spinning orifices or extrusion lines, but combined in one or more groups to form a or several sets of at least two elementary filaments, to be assembled then between them, by adherent contact, the different elementary filaments from of each grouping of orifices, in a filament with a cross-section divided by grouping, with a limited or nonexistent mixture of phases, and finally consolidate and stretch the resulting filaments before processing and / or subsequent handling (s), in particular for the production of fibers, spools of filaments, cables or nonwoven fabrics by direct mail, by examples.
The invention will be better understood, thanks to the description below, which relates to preferred embodiments, given by way of examples not limiting, and explained with reference to the appended schematic drawings, in which Figures 1 to 6 are top views of five variants of production of die plates according to the invention;
Figure 7 is a partial sectional view in side elevation of a portion of a sector according to the invention implemented in the context of manufacturing method according to (invention;
Figure 8 is a top view of the die portion shown in Figure 7, and, figuxe 9 is a partial sectional view in side elevation of a portion of the chain used in the process of manufacturing according to an alternative embodiment of the invention.
According to the invention, the process for manufacturing filaments or of multisegmented fibers and / or with composite structures, in particular for

-3-textile surface, consists in conveying the polymer material (s) 1, the, in suitable rheological conditions, at a level 2, then to be extruded this or these polymers) through separate On, Om extrusion or extrusion orifices, but associated in one or more G groups to form one or more sets of at least two elementary filaments 3, 3 ', to then be assembled Between them, by adherent contact, the different elementary filaments 3, 3 ′ originating of each group G of holes On, Om, in a filament 4 with section cross-segmented by group G, with a limited mixture of phases or nonexistent, and finally consolidate and stretch the resulting 4 filaments before their treatment and / or subsequent manipulation (s), in particular with a view to realisation of fibers, spools of filaments, cables or nonwoven webs direct, for example.
So unlike the state of the art coextrusion technique technique, in which the phases of the different components were put in contact in the spinning hole, unique for each filament or fiber crossover, while the phases are still miscible, the invention provides an extrusion by independent On, Om spinning orifices and the contact components from these orifices and forming the different filaments elementary 3, 3 ′, outside said wiring holes On, Om, while skins 5, 5 ′ delimiting the phases of said components have already formed and than the viscosities of the latter are already significantly different from that they were at the On, Om wiring ports.
We therefore end up with a multisegmented filament or fiber 4 whose cohesion results from adherent contact between interface zones of the different components still sufficiently plastic and adherent to provide a tacky surface bond, but simultaneously sufficient consolidated to substantially avoid any mixing of phases at the level of surfaces in contact.
The bonding forces existing between the different filaments or fibers elementary 3, 3 'will therefore be sufficient to maintain the structure Unit of ~
multisegmented filaments or fibers 4 during possible stages subsequent handling or processing (multisegmented filament or fiber) obviously having higher resistance to stresses than different elementary filaments taken separately), but nevertheless of a intensity limited promoting their subsequent separation, in particular by means mechanical.

-4-The spinning holes On, Om providing the elementary filaments 3, 3 'will generally consist of single opening orifices (opening full), not compartmentalized and not segmented, providing easy wiring.
However, depending on the type of filaments or fibers, and surface resulting textile, desired one or more of these On, Om orifices present a segmentation or compartmentalization, in particular in two compartments for example to produce bimetallic strips.
According to a first characteristic of the invention, represented in particular in FIGS. 7 and 9 of the appended drawings, the wiring holes On, Om of the same grouping G are arranged between them so that the bulb Bn or Bm of polymer material which forms at the outlet of each of these orifices We or Om during extrusion, is in contact with at least one Bn or Bm bulb form at the outlet of at least one other orifice, Om, of this same group G.
The conformation and dimensions of the bulbs Bn, Bm forming at the exit from the spinning orifices, and from which the elementary filaments 3, 3 ' are spun by stretch, will be determined by the shape and size of orifices, by the nature of the polymer (s) or solution (s) of polymers) extruded (s), as well as pressure, speed and conditions rheological extrusion and spinning, and consolidation conditions.
These latter parameters will therefore also to influence the bonding forces between the different elementary filaments 3, 3 '.
In accordance with an advantageous embodiment of the invention, each spinning opening On of a grouping G of spinning openings On, Om to round sections or substantially inscribed in a circle, check with at minus one other Om wiring orifice of this same group G, the following relation (1) 0.5x (Dn + Dm) / 2 <_d <_5x (Dn + Dm) / 2, (1) in which n ~ m, n varies from 1 to T and m varies from 1 to T o ~ 1 T is the total number of spinning orifices of group G, Dn is the diameter of the orifice of spinning On, Dm is the diameter of the wiring hole Om and d is the distance between the points On 'and Om' closest to the edges of the two wiring holes On and Om concerned (see Figure 8 of the accompanying drawings).
Preferably, each spinning opening On of a group G of wiring ports On, Om checks with at least one other orifice of spinning Om of this same group G, the following relation (2) 0.5x (Dn + Dm) / 2 <_d <_2x (Dn + Dm) / 2. (2)

-5-However, the shape of the sections, the dimensions of the sections and the relative arrangements of the On, Om wiring orifices of the same group G
can be determined according to the dimensions, conformation and of the desired properties for the multisegmented and / or composite filament 4 resulting the only condition to check being that each elementary filament 3, 3 ' are coming in adherent contact with at least one other elementary filament 3 ′, 3.
Thus, thanks to the invention, it will be easily possible to obtain complex and tortured outer shapes for multisegmented filaments 4, while using die plates 2 provided with spinning holes On, Om of simple form and easy to carry out industrially.
Similarly, due to the junction of the elementary filaments 3, 3 'after formation of outer skins S, 5 ', the details of the contours of said different filaments or elementary fibers 3, 3 'of simple shapes, associated with them to form a filament or fiber 4 with complex section, will not have trend to fade, but will rather retain a clear definition corresponding to the shape of the corresponding On, Om wiring holes, from which a shape results of clean section of filament or fiber 4 after cooling, even in the event of of section with very complex configuration.
According to another characteristic of the invention, and with a view to adjusting the cohesion forces of the multisegmented filament 4, provision may be made for to differ, continuously or intermittently, the adherent contact between at least two elementary filaments 3, 3 ′ coming from spinning holes On, Om close to a even group G.
Thus, as shown in Figure 9 of the accompanying drawings, the shape of the bulb Bn, Bm of polymer material which forms at the outlet of each of the holes On, Om spinning during extrusion, can be altered for at least one of the orifices of a group G at its potential contact area with the or the bulbs Bm formed at the outlet of at least one wiring hole Om neighbor, from same group G, to defer or offset the adherent contact between the two elementary filaments 3, 3 'resulting.
To carry out the above operation, training may be provided a gas blade or the installation of a plate or a tapered tip between the On and Om ports concerned.
Of course, the wiring holes On, Om of the same group G may, depending in particular on the properties and the nature of the water table resultant nonwoven sought, either be fed with the same material

-6-polymer 1, or be supplied with at least two polymer materials different 1, the.
The subject of the present invention is also, as shown by the Figures 1 to 9 of the accompanying drawings, a die plate 2 for setting artwork the manufacturing process described above, characterized in that it has a plurality of On, Om wiring ports grouped into one or more groupings G, each spinning opening On of a grouping G of spinning openings On, Om, preferably with round sections or substantially inscribed in a circle, checking with at least one other wiring orifice Om of this same group G, the relation (1) mentioned previously or, preferentially, the relation (2) indicated above.
The manufacturing process according to the invention therefore allows to obtain a multisegmented filament or fiber made up of several elementary filaments or fibers (3, 3 ') secured to each other, at less two by two and with predetermined bonding forces, by contact member longitudinal at the level of their skins (5, 5 ') without mixing of the phases respective or with a limited mixture of phases.
The shapes of the die plates shown in Figures 1 to 6 the accompanying drawings illustrate, by way of non-limiting examples, the possibilities of making multisegmented filaments 4 by means of the process of manufacturing according to the invention.
Thus, the die plate 2 of FIG. 1 will make it possible to produce a filament 4 three-lobed, that of FIGS. 2A and 2B a filament 4 in the form of a ribbon or of film sectionable longitudinally, that of FIG. 3 a filament 4 in form daisy, that of Figure 4 a filament in the form of a hollow tube, that of the FIG. 5 a filament 4 of the bimetal type (in which the two filaments elementary 3 and 3 'can be formed with the same polymer or with two polymers and that of FIG. 6 a filament 4 formed by the intersection of of them hollow tubes of different diameters and formed from elementary filaments 3, 3 ' of different titles.
Note that the structure of the filament 4 obtained with the plate of die 2 of FIG. 3 will allow, for example, to produce filaments elementary 3 ′ in a polymer difficult to extrude and / or to process, for of a central elementary filament 3 as a tutor, the latter being made in a polymer easily exti ~ udable and able to undergo without damage the treatments consecutive.

_7_ Finally, the present invention also relates to a textile sheet, in particular a nonwoven web produced directly, characterized in that that it is made, at least in part, using multisegmented filaments obtained through the manufacturing process described above.
According to a characteristic of (invention, this sheet is advantageously, after training, at least subjected to a treatment aimed at fractionate and separate, in particular by mechanical or hydraulic action, at least part, and preferably all, of the filaments crossover 4 in elementary filaments 3, 3 '.
In order to illustrate further (invention, two below will be described nonlimiting examples of embodiment.
Example 1 A sheet of mass bisected continuous filaments is produced surface area 110 g / mz (NFG 3 $ 013) according to a process similar to that described in French Patent No. 7,420,254.
The configuration of the filaments making up the surface is based on a bimetal strip made of 100% PES with a 1.2 dTex title before separation (Figure 10: view in cross section of these filaments).
The polymer (POLYESTER) used has the characteristics following Nature polyethylene terephthalate Ti02 0.4%
Melting point 256 ° C
Melted viscosity 210 Pa.s at 290 ° C
Type and Origin type 20 from Hoechst Extrusion spinning conditions Drying is carried out in dry air with a dew point of -40 ° C and a residence time of 3 hours at 170 ° C. and the supply of the extruder is performed under a nitrogen atmosphere.
The spinning unit is circular and equipped with a die plate composed of 240 groups of two capillaries (orifices), 0.2 mm in diameter and 0.4 mm high 0.15 mm apart.
The polymer melting-extrusion temperature is 295 ° C and the spinning speed is around 4000 m / min and the throughput by grouping of 0.5 g / min (0.25 g / min / capillary).

_G_ Consolidation - Binding The surface produced undergoes (four times) a hydraulic bonding under jets at 225 bars (twice per side) at a speed of 35 m / min using nozzles 130 microns. The initial 1.2 dTex filaments are split in two parts identical to 0.6 dTex.
Features ~ taments Title (DIN 53812): 1.2 dTex Tnacit: 27cN / Tex Allon had: 78%

Product features Dynamometry: Charge SL 350 N / 5cm Algt SL
56%

Load ST 300 N / 5cm Algt ST
62%

Tear (NFG07146) SL 35 N ST 55 N

Withdrawal (180 / 5mn) SL -1.8% ST -2.1 %

Example 2 A web of continuous filaments, of surface mass, is produced 130 g / mz.
The configuration of the filaments making up the surface is based on a three-lobed distribution from three capillaries belonging to the same grouping (Figure 11: cross-sectional view of these filaments). The three capillaries of the same supply orifice are arranged along the vertices of an equilateral triangle of side 0.4 mm. The diameter of a capillary is d =
0.25 mm, its height Zd, the distance between two capillaries being 0.15 mm.
The polymer used and the extrusion / spinning conditions are identical to those of Example 1.
The flow per group is 0.66 g / min (3 x 022 g) and the speed of spinning / drawing is about 4,500 m / min, producing a filament of 1.5 dTex.
Consolidation-fixing The surface undergoes double-sided needling with 200 perforations per cm2 using 40 RB gauge needles in 12 mm penetration.

_G_ Features Features filaments produced Title 1,5 dTex Charge SL 490 N / Scm ST 370 N / Scm Tnacit 3lcN / Tex ElongationSL 60% ST 70%

Elongation 78%

Finishing-Application The product is then impregnated using a styrene butadiene resin S styrene at the rate of a deposit of 480 g / m2, then calendered (calibrated). The final product is intended for shoe buttresses.
Although the invention has been described more precisely in relation to hot melt extrusion of polymers, it applies also dry spinning processes (solvent (s) + polymers): extrusion with evaporation solvent] and wet spinning processes (solvent (s) + polymers) with Faculty in solvent bath of the solvent].
Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Changes remain possible, in particular from the point of view of the constitution of the various elements or by 1 S substitution of technical equivalents, without however leaving the field of protection of the invention.

Claims (13)

1) Process for manufacturing filaments or fibers crossover and / or with composite structures, by extrusion or spinning of thermoplastic polymer (s) or solution (s) polymer (s), characterized in that it consists in conveying the material (s) polymers (1, 1 '), under suitable pedigree conditions, at the level of a die (2), then to extrude this or these polymer (s) through orifices of spinning or extrusion (O n, O m) separated, but associated in one or more groupings (G) to form one or more sets of at least two elementary filaments (3, 3 '), then to assemble them, by adhesive contact, the different filaments elementary (3, 3 ') from each group (G) of orifices (O n, O m), in a filament (4) with cross-segmented section by group (G), with a mixture of phases limited or nonexistent, and finally to consolidate and stretch the filaments (4) results before their subsequent treatment and / or handling and, in addition, the spinning orifices (O n, O m) of the same group (G) are arranged between them such so that the bulb (B n or B m) of polymeric material which forms at the everyone's exit of these orifices (O n or O m) during extrusion, is in contact with at least a bulb (B n or B m) formed at the outlet of at least one other orifice (O n, O m) of the same group (G). 2) Manufacturing method according to claim 1, characterized in that each spinning orifice (O n) of a group (G) of spinning orifices (O n, O m) with substantially inscribed round sections in one circle, check with at least one other wiring hole (O m) of the same grouping (G), the following relation:
0.5x (D n + D m) / 2 <= d <= 5x (D n + D n,) / 2, in which n ~ m, n varies from 1 to T and m varies from 1 to T where T is the total number of the group's spinning orifices (G), D n is the diameter of the orifice of spinning (O n), D m is the diameter of the spinning hole (O m) and d is the distance separating them points (O n 'and O m') closest to the edges of the two orifices of spinning (O n and O m) concerned. 3) Manufacturing method according to claim 2, characterized in that that each spinning orifice (O n) of a grouping (G) of spinning orifices (O
not, O m) check with at least one other wiring hole (O m) of the same grouping (G), the following relation:
0.5x (D n + D m) / 2 <= d <= 2 x (D n + D m) / 2. 4) Manufacturing method according to any one of claims 1 to 3, characterized in that the shape of the sections, the dimensions of the sections and the relative arrangements of the wiring orifices (O n, O m) of the same group (G) are determined according to dimensions, conformation and properties desired for the multisegmented and / or composite filament (4) resulting. 5) manufacturing method according to any one of claims 1 to 4, characterized in that the spinning orifices (O n, O m) of the same group (G) are supplied with the same polymeric material (1). 6) manufacturing method according to any one of claims 1 to 4, characterized in that the spinning orifices (O n, O m) of the same group (G) are supplied with at least two different polymeric materials (1, 1 '). 7) manufacturing method according to any one of claims 1 to 6, characterized in that it consists in differing, continuously or intermittent, the adherent contact between at least two elementary filaments (3, 3 ') from the spinning orifices (O n, O m) adjacent to the same group (G). 8) manufacturing method according to claim 7, characterized in that that the shape of the bulb (B n, B m) of polymer material which forms at the outlet of each of the spinning orifices (O n, O m) during the extrusion, is altered to at minus one of the orifices (O n) of a group (G) at its area of contact potential with the bulb (s) (B m) formed at the outlet of at least one orifice wiring (O m) near the same grouping (G), to delay or shift the contact adherent between the two elementary filaments (3, 3 ') resulting. 9) Die plate for the implementation of the manufacture according to any one of claims 1 to 8, characterized in that that it comprises a plurality of spinning orifices (O n, O m) grouped in one or several groupings (G), each spinning orifice (O n) of a grouping (G) spinning orifices (O n, O m) with round or substantially inscribed sections in one circle, checking with at least one other wiring hole (O m) of the same grouping (G), the following relation:
0.5 x (D n + D m) / 2 <= d <= 5 x (D n + D m) / 2, in which :

n ~ m, varies. from 1 to T and m varies from 1 to T where T is the total number, of the group's spinning orifices (G), D n is the diameter of the orifice of spinning (O n), D m is the diameter of the spinning hole (O m) and d is the distance separating them points (O n 'and O m') closest to the edges of the two orifices of spinning (O n and O m) concerned. 10) die plate according to claim 9, characterized in that each spinning orifice (O n) of a grouping (G) of spinning orifices (O n, O m) checks with at least one other wiring hole (O m) of this same group (G), the following relationship:
0.5x (D n + D m) / 2 <= d <= 2 x (D n + D m) / 2. 11) Filament or multisegmented fiber obtained by means of the manufacturing method according to any one of claims 1 to 9 and made up of several elementary filaments or fibers (3, 3 ') integral (s) between them (them), at least two by two, by longitudinal adherent contact to the level of their skins (5.5) without mixing the respective phases or with a limited mixing of phases. 12) Textile tablecloth, characterized in that it is made, at least in part, using multisegmented filaments (4) obtained through the manufacturing process according to any one of claims 1 to 19. 13) textile tablecloth according to claim 12, characterized in that, after training, it is at least subjected to a treatment aiming to separate, in particular by physical or chemical action, at least one part, and multisegmented filaments (4) into filaments elementary (3, 3).