FR2494311A1 - TWISTED YARN, ITS MANUFACTURING METHOD AND ITS APPLICATIONS - Google Patents

Abstract

THE TWISTED WIRE HAS A CONNECTING WIRE HAVING A MELTING POINT LESS THAN 155C AND AN ELONGATION AT THE BREAKING OF MORE THAN 25. THIS WIRE HAS TO BOND TO THE OTHER COMPONENTS OF THE TWISTS, AT LEAST UNDER PRESSURE. THESE COPOLYAMIDE THREADS, KNOWN AS THE "SEPARATION THREADS" PRESENT, WHEN USED AS LINKING WIRES, IMPORTANT PROPERTIES THAT ARE ONLY EFFECTIVE UNDER WELL-DETERMINED CONDITIONS, PARTICULARLY WHEN THERMAL TREATMENT IS SUBJECT AT A TEMPERATURE BETWEEN 70 AND 155C, THIS HEAT TREATMENT INCLUDING, PREFERABLY AT LEAST ONE INTERMEDIATE EVACUATION, AND DURING AT LEAST 30 MINUTES, FOR EXAMPLE BETWEEN 50 AND 140 MINUTES, THE OPERATION PERFORMING IN PARTICULAR, IN AN AUTOCLAVE. IN THIS REGARD, IT IS VERY IMPORTANT THAT THE HEAT TREATMENT IS EXECUTED ON A STRETCH TWIST, PARTICULARLY ON A STRETCH TWIST UNTIL IT'S LIMIT OF TENSILE STRENGTH.

Description

2 494311

  The subject of the present invention is a plied yarn comprising at least one connecting thread made of a synthetic material extrudable by a die, as well as a method of manufacturing and applying such a plied yarn in the weaving and production industries. knitted fabrics and hosiery In the process of manufacturing a traditional endless twisted yarn for sewing, one produces, according to the desired final title (that is to say according to the weight in grams per 9000 m, a single plied yarn, with a multifilament (composed of multiple fibrils) by subjecting it to a twist S with a determined number of turns per meter, depending on the nature of the material and the

title.

  This can advantageously be carried out on a twisting machine with overlapping spools (after having previously carried out a transfer rewinding) or on a ring twisting machine (twisting-doubling machine), directly from the spinning reels. More recently, this method has also been used to

  production of sewing thread on double twist twists.

  Then, one proceeds to the assembly of two or more endless threads having previously undergone a twist S by a twist Z using the number of twists per meter appropriate according to the title and the number of elementary threads composing the plied yarn. This operation is generally carried out on a loom to be doubled, but could also be carried out according to the prior doubling process on twisting machines with overlapping spools.

or double twist.

  Whether natural or synthetic yarns, the twisting must

  necessarily be followed by a fixing operation.

  For example, for silk, whether synthetic or

  natural, we proceed with a steam treatment of the coils of the twist-

  deuse in an autoclave. The temperature and duration of this treatment are

  depending on the number of turns per meter of the plied yarn. In general, this temperature

  erection is between 40 and 650C, the duration of treatment (evacuation and

  rization) being approximately 40 minutes. In the jargon of the profession, we call

  this treatment the "calming" or "tranquilization" of the plied yarn.

  It is different with synthetic fibers such as Nylon and polyester. During the manufacture of the sewing threads, these two groups of fibers are subjected to a drawing and heat setting treatment. At this

  Finally, two methods are generally used.

  In the first, the sewing thread is wound with a certain tension (pre-stretching), depending on the title and the nature of the material, on a fixing drum, then this material is subjected to heat-fixing in a

  autoclave (Nylon) or in an electric oven (polyester).

  For Nylon, the treatment temperature is around 100 to 1400C and the treatment time varies between 80 and 130 minutes, while for polyesters the temperature is between 160 and 2000 C and the duration between

and 140 minutes.

  The second process differs from the first in that the stretching and the heat setting are carried out in a single operation (continuous process), the stretching, the temperature and the treatment time being a function of the title, of the nature

matter and speed.

  The stretching and the thermofixation result in orienting longitudi-

  nally the chains of atoms forming the plied threads.

  In addition, these operations have the result, depending on the treatment method, of influencing the final strength, the final shrinkage, the final elongation and the dyeing affinity of the resulting sewing thread, by calming the latter.

same time.

  These procedures for manufacturing sewing threads made of staple or chopped fibers, whether natural or synthetic, are only slightly. different from the procedures used for production

continuous wires.

  Thus, after spinning, the staple fibers are produced (synthetic chopped fibers) or, in the case of certain natural yarns, the staple fibers are produced, then these staple fibers are subjected to a torsion S with a determined number of turns

  per meter (depending on the title and the intended application).

  For this purpose, cotton spinning processes (three-cylinder process) and the schappe spinning process are generally used. Initially,

  the spinning process used is determined by the nature of the thread (silk, cotton).

  Today, these two spinning processes are used for staple fibers, which are known, for example, under the names of polyesters.

  spun by the schappe or cotton process.

  Thus instead of the production of the original twisted yarn in the case of endless yarns, the torsion S is used for the manufacture of discontinuous twisted yarn. The remaining methods differ from the previous ones only in that before the final twist, we submit all the twisted yarns, after the last step of

  manufacturing, a "gassing" (roasting of protruding fibers).

  It should also be mentioned that the threads are subjected to sewing

  made of high quality cotton, instead of fastening, for additional treatment

  mercerization, which has the effect of increasing its resistance by about

  ron 8 to 10%, it also contributes to improving the cleanliness of the thread.

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  In the process for producing core yarns, one or more multi-wire or single-wire, preferably polyester, is wound around a discontinuous wire

  natural or synthetic. To this end, the traditional ring loom is used.

  tional. When the surrounding threads called "covering" are for example in

  cotton and polyester core yarn, this stretching and heat setting treatment

  tion of the core wire can be made before winding the outer wires. As regards the subsequent treatments for improving plied yarns for sewing, such as dyeing, smoothing and blending, they are not directly related to the present invention and will not be

  therefore not described in more detail.

  The tendency to untwist traditional twists, in particular twists, is particularly troublesome with all natural twists for sewing, whether discontinuous or continuous threads, for example silk, cotton or linen. This results, when using the thread, a reduced solidity of the seams of the product, as well as difficulties in threading the thread into the eye of the needle. In addition, it becomes more difficult

to cut the end of the wire.

  In addition, the tendency to residual torsion is reflected, in particular

  bind in the case of endless plies of polyamide or polyester by unpleasant phenomena. Thus when sewing leather, mattress fabrics, seat belts, etc., torsion is subjected to pressures such that a retrograde torsion is inevitable. This results in a twist in the sewing thread and finally in the formation of

  knots, which inevitably results in breakage of the thread, deterioration

  ration of the needle plate, and ultimately leads to discards.

  Furthermore, the tendency to form buttons poses one of the most serious problems in the use of sewing threads with staple or continuous gimped fibers. Thus in the case of sewing threads based on staple fibers, these fibers, when they are insufficiently bonded, accumulate around the eye of the needle and lead to a rupture of the latter or of the thread. In the case of gimped sewing threads, the greatest danger lies in the repression of the gimping, which also results in the formation of pimples (thickenings) around the eye of the needle, which generally results in rupture of the thread or needle itself. Now, all the processes for making plied yarns for sewing

  are affected, to a greater or lesser degree, by the above drawbacks.

  The cause is an insufficient bond between the various components

devious.

  There is a method for manufacturing a bundle of fibers of a thermoplastic material in which the wires of the bundle are juxtaposed and there is provided under these wires, at least one connecting wire of a thermoplastic material, after which this bundle of fibers is subjected a treatment at a relatively high temperature which has the effect of melting the connecting wire, which thus fills the gaps between the wires forming the bundle. In this method, the bundle of wires is subjected to the heat treatment without tension, so that it is not sealed externally. As a result, the material of the molten connecting wire can escape from the fiber bundle and form around it a rough surface, slowing down subsequent treatments. Consequently, these threads cannot be used for sewing, for example. Added to this is a structure analogous to a wire and therefore completely inflexible.

(DE-AS 2 204 119).

  A method is also known in which the thermoplastic wire is surrounded or wrapped. So this wire stays straight in the center of the beam

  fiber as a co-carrier component.

  After this twisting or wrapping, this textile product is subjected to a heat treatment which has the effect of producing a connection between the surrounding and the core, that is to say with the thermoplastic central thread, without however modifying the section of the thermoplastic core wire. Thus, by the fixing between the components of the plied and the individual particles of plastic material, no connection is made, because among other things, the pressures and the corresponding fixing temperatures are lacking. This known process involves the use of a relatively large thermoplastic wire. It follows that, due to its very high coefficient of expansion (5-10 times greater than that of polyamide 66 for example), this yarn cannot be used in certain fields. A fixation, that is to say a control of the elongation is not possible with this process and with the resulting product. Consequently, such a wire cannot be used as a

  sew for clothes, etc ... (US-PS-2,313,058).

  The present invention has set itself the aim of producing a plied yarn in which an optimal and permanent connection is made between the various components, without however affecting the flexibility of the resulting ply. This result is obtained in the plied yarn according to the invention, which is characterized in that the connecting yarn has a melting point of less than 1550 C and an elongation at break of more than 25%, and in that it achieves , at least under pressure, an adhesive bond with the various components of the ply. Other characteristics and advantages of the invention will emerge from

  the description which will be given below only by way of example in no way

  limiting, with reference to the appended drawings in which: - Figure 1 is a very schematic representation of a twisting machine with overlapping spools to twist the modified nylon thread with the central connecting thread - Figure 2 schematically represents the section of a thread semi-finished twisted - Figure 3 is a schematic representation of a finishing twister - Figure 4 shows the section of a finished twisted yarn, before the bonding step; and, - Figure 5 shows the section of a plied yarn according to Figure 4 after

the linking step.

  As connecting threads between the various components of the ply, threads manufactured by the "Emser-Werken" are used. These threads consist of a copolymer composed of at least 3 polyamides, as described in detail,

  for example in U.S. Patent No. 4,225,699.

  These copolyamide yarns are known by the designation "separation yarns", and exhibit, when used as connecting yarns, interesting properties which however cannot be developed

  only under specific conditions (as explained below).

  In all techniques for the production of plied yarns for sewing, care should be taken to ensure that after the twisting, the connecting thread is as close as possible to the center of the resulting thread. This result is obtained by appropriate input voltages, as specified in embodiments 1 and 2 below. (An exception to this is the wrapping process

  and entourage in which these conditions are imposed by the procedure).

  Example 1 We will describe below the process for manufacturing an endless sewing thread no 8/3 in Nylon 6.6. and the connection between the components of this yarn and a copolyamide yarn whose melting point is 1100 C. Fields of application: the leather, mattress,

  upholstery for furniture and belts.

  For the production of the initial plied yarn, a loom with superimposed coils 1 (FIG. 1) is used operating with two parallel multi-threads of 550 dtex, for example with nylon 6.6 threads. having a resistance A and a parallel multi-thread of 78 dtex B with 250-300 twists per minute, these wires

  unwinding from reels 3, 4 and 5 and being twisted together in the direction

  tion S, the input voltages in the torsion mechanism 7 should not exceed for wires of 550 dtex 0.02 grams per dtex. On the other hand, the input voltage of the connecting wire B into the torsion mechanism 7 must not be less than 0.18 grams per dtex. These conditions are imposed by better placement of the wire.

  link B during the twist between the two wires A of 550 dtex (figure 2).

  With the initial or final twist, one twists, depending on the final title sought, a multifoly or a monofilament of copolyamides or a yarn of copolyesters which represents a fraction of between 0.5 and 15% of the final

that connecting wire.

  For the manufacture of the final twist, the three previous AAB twists are then placed on a twister similar to that of FIG. 1 and a Z twist is carried out from 150 to 200 turns per meter to obtain the twist

  final C on a reel 8 (Figures 3,4).

  We then rewind the finished plied figure of 4 on the drum of a

  parallel drawing machine operating with a tension of 600 to 1100 grams.

  Then, the sewing thread wound on the drum is treated in an autoclave, operating with a steam temperature of between 110 and

  1400C for 80 to 140 minutes with one or more intermediate evacuations

  diaries. This operation results in the longitudinal orientation of the

fiber atom chains.

  At the same time the connection between the various components A and B of the wire takes place. The same results could be obtained with

  the continuous fixation procedure described (Figure 5).

  All other refining or wire improvement operations

  sewing is carried out using current methods.

Example 2

  Production of plied yarn for sewing no 40/3 is carried out

  essentially as in embodiment 1.

  We operate on a twisting machine with superimposed coils, using a parallel 235 dtex multifilament made of Nylon 6.6 with great resistance, and operating a torsion of 530 to 560 turns per meter in the direction S (initial twists). We then assemble by twisting three initial threads of this kind and a 44 dtex bonding multi-thread with a protective twist, on a twisting machine with superimposed coils by twisting 360 to 390 turns per meter in the direction Z The input voltages in the twisting mechanism must be respected: for the 235 dtex wire, the tension must not exceed 0.025 grams per dtex and for the 44 dtex connecting wire, the tension

  input should not be less than 0.25 gram.

  With regard to the fixing and bonding stretching operations, as well as the other refining operations, the operation is carried out exactly as in

Example 1.

  The best quality cotton (long fibers) is used for cotton sewing threads. The spinning takes place on spinning machines

three-cylinder cotton.

  For sewing threads with synthetic staple fibers, we

  forms the endless wire into chopped discontinuous wires.

  In principle, there are two processes for the production of plied yarns for sewing staple fibers which make it possible to manufacture the products according to the invention:

  In the first, the continuous threads are transformed into disconnected fibers.

  chopped tin for the production of connecting wires. In this case, care should be taken that the chopped connecting threads are 30 to 40% shorter than the staple fibers to be tied (in order to respect the character

sons).

  Then, the staple fibers to be bound (cotton, polyester, etc.) are homogeneously mixed with the chopped connecting fibers in the

  proportion of 0.5, 15% of binding fibers.

  In the second possible manufacturing process for staple fibers or chopped fibers for the production of plied yarns for sewing, the procedure is as in the second example 2 up to the paragraph corresponding to the manufacture of the finished plied yarns, then we proceed to the joint twisting of an endless connecting wire having the corresponding thermal properties,

in the corresponding report.

  All other treatments remain the same as those described in

example 3.

Example 3

  On a cotton spinning loom (three-cylinder loom), a No. 56 cotton is spun with 4% chopped connecting fibers of modified nylon, melting point 1100C, using 600 to 750 turns per meter in direction S. Two of these threads are assembled on a doubling-twisting machine operating with 20 Z twists per meter. One then proceeds to a twist of such a doubled assembly on a twisted Hamel loom by operating with 600 to 700 revolutions per meter in the direction Z. One then proceeds to gassing, for example on a Mettler gas machine heated to propane or electric, operating at a running speed of 700 meters per minute. Mercerization can advantageously be eliminated because the bonding of the discontiIes fibers itself results in an increase in resistance. The bonding procedure is carried out, in the case of cotton sewing threads, in autoclaves heated to 1200C with one or more outlets,

  the duration on the gassing coils being 50 to 110 minutes.

  For the remaining procedures, reference should be made to Example 1.

  The production of plied yarns for sewing staple (or chopped) fibers based on synthetic material corresponds to the production of plied yarns for sewing in cotton, with the necessary thermal and technical modifications. Twists for cotton sewing, produced according to the process of the invention, require in all cases a two-step dyeing with a single bath, which is not necessary in the case of twists of staple fibers

  synthetics, when judicious choice of thread (Nylon or polyester).

  For the production of plied sewing threads comprising a core or central thread, it is possible, just as in the case of the production of plied threads

  discontinuous, use two methods to obtain the product according to the invention.

  The first process emerges from the paragraph concerning plied yarns for

sewing in staple fibers.

  In the case of the second possible method, a twisted core wire (single or multiple) is added for the wrapping procedure.

  link whose title depends on the desired final title.

  Then, a bonding step is carried out which is carried out under tension in an autoclave or in an electric oven, depending on the nature of the covering thread. It should also be mentioned that in the case of wrapped twisted sewing threads, which are produced on twisted hollow spindle looms,

uses the same processes.

  The following technical bonding conditions must be observed: To obtain an optimal bonding of the various components, the heat treatment of the plies must be carried out under a voltage as high as possible. This tension must be sufficient for the various components of the ply to surround the connection wire practically in a hermetic manner, without however resulting in other drawbacks, such as a leakage of the liquefied connection wire. Moreover, this tightness is influenced by the number of turns per meter (initial plied and finished plied). A correct number of turns per meter furthermore avoids an undesirable bond between the individual fibrils of the plied components, a bond which is harmful to the

  softness and flexibility of the finished twist.

  So we see that in these twists, the connecting wire forms what is commonly called when it comes to cables a "core" which, as the number of turns increases, is more and more enclosed inaccessible from the outside. The number of turns must be sufficient so that even during the heat treatment of the wire, during which the connecting wire melts, no fraction of the material of the latter can escape to the outside and

gain the surface of the wire.

  To this end, as shown by extensive tests, it may be advantageous to stretch the plied yarn as much as possible during winding on the

fixing drum.

  With regard to wrapped and other twisted yarns, it is advisable to proceed as described above, respecting the modifications

imposed by the procedure.

  In the case of twisted continuous fibers provided with a chopped fiber connecting thread, the chopped connecting fibers are washed away

  present on the surface of the yarn for dyeing.

  For the connection, any wire which is made of a plastic material which can be spun can be used, provided that its elongation at break is greater than 25%, for example between 30 and 50%, of. preferably between and 40% and that its melting point is, depending on the application, between

  and 1550 C. In addition, such a wire must be capable - at least under pressure -

  to stick to other textile threads.

  The connecting threads in copolyamides, that is to say the "separating threads

  tion of Ems "are binding materials with these properties.

  In addition, their high extensibilities have a very favorable influence on the flexibility of the finished ply. In addition, these connecting threads have the advantageous property of not sticking to other threads, in the molten state only under pressure, unlike other known separation or bonding threads formed from other copolyamide compounds. which, in the liquefied state, form a sticky mass

  which attaches to anything, without pressure. The connecting wires in copolya-

  mides suitable for use (Ems separation threads) have the following thermal properties, depending on the nature of the threads: - Melting point when using plied sewing threads

  with natural threads between 70 and 90 c.

  - Melting point when using twisted sewing threads comprising nylon threads between 105 and 140 C. - Melting point when using for the production of threads

  twisted sewing with polyester threads between 140 and 1550C.

  In these threads, these are filaments constituted by a copolyamide

  composed of at least 3 saturated and unbranched monomers, statistically distributed

  polyamide forming. This copolyamide has an average proportion of amides of 1-CONH- for 6.4 to 7.4 -CH 2- (or 1 -CH2- for 0.156 to 0.135 -CONH-). In this copolyamide, each monomer component is present in a molar proportion of between 10 and 60% relative to the molar sum of all the monomer components. The sum of the molar percentages of all the monomer components is equal to 100. The threads of this material have melting points below 1550 C. In addition to the great advantages of the plied threads according to the invention, for example for sewing, there should be retained the essential advantage according to the plied products according to the invention can be manufactured on all traditional plied yarn production facilities without significant modification. We propose to indicate below the different groups of twisted threads and their fields of application: 1. Twisted thread for sewing based on endless thread made of natural fibers,

artificial and synthetic.

  2. Twisted thread to sew in staple fibers (long fibers and fibers

  of spun cotton) into natural, artificial and synthetic fibers.

  3. Twisted gimped sewing thread (twisted for center thread sewing) in

  natural, artificial and synthetic fibers.

  4. Twisted yarn in natural, artificial or synthetic fibers, endless, chopped or carded for processing in weaving factories

  and production of knitted fabrics and knitwear.

  Area of application Twisted sewing thread

  Made for ladies and girls in mesh and woven fabric.

  Clothing for men and boys, uniforms.

  Linen for men, women and children, shirts, T-shirts, blouses,

  bed sheets, pillowcases, corsets and knits.

  Making work clothes, sports clothes, jerseys

  of bath, etc ... of tents and articles of camping, sails, flags.

  For all clothing factories, including socks and

the socks.

  For leather garments, suitcases, bags, gloves,

  belts, suspenders and military items.

  1 41 Fur coats and, in general, articles

pelts.

  Shoes for women, men and children, shoes for

  skiing, sports and hiking, for slippers.

  For making curtains, double curtains, decoration, bed, table and household linen, tea towels and towels,

carpet.

  For the manufacture of hats, caps, ties, umbrellas. For the production of furniture upholstered in fabric, natural and synthetic leather, mattresses and bedding, quilts and cushions,

  for the production of seats for cars, trains and planes.

  For tarpaulins For trucks and railway cars, hoods for cars and boats, inflated halls, technical fabric (filter), bags and containers of fabric and plastic, for support belts, lifting belts and security, for blinds and

  awnings, for zippers.

249 431 1

Claims (20)

  1. Twisted yarn comprising at least one connection wire of a synthetic material which can be extruded by a die, characterized in that the connection wire has a melting point below 1550C and an elongation at break greater than 25%, and in that it achieves, at least under pressure, a connection   adhesive with the various components of the plied.   2. Twisted yarn comprising at least one connecting thread made of a material   synthetic, characterized in that the connecting thread is of the separating thread type   ration in copolyamide or copolyester.   3. Twisted yarn according to claim 1, characterized in that the melting point is between 70 and 1550C and in that preferably, the elongation at break is between 30 and 50%, for example between and 40%.   4. Twisted yarn according to claim 1, characterized in that the   connecting wire is made of a thermoplastic material.   5. Twisted yarn according to claim 1 or 2, characterized in that the connecting thread is made of a copolyamide, in particular a copolyamide   formed from at least three monomer components forming polyamides.   6. Twisted yarn according to claim 1 or 2, characterized in that   that the connecting thread is made of a copolyamide comprising at least three   statistically distributed saturated and unbranched monomer posers forming   polyamides, in that the average proportion of amides comprises 1 CONH-   for 6.4 to 7.4 -CH2- (or 1 -CH2- for 0.156 to 0.135 -CONH-), and in that each monomer component represents from 10 to 60 mol% of the totality of all the monomer components, the sum of the molar percentages of all the monomer components being equal to 100, however the wires have points less than 1550C.   7. Twisted thread for sewing in the composition of which between natural threads according to claim 1 or 2, characterized in that the thread   of bond at a melting point between 70 and 900C.   8. Twisted sewing thread containing polyamides as claimed   cation 1 or 2, characterized in that the connecting wire has a melting point between 105 and 140'C.   9. Twisted sewing thread containing polyesters as claimed   cation 1 or 2, characterized in that the connecting wire at a melting point between 140 and 1550C.   10. Twisted yarn according to claim 1 or 2, characterized in   that the bonding wire represents 0.5 to 15% of the totality of the final wire.   11. Method for producing a plied yarn according to at least one of 249431 î   previous claims, characterized in that the twist is subjected to a   heat treatment between 70 and 200 ° C, preferably between 70 and 1550C.   12. Method according to at least one of the preceding claims,   characterized in that the heat treatment is carried out, preferably with at least one intermediate evacuation, for at least 30 minutes, for example   between 50 and 140 minutes, especially in an autoclave.   13. Method according to at least one of the preceding claims,   characterized in that the heat treatment is carried out on a plied twisted yarn, in particular on a plied yarn stretched to the limit of its resistance tensile.   14. Method according to at least one of the preceding claims,   characterized in that the twist is treated with steam.   15. Method according to at least one of the preceding claims,   characterized in that at least two, preferably three, initial twists are twisted together, and that the resulting twisted yarn is subjected under tension to a rewinding under tension, for example under a tension of 600 to 1100 grams,   for the following heat treatment.   16. Method according to at least one of the preceding claims,   characterized in that the ply is treated for 80 to 140 minutes at a temperature   rature from 110 to 2000C, in particular between 110 and 1400C, preferably by steam.   17. Method according to at least one of the preceding claims,   characterized in that one or more intermediate evacuations are carried out during treatment.   18. Method according to at least one of the preceding claims,   characterized in that during the rewinding of the plied yarn preceding the treats   thermally, the connecting wire is stretched under a tension which is approximately   10 times higher than the drawing tension of the support wires.   19. Twisted process and yarn as described in all combinations possible sounds.   20. Application of plied yarns according to at least one of the claims   1 to 19, in the weaving industry, in the production of knitted fabrics and in hosiery.