Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/22—Yarns or threads characterised by constructional features, e.g. blending, filament/fibre
  • D02G3/36—Cored or coated yarns or threads
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/46—Sewing-cottons or the like
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/04—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyesters, e.g. polyethylene terephthalate [PET]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S57/00—Textiles: spinning, twisting, and twining
  • Y10S57/903—Sewing threads

Definitions

• the present invention relates to new core yarns containing a selected core material, adapted processes for their production, and the use of selected polyester materials for the production of core yarns.
• Core yarns are known per se and are used in particular as sewing threads. Such yarns usually consist of one or more core threads, each of which consists of a core thread made of synthetic material, which is covered in a spinning process with fibers of vegetable, semi-synthetic or fully synthetic origin or mixtures thereof with simultaneous twisting so that the core thread is practically completely covered .
• Core yarns of this type are known, for example, from DE-AS-1,550,040, DE-Gbm-75-37,019, DE-A-2,436,997 and EP-A-241,857.
• the core threads are made of high-strength synthetic material, while the sheathing usually does not make any significant contribution to the strength of the yarn.
• the covering primarily serves to protect the core material against overheating under high mechanical stress, for example when used in industrial sewing machines.
• High-strength polyester filaments for this use are known from DE-A-2,436,997 and EP-A-241,857.
• EP-A-173,200 provides multifilament supply threads for the production of Sewing threads are known, which consist of fast-spun, highly drawn and high-molecular polyester material.
• the production of core yarns from this material is not explicitly mentioned.
• the supply threads known from this publication can be processed into sewing threads which have a high sewing length under difficult conditions and have a high seam strength.
• the present invention provides a sewing thread with the desired property profile.
• the term “covered with fibers ... so that the soul thread is practically completely covered” is to be understood in the context of this invention as such a covering of the soul thread by the winding fibers that the soul thread is subject to practically no change in its mechanical properties under sewing conditions, and that in particular the strengths and the loop strengths of the soul material before and after sewing are essentially unchanged, that is, for example only decrease by a maximum of 10%.
• the tenacity (measured according to DIN 53 834) of the core yarns according to the invention is usually more than 40 cN / tex, preferably 42 to 46 cN / tex. This is the maximum tensile force, based on the titer of the entire core yarn.
• the loop strength (measured according to DIN 53 843) of the core yarns according to the invention is usually more than 29 cN / tex, preferably 30 to 34 cN / tex.
• the reference elongation at 300 cN load (measured according to DIN 53 834) of the core yarns according to the invention is usually less than 3.5%, preferably 2.8 to 3.2%.
• the maximum tensile force elongation (measured according to DIN 53 834) of the core yarns according to the invention is usually less than 20%, preferably 16 to 19%.
• the maximum tensile elongation is the stretch that the yarn experiences when the maximum tensile force is applied.
• the thermal shrinkage at 180 ° C. (measured according to DIN 53 866, part 3) of the core yarns according to the invention is usually less than 2%, preferably 1.4 to 1.8%.
• a sewing test with the help of an industrial sewing machine under standardized conditions serves as a measurement.
• the suitability of a sewing thread can be concluded from the length of the seam produced.
• An industrial sewing machine from Pfaff with a Nm 90 needle is used; Sewing is done by setting a lockstitch with four stitches per centimeter and a sewing speed of 5000 stitches per minute.
• the thread is loaded at 220 cN.
• a fourfold layer of cotton twill is sewn with a basis weight of 350 g / m2 each, which has 33 warp and 20.5 weft threads per centimeter.
• a standard fabric for work suits was used.
• the measured value "sewing length" indicates the length of the seam in centimeters until the thread breaks and is an average of ten sewing attempts per test spool.
• the core yarns according to the invention show "sewing lengths" of more than 800 cm, preferably 875 to 1050 cm, when sewing forward.
• Seam strength is another parameter for assessing the properties of sewing threads. It is determined by the use of an industrial sewing machine, e.g. from Pfaff, with the machine setting specified above. Upper and lower threads are the same in this test and each consist of the core yarn according to the invention. The thread load is optimally adjusted for a good seam appearance, a double layer of cotton twill is sewn. The same material is used as the cotton twill that was used for the sewing length determination.
• the seam strength is the maximum tensile strength of a 5 cm wide strip. The tensile force is determined in a tensile tester at a working speed of 10 cm per minute.
• Core yarns are preferred which have a final titer of 100 to 1500 dtex, in particular of 130 to 750 dtex.
• the core thread of the core yarns according to the invention preferably has a titer of 45 to 300 dtex. If there are several core threads in the core yarn, this titer multiplies according to the number of core threads.
• the core yarn according to the invention preferably consists of two twisted soul threads, each of which in turn is coated with fibers of vegetable, semi-synthetic or fully synthetic origin, so that the soul thread is practically completely covered.
• the weight ratio of core filaments to wrapping fibers of the core yarn according to the invention is usually 30:70 to 50:50, preferably about 40:60.
• Soul and wrapping fibers generally differ in terms of their individual titer. This is usually 2 to 10 dtex for the soul filaments.
• For the wrapping fiber is usually 1 to 2 dtex in the case of polyester fibers.
• the core material of the core yarn according to the invention consists of polyester of the specifications given above.
• the core material is used in the form of multifilament yarns.
• the core yarn of the core yarns according to the invention can in principle consist of any fibers.
• the term "fiber” is to be understood in its broadest meaning, ie as multifilament or as staple fiber.
• the thread is also not subject to any restrictions in terms of material. Fibers of plant, semi-synthetic or fully synthetic origin can be used in the broadest sense, provided they are suitable for protecting the soul thread during sewing.
• Examples of fibers of plant origin are cotton fibers.
• fibers of semi-synthetic origin are cellulose fibers, e.g. are obtainable by the xanthate process.
• fibers of synthetic origin are fibers made of synthetic spinnable polymers and polycondensation products, such as e.g. from polyamides, polyacrylonitrile and in particular from polyesters.
• Suitable polyesters for the core material and, if appropriate, the wrapping yarn are those which essentially consist of aromatic dicarboxylic acids, such as 1,4-, 1,5- or 2,6-naphthalenedicarboxylic acid, isophthalic acid or in particular terephthalic acid and aliphatic diols with 2 to 6, in particular 2 to 4 carbon atoms, such as ethylene glycol, 1,3-propanediol or 1,4-butanediol, can be obtained by cocondensation. Hydroxycarboxylic acids are also suitable as starting materials for polyesters.
• polyester raw materials can also be obtained by condensing in small amounts of aliphatic dicarboxylic acids, e.g. Glutaric acid, adipic acid or sebacic acid or of polyglycols such as e.g. Diethylene glycol, (2,2'-dihydroxydiethyl ether), triethylene glycol, (1,2-di- (2-hydroxy-ethoxy) ethane) or also of smaller proportions of higher molecular weight polyethylene glycols can be modified.
• aliphatic dicarboxylic acids e.g. Glutaric acid, adipic acid or sebacic acid
• polyglycols such as e.g. Diethylene glycol, (2,2'-dihydroxydiethyl ether), triethylene glycol, (1,2-di- (2-hydroxy-ethoxy) ethane) or also of smaller proportions of higher molecular weight polyethylene glycols can be modified.
• a further modification possibility which in particular influences the dyeing behavior of the core yarns according to the invention, is the modification by building blocks containing sulfo groups, such as e.g. through the incorporation of sulfoisophthalic acid.
• the upper limit of the final strength of the core yarns according to the invention depends, among other things, on the degree of condensation chosen for the polyester material used in the core material.
• the degree of condensation of the polymer is expressed in its viscosity. A high degree of condensation, i.e. a high viscosity leads to particularly high final strengths.
• polyesters used as core materials according to the invention have a relative solution viscosity (determined on solutions of 1 g of polyester in 100 ml of dichloroacetic acid at 25 ° C.) of at least 1.9.
• polyesters which have a relative solution viscosity of 1.9 to 2.4, in particular of 1.95 to 2.1.
• a preferred polyester material for the production of the core and, if appropriate, the wrapping yarn of the core yarns according to the invention is polyethylene terephthalate or copolyester containing recurring ethylene terephthalate units.
• the core threads of the core yarns according to the invention have a maximum tensile force of at least 60 cN / tex, preferably 65 to 90 cN / tex.
• polyester core and cotton wrap yarn is particularly preferred.
• a fast-spun polyester multifilament is used as the core material, which has subsequently been drawn up to achieve optimum strength.
• the use of such high-strength and rapidly spun yarns for the production of core yarns has not been described to date and, like the production of these yarns, is an object of the present invention.
• the fast-spun polyester multifilament intended as core material has a high orientation, which is noticeable in a high birefringence.
• Typical values for birefringence are in the range from 15 x 10 ⁇ 3 to 40 x 10 ⁇ 3.
• the multifilament After rapid spinning, the multifilament is stretched high to achieve optimal strength. It is known to the person skilled in the field of fiber production that, depending on the drawing temperature selected, there is a maximum of the achievable strength.
• the rapidly spun multifilaments are subjected to such stretching conditions as the stretching temperature and degree of stretching, so that the optimum strengths for the fast-spun multifilament yarn in question are achieved with a maximum tensile elongation of about 15%. This also includes strengths that are up to 30% below this optimal value.
• the winding of the core material with the winding yarn can be carried out in a manner known per se. Methods of making such casings are e.g. known from DE-A-2,436,997.
• a multifilament yarn made of polyethylene terephthalate is produced by melt spinning and drawn off at 2000 m / min.
• the polyethylene terephthalate used has a relative viscosity of 1,940.
• the fast spun multifilament yarn has a birefringence of 18 X 10 ⁇ 3, is then drawn in a ratio of 1: 2.97 at 75 ° C and then fixed.
• the fixing temperature is 230 ° C.
• a core yarn is made from this multifilament yarn by spinning with cotton. Two of these core yarns are twisted together and then dyed. The properties of the individual production stages are listed in Table 1.
• Example 1 Analogously to Example 1, a core yarn is produced from polyester multifilament yarn and cotton, twisted twice and dyed. In contrast to Example 1, no quickly spun polyester multifilament yarn is used as the core material used, but a commercially available high-strength polyester multifilament yarn. The properties of the individual production stages are also listed in Table 1.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Artificial Filaments (AREA)
• Multicomponent Fibers (AREA)

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Publications (2)

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Citations (5)

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• 1993
  • 1993-09-29 EP EP93115702A patent/EP0591827B1/fr not_active Expired - Lifetime
  • 1993-09-30 FI FI934302A patent/FI102909B1/fi active
  • 1993-09-30 BR BR9303991A patent/BR9303991A/pt not_active IP Right Cessation
  • 1993-10-01 MX MX9306127A patent/MX9306127A/es not_active IP Right Cessation
  • 1993-10-01 NO NO933523A patent/NO933523L/no unknown
  • 1993-10-01 CA CA002107515A patent/CA2107515A1/fr not_active Abandoned
  • 1993-10-04 JP JP5248003A patent/JPH06192929A/ja active Pending
• 1997
  • 1997-03-18 US US08/819,303 patent/US5735110A/en not_active Expired - Fee Related
• 1999
  • 1999-10-27 GR GR990402725T patent/GR3031636T3/el unknown

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