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
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/46—Sewing-cottons or the like
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
  • D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
  • D01F6/62—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyesters

Definitions

• the present invention relates to high-strength multifilament polyester supply threads for the production of sewing threads and a method for their manufacture.
• Sewing threads are to be understood in this patent as sewing threads.
• supply threads are required, which in the present case should consist of endless polyester threads.
• Sewing threads of this type must have high strength, be easy to sew, provide good seam strength and be low-shrinkage in order to prevent the seams from warping during washing or during thermal treatment.
• polyester yarns described in Japanese Patent Application Laid-Open No. 51-53019 could be based at least in part on the low molecular weight of these yarns.
• the use of thread-forming polyesters with a relatively low molecular weight is widespread in the production of high-strength yarns, since polyesters with a higher average molecular weight should have a lower modulus of elasticity and, in particular, high shrinkage values.
• This dependency is mentioned, for example, in the German interpretation 23 32 720, column 2, lines 41 to 46.
• the process according to the invention consists of high-speed spinning of high molecular weight polyester, whereby measures known per se, such as, for example, nozzle heating, are intended to minimize the molecular weight degradation during the spinning process.
• the fixing temperature of 225'C and below allows the production of the yarns according to the invention on conventional stretching devices.
• the draw ratio must of course be adapted to the higher pre-orientation of the supply yarns.
• the birefringence of the threads serves as a measure of the pre-orientation.
• the reference elongation (D 45 ), ie the elongation / which is measured at 45 cN / tex, is a measure of the elasticity of the threads.
• the reference elongation is also influenced by the possible presence of a "shrink saddle" in the force-elongation diagram (KD diagram).
• KD diagram shows a greater or lesser degree of elongation of the material in the case of thermo-mechanically shrunk threads after a usual steep increase even with relatively low tensile stresses.
• the hot air shrink S 200 or S 180 was determined according to DIN 53866 at temperatures of 200 or 180 ° C.
• the proximity properties were determined using a specially developed test method, for which patent protection is sought in the same day's application.
• a sewing test with the help of an industrial sewing machine under standardized conditions served as the measured variable.
• the suitability of a sewing thread can be concluded from the length of the seam produced.
• An industrial sewing machine from Pfaff was used with a Nm 90 needle, sewing was done with a double lockstitch with 5 stitches per centimeter and normally a sewing speed of 4000 stitches per minute.
• the thread tension of the upper thread is 175 to 180 cN, the lower thread consists of a good sewing thread made of cotton. The tension of the lower thread is adjusted so that the loops in the material disappear (perfect seam appearance).
• a 5-ply layer of cotton twill with a basis weight of 185 g / m 2 is sewn, which has 95 warp and 50 weft threads per centimeter.
• a standard fabric for work suits from Nadler & Sohn, Augsburg, item no. 13960-80 / 2, dark-colored construction was dyed and sanforized.
• the measured value "sewing length" indicates the length of the seam in centimeters until the thread breaks and is an average of 10 sewing attempts per test spool.
• the test process is interrupted if a sewing length greater than 1000 cm is found during a measurement, since experience has shown that sewing lengths over 1000 cm can in any case be described as very good sewing behavior.
• the requirements for the sewing test can be made more difficult.
• the above-mentioned conditions are met in the difficult sewing test, but with a thread tension the upper thread of 220 cN worked and with a stitch count of 5000 stitches / minute.
• Seam strength is another parameter for assessing the properties of sewing threads. It is determined by using an industrial sewing machine e.g. from the Pfaff company. Machine setting: lockstitch 5 stitches per centimeter seam length, 4000 stitches / minute. The upper and lower threads are the same in this test and consist of the sample. The thread tension is optimally adjusted for a good seam appearance, a double layer of cotton twill is sewn. The same material that was used for the sewing length determination was used as the cotton twill.
• the seam strength is the maximum tensile strength of a 5 cm wide strip. This pulling force is determined in a pulling device with a working speed of 10 cm per minute. The value found is converted to the individual thread.
• knife abrasion number is determined using a modified abrasion tester from Zweigle with the designation G 550 S, the rotating test specimen having a hard metal profile abrasion bar.
• G 550 S the rotating test specimen having a hard metal profile abrasion bar.
• 20 thread loops are placed on the device and each loaded with a weight such that the thread tension is 0.135 cN / dtex.
• the number of scrubbing tours is determined, which is necessary until one of the 20 test loops used is worn through.
• the threads were spun out by melting suitable polyethylene terephthalate materials in an extruder (whereby when using highly viscous polyester materials the spin pack temperature was kept at 290 * C, but the die temperature was kept at 315 * C. In contrast, spinning with a lower viscosity was carried out with a spin pack and Nozzle temperature of 295 ° C. In each case, nozzles with 32 holes were used After the threads had cooled in the spinning shaft, the threads were wound up at 800 or 1000 or, according to the invention, at 3000 m per minute, for example.
• the spinning bobbins obtained were then presented to so-called three-pallet machines, for example an SZ 26 from Barmag.
• the threads are drawn off from the spinning bobbin and heated to the drawing temperature of usually 87 ° C. on a first godet, which is looped 6 times, for example, and then passed on to a second heated godet, which is heated to the fixing temperature.
• the stretching takes place between the first and second godets.
• the draw ratio used depends on the pre-orientation of the filaments. It is detailed in the table below.
• the thread is passed onto a third godet, which is usually not heated.
• the thread material can be relaxed between the second and third godets.
• the stretched threads are then wound onto cops.
• the thread material received only a protective twist of about 10 turns per meter under these conditions.
• the thread material thus obtained represents the supply threads for the production of a sewing thread.
• the supply threads must be rewound on supply spools. They are then submitted to a LEZZENI twine-type twister type TBR to test their properties.
• This machine operated at a speed of 10 m / min and produced a triple thread of 138 dtex f 32 S 840 x 3 Z 540.
• the threads obtained were subjected to HT dyeing at 135 ° C. for 120 minutes.
• the dyed thread was then examined for its textile properties and in particular its suitability as a sewing thread.
• the measured values obtained are shown in the table below.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Artificial Filaments (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
• Polyesters Or Polycarbonates (AREA)

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Applications Claiming Priority (2)

Publications (4)

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Family Applications (1)

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Cited By (4)

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Citations (4)

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• 1984
  • 1984-08-30 DE DE19843431834 patent/DE3431834A1/de not_active Withdrawn
• 1985
  • 1985-08-19 DE DE8585110343T patent/DE3563226D1/de not_active Expired
  • 1985-08-19 EP EP85110343A patent/EP0173200B2/fr not_active Expired - Lifetime
  • 1985-08-19 AT AT85110343T patent/ATE35003T1/de not_active IP Right Cessation
  • 1985-08-29 CA CA000489635A patent/CA1300361C/fr not_active Expired - Fee Related
  • 1985-08-29 BR BR8504164A patent/BR8504164A/pt not_active IP Right Cessation
  • 1985-08-29 JP JP60188730A patent/JPS6163713A/ja active Pending

Patent Citations (4)

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