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
  • D02G1/00—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics
  • D02G1/12—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics using stuffer boxes
  • D02G1/127—Producing crimped or curled fibres, filaments, yarns, or threads, giving them latent characteristics using stuffer boxes including drawing or stretching on the same machine

Definitions

• the present invention relates to a process for the fixation of pressure crimped synthetic fibers, especially polycaprolactam fibers, more particularly to a process of fixation carried out in the crimping device.
• a pair of take-in rollers is provided for feeding into a chamber a rope to be crimped; said chamber is filled with the fiber rope and the fibers are constantly held under crimping pressure.
• This chamber is, however, not filled completely; there is a small free space below the point of contact of the rollers, which has an approximately triangular cross-section and is formed by the rollers and the upper surface of the chamber contents.
• the height of the triangle and the length of the base line formed by the chamber contents depends on the pressure prevailing in the chamber.
• the fiber As the fiber is fed in by the rollers, it strikes the base of the triangle, bends back and tends, by continued folding, to fill the empty space, narrow-angled arcs alternating with straight parts, so that a wave-like form of the fiber is obtained.
• the shape of completely synthetic fibers can be fixed by treatment with dry heat or moist steam in special devices at certain pressures, and at temperatures of about 120 to 130 C.
• the present invention is based on the discovery that the temperature in the chamber can be so raised by the folding of the fibrils and the heat generated in their bending that the polycaprolactam fibers become moldable and may even be melted. This can be done by making the take-in speed in the crimping device about twice as high as prac- 2,888,733 Patented June .2, 195.9
• each folding takes about 0.0002 second, the number of folds formed per minute is several billions with the conventional rope sizes.
• the material is heated to such an extent, that the water contained therein evaporates, so that a better heat distribution is obtained.
• the temperatures are of the magnitude of the usual temperatures of fixation, namely C. to C.
• the crimped and fixed material is tested for crimping fastness as follows: The ends of a single polycaprolactam fiber are secured, under a low pretension of 10 mgs. and a free length of 20 mm., in the clamps of a single-fiber test apparatus with pendulum balance or torsion balance. The crimped fiber is then stretched until it is completely de-crimped or straight. The de-crimping tension should not be of such magnitude as to effect a stress on the cross-section of the fiber.
• a polycaprolactam fiber iss ubjected to 10 stretchings for 1 minute each, with 2 minutes for recovery between stretchings.
• the clamp distance during the recovery periods is the original 20 mm.
• the fiber is stretched wthin the clamp with another 10 mgs. or at the highest 2 mgs.
• the crimping fastness of the polycaprolactam fiber may be computed in percent according to the formula:
• Example 1 A rope of about 100,000 den. with about 28,000 single fibrils of 3.75 den. and a moisture content of about 5% are crimped at a feeding speed of about 80 m./min. According to the measuring method described above, the crimping fastness has been determined at about 30%.
• the same rope with a moisture content of 10% and a feeding speed of about m./min. shows, after crimping, a crimping fastness of about 55%.
• Example 2 A rope as specified in Example 1 with a moisture content of 5% and 80 m./min. feeding speed, is subjected to a fixing process in boiling water for some time and yields a crimping fastness of about 53%.
• the same rope When the same rope is fed into the crimping device with a moisture content of about 10% at a feeding speed of m./min., and is fixed in the crimping device proper, it exhibits a crimping fastness of about 56%, which is n 3., practically identical with the one above. No separate operation has, however, to be performed to obtain this crimping fastness.
• the rope which is fed into the crimping chamber may contain some added wetting agent.
• a process for the fixation of pressure orimped synthetic polycaprolactam fibers by heat-setting in a crimping chamber without injection of setting agents into said chamber, which comprises feeding a rope of polycapro laetarn fibers having a moisture content of 5 to 10 percent into a crimping chamber at a speed of 100 to 250 meters per minute, generating a hot, moist, setting atmosphere by virtue of the folding of the fibers, the

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Ropes Or Cables (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4533510

Family Applications (1)

Country Status (4)

Cited By (4)

Citations (4)

• 1953
  • 1953-06-27 CH CH326113D patent/CH326113A/de unknown
• 1954
  • 1954-05-28 GB GB15879/54A patent/GB746216A/en not_active Expired
  • 1954-06-10 DE DEI8766A patent/DE1061952B/de active Pending
  • 1954-06-18 US US437863A patent/US2888733A/en not_active Expired - Lifetime

Patent Citations (4)

Also Published As

Similar Documents