Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/22—Formation of filaments, threads, or the like with a crimped or curled structure; with a special structure to simulate wool
  • D01D5/23—Formation of filaments, threads, or the like with a crimped or curled structure; with a special structure to simulate wool by asymmetrical cooling of filaments, threads, or the like, leaving the spinnerettes
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
  • D01D5/00—Formation of filaments, threads, or the like
  • D01D5/22—Formation of filaments, threads, or the like with a crimped or curled structure; with a special structure to simulate wool
• • 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
  • D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D01F6/04—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyolefins
  • D01F6/06—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyolefins from polypropylene

Definitions

• Fibres or filaments spun from isotactic propylene polymers may be utilised in several ways. They may be drawn and used as continuous filament yarns or they may be drawn .and cut into short lengths and further processed as staple fibre in which form they may be processed on conventional textile machinery either alone or mixed with other natural or synthetic fibres. Staple fibres may be utilised for producing filling materials of high bulk. It is an essential part of the staple fibre process that a wavy form should be imparted to the fibres to assist their processing on conventional textile machinery, especially when mixed with natural fibres having this wavy or crimped form. The crimping of the fibres also imparts softness and bulk to yarns produced from them, leading to greater warmth in fabrics produced from such yarns.
• Filaments spun from i-sotactic polypropylene may be utilised also as textured or bulked filament yarns which are produced by, for example, a false-twisting process after the drawing stage of the filament yarn prowss.
• I provide a process for the production of fibres or filaments of isotactic polypropylene as hereinbefore defined having a helically crimped form characterised in that the crimped form is spontaneously developed by spinning the filaments of isotactic polypropylene at such a temperature and at such a throughput from polymer of an intrinsic viscosity such that the intrinsic viscosity of the spun yarn is in the range 1.0 to 3.0 preferably 1.5 to 2.5 and the birefringence of the spun yarn is between 10 10- and 25 19- and then drawing the spun yarn to 1.2 to 4.0 times its original length the stretched yarn thereafter being allowed to relax freely and quickly.
• Birefringence which indicates the degree of orientation of the spun filaments, may be measured by means of a 3,233,023 Patented Feb. 1, 1966 polarising microscope fitted with a suitable compensator.
• the intrinsic viscosity which is conveniently measured in solution in decalin at 135 C., has the meaning defined in the standard reference textbooks, for example on page 309 of the 1953 edition of Principles of Polymer Chemistry by P. J. Flory.
• I spin isotactic polypropylene having an intrinsic viscosity between about 1.5 and 2.5 at a temperature between 200 and 300 C. and a wind-up speed between 1,000 and 5,000 feet per minute so that the spun filaments have a birefringence between 15 X10- and 20X 19- and an I.V. between 1.2 and 2.5.
• These filaments are then cold drawn using a draw ratio between 1.2 and 4.0 and upon relaxation f the drawn yarn spontaneous crimping of the filaments took place. Degrees of crimping between about 5 and 50 turns/inch have been attained by this technique.
• the degree of crimping may be expressed either as the number of turns per inch or as the percentage crimp which is expressed by the relation where L is the length of the filament with the crimps present 1. is the length of the same filament when extended just sufficiently to remove the crimps.
• the temperature of the heated pin, roller or other device whereon drawing takes places may be varied over a wide range of temperature from about 10 C. to about 140 C. and a spontaneous crimping effect is still obtained on release of the drawing tension.
• a suitable apparatus comprises a screw extruder, from which molten poly propylene is supplied to a spinneret via a metering pump. Filtration of molten polymer is desirable both before and after it passes through the metering pump, the temperature of the first filter can, if desired, be well below that of stage drawing was omitted, the winding tension of the spun yarn'was released and the yarn allowed to relax freely at 140 C. to develop the full helical crimping effect.
• polypropylene The following table shows the percentage crimp deof high intrinsic viscosity, for example, 3.0 to 4.0, may veloped in yarns spun under various conditions. be used as starting material and thermally degraded in the melter to give the desired level of intrinsic viscosity in the spun yarn.
• Crimped fibres or filaments produced according to the g process of my invention are very suitable for use in textile applications, especially for preparing carpets, blankets, apparel fabrics or other textile products where the crimped structure leads to such desirable properties as What I claim is: resilience, cohesiveness or bulk of the staple or continuous 25 1.
• a process for the production of crimped filaments filament yarns comprising such crimped fibres, either of isotactic polypropylene comprising producing isotacalone or mixed with natural fibres or other synthetic fibres.
• tic polypropylene filaments having an intrinsic viscosity Because of their enhanced bulk and resilience fibers proof between about 1.5 and 2.5 and a birefringence of beduced by the process of present invention are particularly tween about 10 10 to l9 10- said producing step suitable for use as filling material in, for example, pilincluding the steps of melt spinning a polypropylene of lows and cushions.
• intrinsic viscosity between 1.0 and 6.0 at a spinneret tem- The examples which follow illustrate but in no way perature between 175 C. and 320 C, to form filaments limit our invention.
• the spun filahas been added was fed into a screw melter from which ments have an intrinsic viscosity of 1.8 to 2.2
• the windthe molten polymer was supplied to a metering pump and up speed is 1000 to 3500 feet per minute
• the birefrinthence through a filter consisting of 1020 mesh sand to gence of the filaments is 15X 10 to 19x10 and the a two hole spinneret (hole diameter 0.015 inch).
• the draw ratio is 1.25 to 2.0
• screw melter, metering pump and filter were enclosed in 3.
• a process according to claim 2 wherein the intrinsic an electrically heated jacket which was maintained at the viscosity of the polypropylene being spun is about 3.2 required spinning temperature.
• the spun yarns were and wherein the drawing is carried out at about C. at then cold drawn using a water bath at 90 C. at the rea draw speed of about 200 feet per minute. quired draw ratio and at a draw speed of 200 feet per 4.
• the drawn yarns were then relaxed quickly by 50 laxed yarn is stabilized by heating to a temperature of cutting the yarn off the draw bobbin and stabilised by C. to 140 C. heating in air at 140 C. for twenty minutes. 5.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Artificial Filaments (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (1)

Publications (1)

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Family Applications (1)

Country Status (6)

Cited By (6)

Families Citing this family (3)

Citations (4)

• 0
  • NL NL289452D patent/NL289452A/xx unknown
  • BE BE628987D patent/BE628987A/xx unknown
• 1962
  • 1962-02-27 GB GB7636/62A patent/GB964406A/en not_active Expired
• 1963
  • 1963-02-21 US US260330A patent/US3233023A/en not_active Expired - Lifetime
  • 1963-02-27 DE DE19631435493 patent/DE1435493A1/de active Pending
  • 1963-02-27 AT AT154663A patent/AT241010B/de active
  • 1963-06-24 GB GB25032/63A patent/GB1018851A/en not_active Expired

Patent Citations (4)

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