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
  • D01D5/06—Wet spinning methods
• • 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
  • D01F2/00—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof
  • D01F2/24—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from cellulose derivatives
  • D01F2/28—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from cellulose derivatives from organic cellulose esters or ethers, e.g. cellulose acetate

Definitions

• This invention relates to the wet spinning of cellulose triacetate to form filamentary materials.
• Textile materials of cellulose triacetate have recently attained considerable commercial importance. On suitable after-treatment, these textile materials have superior heat resistance,- high safe-ironing temperatures, excellent wash-fastness even when dyed in heavy shades, crease resistance and resistance to glazing and to shrinkage on pressing with moist steam.
• cellulose triacetate filamentary materials of greater strength and high elongation can be prepared by wet spinning of the cellulose triacetate, i.e. by extrusion of a solution of the cellulose triacetate into a-coagulating or spin bath which exerts a swelling action on the filamentary material.
• a solution of the cellulose triacetate into a-coagulating or spin bath which exerts a swelling action on the filamentary material.
• the filaments tend to coalesce to an appreciable extent, i.e. they bond laterally to one another.
• a solution of cellulose'triacetate. in a solvent comprising methylene chloride is extruded through 'a spinnerette, preferably provided with a plurality of orifices, into a spin bath containing methylene chloride and preferably a lower aliphatic alcohol such as methanol.
• methylene chloride preferably a lower aliphatic alcohol
• the resulting swollen cellulose triacetate filaments are then treated with a liquid organic non-solvent for cellulose triacetate. It is found that upon drying the filaments are uncoalesced.
• the use of certain critical proportions of methylene chloride in the spin bath results in the production of filamentary materials of outstanding physical properties (e.g. tenacity of at least 1.8 grams per denier and elongation of at least 18%).
• proportions of methylene chloride within the scope of the Riley application.
• the stretching force is most conveniently applied by means of a positively driven feed roll, such as a godet roll, over which the filaments pass, as a bundle, after they leave the spinbath.
• the liquid organic non-solvent for cellulose triacetate which can be employed to treat the bundle of cellulose triacetate filaments from the spin bath is preferably miscible with methylene chloride and boils below C.
• Representative substances include hydrocarbons such as aliphatic compounds and mixtures thereof, cycloaliphatic compounds such as cyclohexane, aromatic compounds such as benzene and its lower alkyl substitution products such as toluene and xylene, others such as isopropyl ether, and the like.
• xylene is particularly satisfactory since it permits a marked reduction in coalescence in a short time of contact, and the filaments have desirable physical properties such as high strength and satisfactory elongation.
• the bundle of filaments can be immersed freely in the treating bath after leaving the spin-bath without being taken up on a bobbin.
• the bundle of filaments leaving the spinbath is passed about a positively driven feed roller, through a second bath containing the treating liquid and is taken up on a bobbin. the second bath to maintain the yarn submerged therein. It is generally advantageous to maintain a low tension on the yarn during the treatment of this invention, so as to produce a final product of desirable high elongation with a low degree of coalescence.
• the take-up bobbin may be run at a somewhat lower linear 1 velocity than the feed roller.
• the percent coalescence can be reduced by me chanically assisting the treatment, as by the use of suitable wiping devices in the treating bath, e.g. an aluminum magnesium silicate device having a satin-finished rounded wiping edge which will flatten the filament bun- It can conveniently be elfected on the bobbin or it can be I elfected with the filaments relaxed, i.e. filamentary material merely passes about a roller and is collected in a can where it is free to contract. a r
• the cellulose triacetate employed in accordance with this invention has an acetyl value of at least about 60%, preferably above 61%, calculated as acetic acid. Its concentnation in the spinning solution can range between about 18 to 26% by weight.
• the spinning solution solvent can contain up to about 15% by weight of methanol while the methanol content of the spin-bath is about 50%by weight.
• the percent coalescence as employed in the examples is that percentage ofthe total'nuniber of' filaments in a yarn bundle which participate in coalescence. t is found as follows: A piece of piano wire of 0.097 mm. diameter is looped through a hole of 1.02 diameter in a metal plate 0.62 mm. thick. A 10 cm. length of uncolored yarn to be examined is bundled with a blue yarn and the bundle is inserted through the loop of the wire. The wire loop is pulled through the hole in the plate, thereby doubling the filament bundle and draw.-
• the blue yarn serves to fill the hole and ensures a snug fit.
• the yarn is cut flush with the surfaces of the plate using a razor blade, thereby forming a thin section-
• a drop of decane is placed on c section to improve filament boundary definition, a cover glass is placed over the section and it is examined under a microscope at a magnification of 440.
• the number of filaments which are fused or bonded together is determined and the test repeated 8 times for each yarn.
• the percent coalescence is 100 times the average number of filaments of a section involved in coalescence vided by the total number of uncolored filaments in the section.
• the yarn After. emerging from the bath, the yarn is passed over a ball-bearing pulley and 3 meters downward to a driven feed roll and idler operating at a surface speed of 60 meters/minute. From the feed roll, the yarn passes through a 1.7 meter horizontal bath of xylene at room temperature to a take-up bobbin rotated at a peripheral. speed of 57-60 meters/minute. The yarn is dried on the bobbin by standing in air for 17 hours, then standing for 17 hours at 50 C. and an absolute pressure of 200 mm. of mercury, and finally standing for 20 hours at 50 C. and an absolute pressure-of 5 mm. of mercury. The percent coalescence of the yarn is 5.0%.
• EXAMPLE II Solutions of cellulose triacetate as described in Example I are spun vertically upwardly through a 1.0 meter height of spinning hath made up of a mixture of methylene chloride and methanol. The filaments pass about a godet and idler assembly, through a horizontal treating bath 95 cm. long, and then to a take-up roll, fixed guides being employed to submerge the yarn in the bath.
• the results using a variety of conditions and solvents are given in the following table:
• Process for the production of filamentary cellulose triacetate which comprises extruding a solution. of cellulose triacetate in a solvent therefor comprising methylene chloride into a spin bath comprising about 25 to of methylene chloride and a lower aliphatic alcohol to form filamentary cellulose triacetate, and. treating said filamentary cellulose triacetate with a liquid organic nonsolvent for cellulose triacetate which is miscible with methylene chloride and boils below about C.
• the spinbath comprises a mixture of. methylene chloride and methanol containing at least about 50% by weight of methanol.
• liquid organic non-solvent for cellulose triacetate comprises isopropyl ether.
• liquid organic non-solvent for cellulose triacetate comprises a cyclic hydrocarbon.
• liquid organic-non-solvent for cellulose triacetate comprises cyclohexane
• liquid organic non-solvent for cellulose triacetate comprises a monocyclic aromatic hydrocarbon.
• liquid organic non-solvent for cellulose triacetate comprises xylene.
• liquid organic non-solvent for cellulose tn'acetate comprises benzene.
• treating is efiected by continuously introducing said filamentary cellulose triacetate into a treating bath and removing it from said treating bath at a lower linear velocity than it is introduced, treating thereby being effected with said filamentary cellulose tn'acetate under low tension.

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)

Priority Applications (5)

Applications Claiming Priority (1)

Publications (1)

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Country Status (4)

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Citations (7)

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• 1957
  • 1957-10-21 US US691180A patent/US2999004A/en not_active Expired - Lifetime
• 1958
  • 1958-01-20 GB GB1854/58A patent/GB826098A/en not_active Expired
  • 1958-02-05 FR FR1200188A patent/FR1200188A/fr not_active Expired
  • 1958-02-05 DE DEC16243A patent/DE1276289B/de active Pending
• 1959
  • 1959-05-13 GB GB16378/59A patent/GB915623A/en not_active Expired

Patent Citations (7)

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