Classifications

• • 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
  • D01F2/06—Monocomponent artificial filaments or the like of cellulose or cellulose derivatives; Manufacture thereof from viscose
  • D01F2/08—Composition of the spinning solution or the bath
  • D01F2/10—Addition to the spinning solution or spinning bath of substances which exert their effect equally well in either
• • 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
  • D01F11/00—Chemical after-treatment of artificial filaments or the like during manufacture
  • D01F11/02—Chemical after-treatment of artificial filaments or the like during manufacture of cellulose, cellulose derivatives, or proteins

Definitions

• United States patent specification No. 2,986,446 describes a process for the manufacture of crimped viscose rayon fibres by extruding a viscose containing polyethylene glycol into an acid coagulating and regenerating bath containing zinc sulphate, stretching the filaments so formed and relaxing the stretched filaments in an aqueous medium.
• the important properties of crimp and extensibility of the filament can be controlled by a change in one or more of the inherent features of the process, but, in general, a change which causes an increase in one property has the effect of decreasing the other.
• the degree of crimp increases and the extensibility decreases when the filament is stretched more, whilst an increase in the zinc sulphate concentration in the bath increases the extensibility of the filament but decreases the degree of crimp.
• the properties of the filament can, therefore, be varied between high degree of crimp and low extension on the one hand and high extension and low degree of crimp on the other.
• the process is, however, incapable of producing a filament which combines the features of high degree of crimp and high extension.
• Crimped staple fibres may be used as the pile of carpets.
• the fibres should be extensible, as this contributes to their resistance to abrasion, and resilient, to preserve the appearance of the carpet during wear.
• Viscose rayon fibres can be made more resilient by cross-linking the constituent cellulose, but this modification causes a decrease in extensibility.
• a viscose rayon fibre suitable for cross-linking and use in carpet piles, should, therefore, be highly extensible so as to be able to tolerate the inevitable fall in extensibility which accompanies crosslinking and still retain sufiicient extensibility to maintain the resistance to abrasion.
• a process for the production of crimped viscose rayon fibres comprises extruding a viscose containing from 5 percent to percent of cellulose, from 5 percent to 10 percent of caustic soda, more than 0.05 percent of a modifier and a zinc compound in the proportion of from 0.01 percent to 0.8 percent of zinc based on the weight of the viscose, at a salt figure of between 3 and 14, into a coagulating and regenerating bath containing from 5 percent to 14 percent of sulphuric acid, from 0.5 percent to 4 percent of zinc sulphate and more than 12 percent of sodium sulphate, to form incompletely regenerated filaments, stretching the filaments by at least 50 percent, cutting the stretched filaments into staple fibres and crimping the fibres by relaxing the fibres in a solution containing between 1 percent and 5 percent of caustic soda, before completing the regeneration of the cellulose in the fibres.
• the increase in the extensibility of the fibre is due, in the main, to two additions to the acknowledged, known process.
• the first of these is the use of a zinc compound, preferably an alkali metal zincate, in the viscose.
• a zinc compound preferably an alkali metal zincate
• This allows a desired degree of crimp to be obtained from a lower stretch, thus preserving to a greater extent the extensibility of the fibre.
• the effect is noticeable even 3,340,340 Patented Sept. 5, 1967 when the zinc sulphate concentration in the bath is high, that is at or near 4 percent and, thus, the zinc in the viscose can be used to reduce the antagonistic action of zinc in the bath to the crimp in the fibre.
• the second addition is that of relaxing the incompletely regenerated fibre in a dilute caustic soda solution. This has a remarkable elfect on the extensibility, causing increases of as much as 50 percent of the preexisting extensibility without deleteriously affecting the degree of crimp.
• the relaxation of dried cellulose fibres in caustic soda solutions is a process which can only achieve increases of the order of 10 percent in the extensibility of the fibres, and the process is less efiicient than that of similarly treating the incompletely regenerated fibre.
• the regeneration of the cellulose is more economically accomplished by continuing to treat the fibre with caustic soda, which hydrolyses the xanthate groups, rather than by reverting to an acid environment, in which the regeneration is due to the decay of free xanthic acid groups.
• caustic soda which hydrolyses the xanthate groups
• the change over from alkaline to acid conditions obviously involves the consumption of both acid and alkali.
• the principle of alkaline regeneration is applicable in the manufacture of all kinds of viscose rayon fibres, but, in general, is useful only where an essential alkaline treatment follows the acid coagulation step.
• the invention consists in extruding a viscose containing from 7.5 percent to 8.3 percent of cellulose, caustic soda such that the ratio of caustic soda to cellulose is between 0.7 and 0.9, 0.1 percent to 0.3 percent of polyethylene glycol having an average molecular weight of between 600 and 6,000 and a zinc compound in a proportion of from 0.04 percent to 0.2 percent of zinc based on the weight of the viscose, at a salt figure of from 5.5 to 8.5, into a coagulating and'regenerating bath containing sulphuric acid in a concentration of from 1.0 to 1.4 times the caustic soda content of the viscose, from 1 to 2 percent of zinc sulphate and between 22 and 24 percent of sodium sulphate, to form incompletely regenerated filaments, stretching the filaments by at least 60 percent of their original length in air, cutting the filaments into staple fibres and crimping the fibres by suspending the fibres in a solution containing between 1.5 and 2.5
• Example 1 A viscose containing 8.3 percent of cellulose, 6.2 percent of caustic soda, 0.166 percent of polyethylene glycol having an average molecular weight of 1,500, and 0.22 percent of sodium zincate was extruded at a salt figure of 6 into a regenerating bath containing 7.8 percent of sulphuric acid, 24.0 percent of sodium sulphate and 1.8 percent of zinc sulphate.
• the filaments so formed were withdrawn from the bath, stretched in air by 70 percent of their original length, cut into staple fibres and dropped into a solution containing 2 percent of caustic soda where they remained for 5 minutes. The fibres were then separated from the solution in a rotary extractor, washed, impregnated with acid, washed again, finished and dried.
• a process for the production of crimped viscose rayon fibers comprising extruding a viscose containing from percent to percent of cellulose, from 5 percent to 10 percent of caustic soda, more than 0.05 percent of; a modifier and an alkali metal zincate in the proportion of from 0.01 percent to 0.8 percent of zinc based on the weight of the viscose, at a salt figure of between 3 and 14, into a coagulating and regenerating bath containing from 5 percent to 14 percent of sulphuric acid, from 0.5 percent to 4 percent of Zinc sulphate and more than 12 percent of sodium sulphate, to form incompletely regenerated filaments, stretching the filaments by at least 50 peIcent cutting the stretched filaments into staple fibres and crimping the fibres by relaxing the fibres in a solution containing between 1 percent and 5 percent of caustic soda, before completing the regeneration of the cellulose in the fibres.
• a process comprising extruding a viscose contain ing from 7.5 percent to 8.3 percent ofcellulose, caustic soda such that the ratio of caustic soda to cellulose is between 0.7 and 0.9, 0.1 percent to 0.3 percent of polyethylene glycol having an average molecular weight of between 600 and 6,000 and an alkali metal zincate in a proportion of from 0.04 percent to 0.2 percent of zinc based on the Weight of the viscose, at a salt figurev of from 5.5 to 8.5, into a coagulating and regenerating bath containing sulphuric acid in a concentration of from 1.0 to 1.4 times the caustic soda content of the viscose, from 1 to 2 percent of zinc sulphate and between 22 and 24 percent of sodium sulphate, to form incompletely regenerated filaments, stretching the filaments by at least percent of their original length in air, cutting the filaments into staple fibres and crimping the fibres by suspending the fibres in a solution containing between 1.5 and 2.5 percent of ca

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Artificial Filaments (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=10442074

Family Applications (1)

Country Status (6)

Cited By (4)

Citations (7)

• 0
  • NL NL301646D patent/NL301646A/xx unknown
• 1962
  • 1962-12-11 GB GB46652/62A patent/GB1060311A/en not_active Expired
• 1963
  • 1963-12-03 US US327818A patent/US3340340A/en not_active Expired - Lifetime
  • 1963-12-10 DE DEC31643A patent/DE1234917B/de active Pending
  • 1963-12-11 BE BE641106A patent/BE641106A/xx unknown
  • 1963-12-11 AT AT994963A patent/AT250553B/de active

Patent Citations (7)

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