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
• • 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

• the present invention relates to a continuous process for manufacturing viscose products, and more particularly to a proces in which freshly formed viscose threads are aftertreated by passing a large number of such threads through treating zones or in parallel relationship and in a substantially linear direction through successive treating baths at such high speeds that the treatment time in each individual zone or bath is only a few seconds.
• a viscose solution is forced through spinning nozzles or slits into coagulating baths, wherein the product are coagulated and partially regenerated.
• the products are thereafter drawn from the coagulating bath and subjected to various after treatments for the purpose of obtaining an end-product consisting of pure cellulose hydrate, which has been completely freed of residues formed during the decomposition of the viscose and freed from spinbath constituents and from sulphur and other impurities.
• the threads containing the acids and salts from the spinbath are collected on bobbins or in pots and thereafter allowed to remain for several hours so that complete regeneration of the cellulose. or better said, the decomposition of the xanthate is elfected. In certain cases,
• the packages After the packages have been stored for a sufficient time, they are pressure and/or vacuum washed with water to remove the acid and salts and thereafter desulphurized, and if necessary, bleached, and finally dried.
• the threads In this discontinuous process since the threads have been completely regenerated prior to washing, desulphurizing and bleaching, no problem existed with respect to the desulphurizing and bleaching operation. The threads were properly desulphurized and bleached to a pure white product.
• the threads are subjected to the various aftertreatments by passing them around threadstorage, thread-advancing devices in a multiplicity of convolutions. During their passage around the devices they are subjected to the required treatments, such as, partial decomposition, final decomposition, desulphurizing, bleaching and drying.
• the time i not critical because the individual treatment operations consume, for example, from 40 seconds to one minute, which, if acid and washing treatments are given, are sufficient to effect proper desulphurization and bleaching.
• I the individual treating times are limited to only a few seconds, for example, 3 or 4 seconds and certainly not over seconds; Due.
• the threads are insufficientlyregener ated, i. e., the xanthate is not completely decompos d, and therefore when thetnread. is passed through the desulphurizing.bathiononlya few;
• the antha H H I salts should be'washed out, because the presence 'of sajlt will.fappreeiably delay further decomposi tionjof; the last remaining very small amounts" of xanthate residues.
• the desulphurization can be carried out in a reliable man'- ner'that is completely satisfactory for all practical purposes.
• the present-invention when usingone of the normal' desulphurizing agents such as sodium sulphide, it has not beenpossible'to remove allof the sulphur in 'a' con tinuous process involving highspeed treating operations. Because of this,- continuous spinning of this type has not been practical, and h'as'thereforebeen slow in its commercial development. 1 It is therefore the object of the present invention to provide a particular type of after-treatment or series of aftertreatments that can be utilized effectively in this more recently developed continuous spinning system.
• Another object of the invention is to decompose the residual xanthate in the freshly spun threads in several seconds but so completely that the threads can be immediately desulphurized so thoroughly within a very few seconds that no sulphur deposits can be detected in the final product.
• a still further object of the invention is to employ certain materials in the aftertreatment baths that will accelerate the decomposition of the last remaining xanthate in the thread to quickly lower the Xanthate ratio below a critical point, i. e., below .003 or .002.
• the xanthate ratio i. e., the ratio of the number of residual Xanthate groups to the total number of cellulose groups (cameos) is determined by any of the While it is necessary "to eysa r a n manate? s l p esent during he decomposition," as soon as the decomposition of 1 a has reached an advanced'statethe means oila hot dilute acid bath containing sul- 'well known chemical methods.
• the thread in a .dilute sulphuric acid bath cOntaiIling sodium sulphatebelowthej bisulphate ratio for the purpose .of removing theremaining amount of .undecomposedxanthate, the thread can be treated ina bath containing. certain oxidizing decomposing. agents, such as H202, K25 O H0103, H0104, NaOCl, NaClOz, NaNO2, p r t solutions of. sodium hypochlorite or sodium chlorite were.
• certain oxidizing decomposing. agents such as H202, K25 O H0103, H0104, NaOCl, NaClOz, NaNO2, p r t solutions of. sodium hypochlorite or sodium chlorite were.
• a multiplicity of threads are extruded through spinnarets into a normal coagulating spinbath containing sulphuric acid and salts thereof and are then passed in parallel relationship linearly through several baths in the sequence, first, either to a hot dilute sulphuric acid bath having an acid concentration of from 0.5% to 6% and sodium sulphate in a concentration of 1.0% to said bath being maintained at a temperature of from 60 to 95C., or the threads are subjected to further regeneration by the spinbath liquid retained in the threads, but in either case the xanthate ratio can only be lowered to about 0.02 which is insufficient to effect complete desulphurization in the time available. or other suitable treating liquid to remove the salts therefrom.
• the threads are passed through a dilute pure sulphuric acid bath containing sodium sulphate below the bisulphate ratio or through a bath containing an oxidizing agent.
• Thi treatment lowers the xanthate ratio below the critical point, namely, below .002 or at least below .003.
• the thus treated threads are again washed by passing them through a water bath, and are then immediately desulphurized and bleached in successive baths, and finally dried. This process is a continuous one from the beginning to the end, and each of the treatment operations are effected in 3 or 4 seconds, or less, but in any case, never more than 10 seconds.
• the invention is not limited to normal rayon such as 2.5 and 5 illiament denier, but is also applicable to the preparation of thicker products made from viscous such as horsehair, ribbons, and films, and when the expression threads is used in the claims it is intended to cover these other said products.
• a process for the continuous manufacture of viscose threads which comprises extruding a multiplicity of threads through spinnerets into a coagulating bath containing sulphuric acid and salts thereof, passing the threads in parallel relationship linearly through a second bath at such a high speed that the time of passage through the bath is less than ten seconds thereby lowering the xanthate ratio below 0.02, which is insufficient to permit subsequent complete desulphurization, said second bath being maintained at a temperature in the range of 60 C.-95 C.
• a process for the continuous manufacture of viscose threads which comprises extruding a multiplicity of threads through spinnerets into a coagulating bath containing sulphuric acid and salts thereof, passing the threads in parallel relationship linearly through a second bath at such a high speed that the time of passage through the bath is less than ten seconds thereby lowering the xanthate ratio below 0.02, which is insufficient to permit subsequent complete desulphurization, said second bath being maintained at a temperature in the range of 60 C.-95 C.
• a process for the continuous manufacture of viscose threads which comprises extruding a multiplicity of threads through spinnerets into a coagulating bath containing sulphuric acid and salts thereof, passing the threads in parallel relationship linearly through a second bath at such a high speed that the time and passage through the bath is less than ten seconds thereby lowering the xanthate ratio below 0.02, which is insufficient to permit subsequent complete desulphurization, said second bath being maintained at a temperature in the range of 60 C.-95 C.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Artificial Filaments (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)
• Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)

Priority Applications (13)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

Country Status (7)

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• 0
  • DE DENDAT1065564D patent/DE1065564B/de active Pending
  • NL NL65265D patent/NL65265C/xx active
  • BE BE523572D patent/BE523572A/nl unknown
  • BE BE488330D patent/BE488330A/nl unknown
  • NL NL66613D patent/NL66613C/xx active
• 1949
  • 1949-04-07 GB GB9535/49A patent/GB692023A/en not_active Expired
  • 1949-04-21 FR FR984882D patent/FR984882A/fr not_active Expired
  • 1949-05-06 CH CH274860D patent/CH274860A/de unknown
• 1950
  • 1950-06-13 DE DEN1037A patent/DE938032C/de not_active Expired
  • 1950-12-21 US US202149A patent/US2566456A/en not_active Expired - Lifetime
• 1953
  • 1953-10-27 FR FR65615D patent/FR65615E/fr not_active Expired
  • 1953-11-12 CH CH323827D patent/CH323827A/de unknown

Non-Patent Citations (1)

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