Classifications

• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/02—Synthetic cellulose fibres
  • D21H13/08—Synthetic cellulose fibres from regenerated cellulose
• • 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
  • D01D4/00—Spinnerette packs; Cleaning thereof
  • D01D4/02—Spinnerettes
• • 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

Definitions

• the filaments which have a primary swelling value of from 1900 to 10,000, are formed by the viscose process wherein viscose is spun through a spinneret into a coagulating bath of 8-18 g./l, sulfuric acid, 0.2-1.0 g./l. zinc sulfate and 20-100 g./l. sodium sulfate at a temperature of from 35 C.
• This invention relates to a process for manufacturing rayon paper or nonwoven fabric by a wet system.
• a process for manufacturing rayon paper or nonwoven fabric by a wet system which comprises dispersing in water staple fibres formed from stable incompletely regenerated cellulose filaments obtained by the viscose process, said filaments having a primary swelling value of from 1,900 to 10,000 and being obtained by spinning viscose through a spinneret having an effective length to diameter ratio for the holes such that the Barus effect on the viscose solution is small and thereafter forming paper or a nonwoven fabric from the resulting dispersion.
• the process according to the invention combines the process of rayon making with that of paper making.
• a sheet of nonwoven fabric is formed on a sieving machine after the filaments have been cut and dispersed in Water.
• the filaments have a residual -value of 15 or more and preferably of from 15 to 40.
• the method used for determining the primary swelling value of incompletely regenerated cellulose filaments is as follows: The filaments (ca. 0.5 gram as dry cellulose) are steeped in distilled Water at 20 C. for 5 minutes. The swollen filaments thus obtained are centrifuged for 3 minutes by a force of 1,000 G and the weight (W) of the hydroextracted filaments is obtained. Thereafter the filaments are bone-dryed and the weight (W of the bonedry filaments is obtained.
• the primary swelling value is calculated from the following formula:
• Certain kinds of liquids having a high viscosity including a viscose solution, expand when extruded from a capillary.
• This phenomenon e.g., the diameter of a spun filament is larger than that of the spinning orifice, is known as the Barns effect.
• the degree of expansion of a viscose solution corresponds inversely to the length-to-diameter ratio of a capillary.
• the length-todiameter ratio of a hole is generally from 20 to 30, while the effective hole-length of a usual metal spinneret is generally only about twice the spinneret hole-diameter. This fact means that viscose filaments extruded from a normal glass spinneret expand less than those extruded from a usual metal spinneret, As the result, in the case of a glass spinneret, holes can be distributed more densely than in the case of a usual metal spinneret.
• a bundle of spun filaments retains a certain quantity of bath liquor in it during its travel in the bath after extrusion from a spinneret.
• the retained volume of bath liquor is proportional to the actual surface area of the spinneret, within Which the total number of holes is drilled. Therefore, the bundle extruded from a normal glass spinneret retains less bath liquor than that extruded from a usual metal spinneret, if both spinnerets have the same number of holes. If so, when spun in the same acid concentration bath, the quantity of bath liquor which is eifective per filament is considerably less in the case of a normal glass spinneret than in the case of a usual metal spinneret.
• the glass spinneret itself is not indispensable in the present process.
• the present invention can use any spinneret which makes the Barns effect of a viscose solution small. It is preferable in the process of the present invention to use a spinneret in which the effective lengthto-diameter ratio of holes is more than five.
• the primary swelling value of incompletely regenerated filaments is apt to decrease after leaving the spinning bath, owing to the action of acid liquor still remaining on them.
• the concentration of sodium sulphate in the solution should be kept more than 50 g./l., otherwise the filaments may stick together and sulficient dispersion of the cut fibres will not be attained.
• Viscose with a DR of 460, a 'y-value of 60 and a viscosity giving rise to a falling-ball measurement of 270 seconds was spun using a glass spinneret having a lengthto-diameter ratio of 20 into a spinning bath containing 16 g./l. of sulphuric acid, 0.4 g./l. of zinc sulphate and 40 g./l. of sodium sulphate at a temperature of 16 C.
• Viscose with a DR of 650, a -value of 65 and a viscosity giving rise to a falling-ball measurement of 490 seconds was spun using a glass spinneret having a lengthto-diameter ratio of into a spinning bath containing 14 g./l. of sulphuric acid, 0.6 g./l. of zinc sulphate and 60 g./l. of sodium sulphate at a temperature of 30 C., and incompletely regenerated filaments, having a residual value of 24 and a primary swelling value of 3,100%, were obtained.
• the resulting filaments were cut without drying, dispersed immediately in water and shaped into a paper sheet.
• the wet sheet was bleached and dried after moderate pressing at a pressure of 20' kg./cm.
• the nonwoven fabric thus obtained had a drape of a plane fabric.
• the characteristics of the product are shown in the following table.
• EXAMPLE 3 Viscose similar to that used in Example 2 was similarly spun into a spinning bath containing 13 g./l. of sulphruic acid, 0.7 g./l. of Zinc sulphate and 60 -g./l. of sodium sulphate at a temperature of 30 C., and incompletely regenerated filaments, having a residual y-value of 29 and a primary swelling value of 6,l90%, were obtained.
• the resulting filaments were out without drying, dispersed immediately in water and shaped into a paper sheet.
• the wet sheet was bleached and dried after moderate pressing at a pressure of 15 kg./ cm.
• the nonwoven fabric thus obtained had a drape of a cotton flannel.
• the characteristics of the product are shown in the following table.
• EXAMPLE 4 Viscose similar to that used in Example 2 was similarly spun into a spinning bath containing 12 g./l. of sulphuric acid, 0.8 g./l. of zinc sulphate and 80 g./l. of sodium sulphate at a temperature of 30 C., and incompletely regenerated filaments, having a residual -value of 33 and a primary swelling value of 9,200, were obtained.
• the resulting filaments were cut without drying, dispersed immediately in water and shaped into a paper sheet.
• the Wet sheet was bleached and dried after moderate pressing at a pressure of 5 kg./cm.
• the nonwoven fabric thus obtained had a drape like that of towelling.
• the charac teristics of the product are shown in the following table.
• Viscose similar to that used in Example 2 was spun into a low acid spinning bath containing 13.3 g./l. of sulphuric acid, 0.6 g./l. of zinc sulphate and 60 g./l. sodium sulphate at a temperature of 30C., and incom pletely regenerated filaments, having a residual 'y-Value of 26 and a primary swelling value of 3,300, were obtained. Similar filaments were treated with an aqueous solution containing g./l. of sodiumsulphate at a temperature of 15 0., immediately after leaving the spinning bath and the primary swelling value of the incompletely regenerated filaments thus obtained was 4,400, in comparison with 3,300 of those obtained without the said treatment.
• a process for manufacturing rayon paper or nonwoven fabric by a wet system which comprises dispersing in water staple fibres formed from stable incompletely regenerated cellulose filaments obtained by the viscose process, said filaments having a primary swelling value of from 1,900 to 10,000 and being obtained by spinning viscose having a DR of more than 450 through a spinneret having an effective length to diameter ratio for the holes of the spinneret of more than five into a coagulating bath which contains from 8 to 18 grams per litre of sulphuric acid, from 0.2 to 1.0 gram per litre of zinc sulphate and from 20 to 100 grams per litre of sodium sulphate at a temperature of from 15 to 35 C. and thereafter forming paper or a nonwoven fabric from the resulting dispersion.

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• 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)

Applications Claiming Priority (1)

Publications (1)

Family

ID=12188480

Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (1)

• 1968
  • 1968-03-12 GB GB02093/68A patent/GB1178811A/en not_active Expired
  • 1968-04-05 US US719247A patent/US3553078A/en not_active Expired - Lifetime
  • 1968-04-17 DE DE1771180A patent/DE1771180C3/de not_active Expired
  • 1968-04-18 AT AT379568A patent/AT281585B/de not_active IP Right Cessation
  • 1968-04-19 FR FR1560870D patent/FR1560870A/fr not_active Expired
  • 1968-04-24 CH CH607668A patent/CH492076A/de not_active IP Right Cessation
  • 1968-04-25 SE SE05580/68A patent/SE354882B/xx unknown
  • 1968-04-25 BE BE714231D patent/BE714231A/xx unknown
  • 1968-04-25 NL NL686805898A patent/NL139043B/xx unknown

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