SU1620512A1 - Method of producing sedimentation bath - Google Patents

Abstract

The invention relates to a techno log of viscous fibers and can be used in the production of viscose textile yarn. The invention makes it possible to improve the processability of processing the formed yarn (to reduce the number of cakes with the sodium crystals to be doped from 80 to 60-77 pcs / day, breakage from 1.18 to 1.02-1.15 obr / kg, the number of powders from 0 , 73 to 0.52-0.68 per 10,000 mnites) and dispose of the waste due to the fact that the spent alkali is mixed with concentrated sulfuric acid to a concentration of the latter in a mixture of 25-37 wt.% And the resulting mixture is introduced into the used precipitation bath. 1 tab.

Description

(L

WITH

This invention relates to viscose fiber technology and can be used in the production of viscose textile yarn.

The purpose of the invention is to improve the processability of processing the formed yarn and disposal of waste.

Example 1. A linear density filament of 8.4 tex is formed from viscose containing 8.36% v-cellulose, 6.38% caustic soda, viscosity 40 s and maturity 18.5 ml 1 n. a solution of ammonium chloride through a die plate with 18 holes with a diameter of 0.08 mm in a sedimentation bath containing the components, g / l: sulfuric acid 141; sodium sulfate 275; zinc sulfate 15.5 and hemicellosis 1.1 hydrolysis products 1.1, which are introduced into the precipitation bath as follows. In a static mixer with a continuous length of 1 m, 100 l / h of 93.43% sulfuric acid and i 460 l / h of spent (sewer) alkali containing 10.5 g / l of caustic soda, 9.8 g are metered through rotameters. / l hemicellulose. The reaction mixture obtained by mixing the components to be metered is directed by gravity into a vat of a used precipitation bath and is used as a stock solution of hemicellulose hydrolysis products to strengthen the precipitation bath. The mixture temperature is 85 ° C, the sulfuric acid content is 294.6 g / l (25%), the hemicellulose hydrolysis products are 8.05 g / l. The reaction mixture is mixed with a continuously flowing into a vat of a used precipitation bath from a spinning machine containing 0.85 g / l of hemicellulose hydrolysis products washed from viscose. Strengthened by products

hydrolysis of the hemicellose precipitation bath is pumped out of the tank and added to the total volume of the bath. 1 m - the reaction mixture of the specified composition is used to strengthen the precipitation bath in the amount of 32.2 m by hemicellulose hydrolysis from 0.85 to 1.1 g / l.

The required amount of zinc sulphate is also introduced into the spent precipitation bath. Excess water and sodium sulfate are removed from the bath. The bath is filtered and heated. The precipitation bath thus prepared is used to form a viscose textile yarn.

The thread formed in the form of cakes is characterized by the following indicators.

The number of Easter cakes with prohibited crystals of sodium sulfate 72 pcs / s breakage of the thread during rewind 1.15 obr / kg; the number of intra-boleus defects per conventional thread length of 10,000 m is 0.68,

Examples 2-6 are made analogously to example 1, but with other concentrations of sulfuric acid in a mixture of sewage alkali with concentrated

sulfuric acid. Example 7 is made by a known method with the direct allocation of sewage alkali in the precipitation bath.

The table presents the conditions for hemicellulose hydrolysis, the content of hemicellulose hydrolysis products in the precipitation bath and the properties of the textile yarn.

F o

rmula of invention

The method of preparing a precipitation bath in the production of viscose textile yarn by introducing into a spent sulfuric acid precipitation bath containing sodium and zinc sulphates, concentrated sulfuric acid, zinc sulphate and spent alkali, removing excess water and sodium sulphate, filtering and heating, characterized in that improving the processability of processing the formed yarn and waste disposal; prior to the introduction into the spent precipitation bath, the spent alkali is mixed with concentrated hydrochloric acid until the concentration of the latter in a mixture of 25-37 wt.%.

Claims (1)

Claim A method of preparing a precipitation bath in the production of viscose textile yarn by introducing into the spent sulfuric acid precipitation bath containing sodium and zinc sulfates, concentrated sulfuric acid, zinc sulfate and spent alkali, removing excess water and sodium sulfate, filtering and heating, characterized in that, in order to improving the manufacturability of the molded yarn processing and waste disposal, before being introduced into the spent precipitation bath, the spent alkali is mixed with concentrated sulfur acid to a concentration of the latter in a mixture of 25-37 wt.%. Example Volumetric fierce-containing sulfuric acid The composition of kayaalizapapiyny vein, g / l Temperature * of the reaction mixture ,’’s The composition of the reaction mixture The content of hydrolysis products of hemicellulose in a precipitation bath, g / l The number of Easter cakes with forbidden crystals of sodium sulfate, pgt / day Array · - bone of the thread When rewinding, zbr / ΚΓ The number of internal malformations per 10,000 m of thread Sodium hydroxide Hemitsel lulose Sulfuric acid, Ζ Hydrolysis products of hemicellulose, g / l 1 1: 1,5 10 9.7 • 93 36.8 5.8 m 77 1.12 0.68 2 1: 2 10.6 »1.7 88 31,2 7.6 1.3 66 1.09 0.58 3 1: 2.5 11.8 13.2 83 26.9 9,4 1.5 58 1,02 0.52 4 1: 4,6 (0.5 9.8 85 25 8.05 1,1 72 1.15 0.68 5 1: 3.4 11,4 10.9 89 31 8.42 1.3 66. 1.12 0.63 6 1: 2.5 12.7 11, 9 93 37 8.5 1,5 60 1.05 0.57 1 (Wed) - - - -  - - 0.85 80 1.18 0.73 I