Method for producing cotton pulp used for cellulose triacetate by two-step stewing technology

A technology of cellulose triacetate and secondary cooking, applied in pulping of cellulose raw materials, pulping with inorganic alkali, fiber raw material treatment, etc., can solve the problem of high content of dichloromethane extract, achieve excellent clarity, improve Quality, less dust effect

Active Publication Date: 2013-04-03
山东银鹰化纤有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

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Method used

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  • Method for producing cotton pulp used for cellulose triacetate by two-step stewing technology
  • Method for producing cotton pulp used for cellulose triacetate by two-step stewing technology
  • Method for producing cotton pulp used for cellulose triacetate by two-step stewing technology

Examples

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Embodiment 1

[0036] A method for producing cotton pulp for cellulose triacetate by a secondary cooking process, the specific operations are as follows:

[0037] (1) Material selection, cotton opening, and impurity removal process: select three types of first-class cotton linters with a maturity ≥ 80%, and use a cotton opener to tear the linters, then loosen and remove impurities through the impurity remover, Then transfer to the cotton extruder, after selection and removal of impurities, it is sent to the screw press and impregnation through the cyclone separator;

[0038] (2) One-time alkali mixing, impregnation, and cooking process: the temperature of alkali mixing is controlled at 80°C, the total alkali is 5.2% relative to the dry pulp weight in terms of NaOH, the ratio of alkali solution is 1: 4.5%, and the relative dry pulp weight of hydrogen peroxide is 0.5%, the scouring agent is 0.5% relative to the weight of the absolute dry pulp; it is sprayed with lye in the cyclone separator, s...

Embodiment 2

[0061] A method for producing cotton pulp for cellulose triacetate by a secondary cooking process, the specific operations are as follows:

[0062] (1) Material selection, cotton opening, and impurity removal process: select three types of first-class cotton linters with a maturity ≥ 80%, and use a cotton opener to tear the linters, then loosen and remove impurities through the impurity remover, Then transfer to the cotton extruder, after selection and removal of impurities, it is sent to the screw press and impregnation through the cyclone separator;

[0063] (2) One-time alkali blending, impregnation, and cooking process: the temperature of alkali blending is controlled at 85°C, the total alkali is 6.3% relative to the dry pulp weight in terms of NaOH, the ratio of alkali solution is 1:5.2%, and the relative dry pulp weight of hydrogen peroxide is 1.0%, the scouring agent is 1% relative to the weight of the absolute dry pulp; it is sprayed with lye in the cyclone separator, ...

Embodiment 3

[0086] A method for producing cotton pulp for cellulose triacetate by a secondary cooking process, the specific operations are as follows:

[0087] (1) Material selection, cotton opening, and impurity removal process: select three types of first-class cotton linters with a maturity ≥ 80%, and use a cotton opener to tear the linters, then loosen and remove impurities through the impurity remover, Then transfer to the cotton extruder, after selection and removal of impurities, it is sent to the screw press and impregnation through the cyclone separator;

[0088] (2) One-time alkali blending, impregnation, and cooking process: the temperature of alkali blending is controlled at 83°C, the total alkali is 5.7% relative to the dry pulp weight in terms of NaOH, the alkali liquor ratio is 1: 4.8%, and the relative dry pulp weight of hydrogen peroxide is 0.7%, the scouring agent is 0.7% relative to the dry pulp weight; it is sprayed with lye in the cyclone separator, screw extruded, an...

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Abstract

The invention discloses a method for producing cotton pulp used for cellulose triacetate by a two-step stewing technology. The method comprises the following steps of raw material selection, cotton opening, impurity removal, primary alkali blending, dipping, stewing, secondary alkali blending, dipping, stewing, pre-degritting, pre-pulping, concentration, chlorine dioxide bleaching, hydrogen peroxide bleaching, alkaline extraction, acid treatment, after degritting, after pulping, pulp processing, and finishing. The method has simple processes, utilizes cotton linter as a raw material, adopts a rotary spherical digester two-step stewing technology, carries out primary stewing of impurities in cotton linter by an alkali, hydrogen peroxide and stewing assistants having appropriate concentrations, extrudes a stewing raffinate by steam excess pressure after heat preservation, carries out secondary heat-preservation stewing by re-feeding of certain amounts of the alkali, hydrogen peroxide and the stewing assistants, realizes cotton pulp dichloromethane extract content of 30 to 90PPM, has a waste water COD discharge amount of 20250 to 25050mg/l in the whole pulping process, and reduces sewage treatment stress.

Description

technical field [0001] The invention relates to a production process of cellulose triacetate cotton pulp, in particular to a method for producing cotton pulp for cellulose triacetate by using a secondary cooking process, and belongs to the field of cotton pulp production. Background technique [0002] Due to its toughness, high tensile strength, high compressive strength, and good heat resistance, triacetate cellulose is an indispensable part of the production of polarizers for liquid crystal displays. With the rapid development of liquid crystal displays, triacetate fibers Su put forward higher requirements. The most important raw material for the preparation of cellulose triacetate is cotton pulp, and the most difficult problem in cotton pulp is that the content of dichloromethane extract meets the requirements, which affects the processing and use performance of polarizers for liquid crystal displays. [0003] The Chinese patent titled "Cotton Pulp Production Process fo...

Claims

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Application Information

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IPC IPC(8): D21H11/12D21C3/02D21C3/22
Inventor 曹知朋陈忠国臧贻朋郑春友吕兴华唐逢
Owner 山东银鹰化纤有限公司
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