Method for preparing bleached pulp by using eucalyptus wood chips

A technology for eucalyptus wood chips and mechanical pulping, applied in pulp beating/refining method, pulp dehydration, water/steam pretreatment, etc., can solve the problem that eucalyptus wood chips cannot be produced normally by pulping technology, and reduce steam consumption and pollution. The effect of less material and non-toxic pollutants

Inactive Publication Date: 2013-10-02
INST OF CHEM IND OF FOREST PROD CHINESE ACAD OF FORESTRY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, raw materials such as eucalyptus wood chips ca

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032]The eucalyptus sawdust is first washed with hot water (temperature 60-70°C) to remove heavy impurities such as sediment, and the washed sawdust is extruded and concentrated to 40% by a twin-screw extruder (compression ratio is 4:1 by volume) The absolute dry material accounts for the total weight of the wet material, the same below), and then use steam at 100~105°C to steam at normal pressure for 15 minutes. Ratio (volume ratio 4:1) extrusion concentration to more than 50% concentration, remove the water-soluble extract from the raw material as much as possible, then add alkaline hydrogen peroxide solution for chemical impregnation, the impregnation conditions are: the amount of hydrogen peroxide 2.0% wt (for absolute dry materials), 2.5% wt of sodium hydroxide (for absolute dry materials), 0.2% wt of DTPA (for absolute dry materials), 0.6% wt of sodium silicate (for absolute dry materials), The impregnating pulp concentration (weight of absolute dry material accounts fo...

Embodiment 2

[0035] The eucalyptus sawdust is first washed with hot water (temperature 60-70°C) to remove heavy impurities such as sediment, and the washed sawdust is extruded and concentrated to 40% by a twin-screw extruder (compression ratio is 4:1 by volume) The absolute dry material accounts for the total weight of the wet material, the same below), and then use steam at 100~105°C to steam at normal pressure for 15 minutes. Ratio (volume ratio 4:1) extrusion concentration to more than 50% concentration, remove the water-soluble extract from the raw material as much as possible, then add alkaline hydrogen peroxide solution for chemical impregnation, the impregnation conditions are: the amount of hydrogen peroxide 3.0% wt (for absolute dry material), 3.5% wt of sodium hydroxide (for absolute dry material), 0.25% wt of DTPA (for absolute dry material), 0.25% wt of organic phosphonate stabilizer (for absolute dry material) material), impregnating pulp concentration (weight of absolute dry ...

Embodiment 3

[0038] The eucalyptus sawdust is first washed with hot water (temperature 60-70°C) to remove heavy impurities such as sediment, and the washed sawdust is extruded and concentrated to 40% by a twin-screw extruder (compression ratio is 4:1 by volume) The absolute dry material accounts for the total weight of the wet material, the same below), and then use steam at 100~105°C to steam at normal pressure for 15 minutes. Ratio (volume ratio 4:1) extrusion concentration to more than 50% concentration, remove the water-soluble extract from the raw material as much as possible, then add alkaline hydrogen peroxide solution for chemical impregnation, the impregnation conditions are: the amount of hydrogen peroxide 3.0% wt (for absolute dry material), 3.5% wt of sodium hydroxide (for absolute dry material), 0.25% wt of DTPA (for absolute dry material), 0.25% wt of organic phosphonate stabilizer (for absolute dry material) material), impregnating pulp concentration (weight of absolute dry ...

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Abstract

The invention discloses a method for preparing bleached pulp by using eucalyptus wood chips, and belongs to the fields of pulping and papermaking. The method comprises the following steps: orderly washing, dewatering and presteaming a eucalyptus wood material, carrying out double helix extrusion, chemical impregnation and high-consistency refining, eliminating, washing and the like. A double helix extruder with a variable pitch and a variable diameter is adopted in extrusion and concentration treatment of the material before defibrination; the damage of the traditional extrusion tearing machine to a fiber is avoided; the quality of the prepared pulp is similar to that of the pulp prepared by qualified chips; the bulk of the pulp can achieve over 3.4 cm<3>/g; the whiteness can achieve over 76% ISO (international standardization organization); effective utilization of the eucalyptus wood chips in the fields of pulping and papermaking is achieved; alkaline hydrogen peroxide which is friendly to the environment is adopted in the craft process; a fewer of pollutants are generated in the pulping process and are non-toxic; instant bleaching and subsequent bleaching reaction are achieved by effectively utilizing the heat energy generated in the pulping process; and steam consumption is reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical mechanical pulping, in particular to a process for preparing bleached mechanical pulp by using eucalyptus sawdust. [0002] Background technique [0003] my country is a big country in the production and consumption of paper and cardboard, and the production and consumption of paper and cardboard both rank first in the world. The paper industry is an important basic raw material industry in my country's national economy, with a high degree of industrial correlation, which is of great significance to the development of the national economy. Since the reform and opening up, my country's paper industry has made great progress. In 2011, my country's paper and cardboard output exceeded 110 million tons, reaching 110.343 million tons, surpassing the United States for four consecutive years and ranking first in the world. However, there are still many difficulties and problems in my country's papermak...

Claims

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Application Information

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IPC IPC(8): D21C1/02D21C9/02D21C9/18D21D1/30
Inventor 房桂干邓拥军韩善明李红斌焦健梁芳敏丁来保盘爱享苗丹丹沈葵忠施英乔李萍庄国俊
Owner INST OF CHEM IND OF FOREST PROD CHINESE ACAD OF FORESTRY
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