Pulping process for grinding wood pulp of cotton wood by mechanical abrader

Abstract

The invention discloses a cotton wood stone ground wood pulping process comprising the following steps of: (1) log sawing and skinning; (2) jordaning with alkali in a wood grinder; (3) screening by a pressure screen; (4) screenings jordaning with alkali in a conical mill; and (5) hydrogen peroxide bleaching. The invention is characterized in that: the wood grinder grindstone of the step (2) adopts bush roll with 4 mesh by primary burring; in the screening process by the pressure slot screen of the step (3), the pulp intake pressure is 0.2-0.4 MPa, the differential pressure is 0.02-0.07 MPa, the pulp intake consistence is 2.5-4.5%, the screenings output volume is 22-35%, the thickness of the screen cut is 0.15-0.35 mm; sodium hydroxide is added in the conical mill of the step (4) to grind screenings, wherein the consumption of the sodium hydroxide is 0.6-0.8% (based on weight percent of oven dry stock), the alkali liquor is added in the pulp intake tank of the conical mill with 40-50 g / l of the alkali liquor concentration, 3.1%-4.54% of jordaning consistency, 0.2-0.3 MPa of jordaning pressure, accordingly, the beating degree of the pulp ground by the conical mill can be increased by 8-12 DEG SR. The pulping process of the invention has advantages of high yield, less pollution, low cost, and the obtained pulp is applicable for paper with various specifications such as pigment offset paper, low weight paper, card paper, color newsprint paper, or the like.

Description

Technical field: [0001] The invention relates to the pulping field of groundwood pulp in papermaking, in particular to a pulping process of poplar mechanical groundwood pulp. Background technique: [0002] Ordinary stone ground wood pulp is generally processed by log refining, vibrating flat screen, desander tank, CX sieve, desander purification, bleaching and other processes. Pulping quality is poor, such as: whiteness after bleaching ≤ 60% (ISO), fracture length ≤ 2.0Km, high content of fiber bundles, and pine wood contains resin, which has adverse effects on papermaking and paper quality, SGW Pulp is only suitable for low-grade newsprint, not high-grade cultural paper. Invention content: [0003] In order to overcome the deficiencies of ordinary millstones and wood mills, the purpose of the present invention is to provide a kind of high pulp yield, low pollution, low cost, and pulp quality that can meet the requirements of color glue paper, light paper, yellow cardboar...

AI Technical Summary

Problems solved by technology

Pulping quality is poor, such as: whiteness after bleaching ≤ 60% (ISO), fracture length ≤ 2.0Km, high content of fiber bundles, and pine wood contains resin, which has adverse effects on papermaking and paper quality, SGW Pulp is only suitable for low-grade newsprint, not high-grade cultural paper