Method for preparing pulp from hemp raw material

Abstract

The invention relates to the technical field of pulp preparation, particularly to a method for preparing pulp from a hemp raw material. The preparation method comprises: 1, pretreatment of a hemp rawmaterial: (1) enzyme cold stacking, (2) oxygen bleaching treatment, (3) water washing neutralization, (4) softening treatment, (5) drying, and (6) wet loosening; and 2, preparation of pulp: (1) mixingand dissolving caustic soda flakes with a proper amount of water, (2) adding a reinforcing wetting agent, a toughening agent and a dispersing defoaming agent, and uniformly stirring, (3) adding the pretreated hemp raw material, and stirring, and (4) drying again to finally obtain the hemp pulp. According to the present invention, the new process concept sequentially comprising cold stacking degumming of the hemp raw material and the pulp preparing is used, such that the prepared pulp has characteristics of high solubility and high stability, the conditions are created for preparing viscose fibers with characteristics of high dye uptake, high elongation at break and good toughness, and the preparation method has characteristics of simpleness, mild conditions, substantially reduced alkali consumption, sewage treatment load reducing and easy environment improving.

Description

technical field [0001] The invention relates to the technical field of pulp preparation, in particular to a method for preparing pulp from hemp raw materials. Background technique [0002] Hemp is an important textile raw material. Hemp fiber is the thinnest cushion among all kinds of fibers. Hemp fiber is popular among consumers for its moisture absorption, breathability, antibacterial, and anti-ultraviolet properties. The shape of the cross section of hemp fiber is more complicated than that of flax, cotton and wool, including triangle, polygon, oblate, waist and so on. The middle cavity is often different from the shape. When the light shines, part of it forms multi-layer refraction or is absorbed, and a large amount of full reflection is formed, so that the hemp fabric not only looks soft and lustrous, but also has a good anti-ultraviolet radiation function. The fineness of the single fiber of hemp is about 2 to 3 times that of hemp, which is close to that of cotton, an...

AI Technical Summary

Problems solved by technology

Although the above-mentioned patent adopts the plucking machine to remove impurities and loosen the short fibers after cutting, which simplifies the process steps, and adopts enzyme treatment before alkali cooking to improve the cooking efficiency, but there are the following disadvantages. One is that it uses alkaline pectin Enzyme treatment is carried out by soaking in enzyme solution. When the amount of alkali is too large, the molecular chains of cellulose crystals will be slightly damaged, resulting in a decrease in the ordered cellulose structure and a decrease in cellulose crystallinity. The COD value of the discharged waste liquid is high, which is not conducive to environmental protection; the second is that the cooking temperature is 140 ° C ~ 160 ° C, the holding time is 70 min ~ 80 min, high temperature cooking, the damage to cellulose and hemicellulose is relatively large; the third is the above patent Although the hemp fiber is treated with enzymes, because the hemp fiber has more crystallization regions than ordinary natural fibers, it is difficult for some additives to penetrate into the fiber, resulting in a small specific surface area of ​​the fiber, and the fiber’s subsequent adsorption of additives is poor. The specific surface area of ​​the spun viscose fiber will be small, the dye uptake rate is low, the elongation at break of the fiber is low, and the toughness is poor

Images