Preparation method of cellulosic fibers

Abstract

The invention discloses a preparation method of cellulosic fibers. The preparation method includes the following steps that 1, cellulose pulp is mixed with an NMMO water solution with the mass concentration of 60%-85%, preferably 70%-76% to obtain a uniform mixture; 2, the obtained uniform mixture is subjected to dehydration swelling and dissolution defoaming to obtain a cellulose spinning solution; 3, the obtained cellulose spinning solution is filtered and subjected to heat exchange and then enters a spinning machine, after the cellulose spinning solution is extruded through a spinning assembly and air-cooled, the cellulose spinning solution enters a solidification system and is solidified in an NMMO solidification bath with the mass concentration larger than 50% and smaller than 72%, and nascent fibers are obtained; 4, the obtained nascent fibers are washed to obtain cellosilk bundles, and then the cellulosic fibers are obtained through subsequent section treatment. Equipment investment can be greatly reduced, the process is simplified, energy consumption and industrialization cost are reduced, safety production is promoted, the homogeneity and mechanical performance of the fibers are improved, and therefore the preparation method is more suitable for efficient low-consumption industrial production.

Description

technical field [0001] The invention belongs to the technical field of cellulose, and in particular relates to a preparation method of cellulose fibers. Background technique [0002] In the process of dissolving cellulose with N-methylmorpholine-N-oxide (NMMO) aqueous solution to prepare cellulose fibers, the swelling, dissolving process and effect of NMMO on cellulose are directly related to the stability of spinning and the performance of the final product ; And the concentration of the spinning dope and whether the process is energy-saving are directly related to the economic benefits and industrialization of the process technology. In view of this, in industrial production, an energy-saving and efficient method for preparing cellulose fibers is particularly important. [0003] Prior art In the process of cellulose fiber preparation, the concentration of NMMO aqueous solution to be recovered is low, as described in CN101089262A and CN1318115A, generally 10%-30%, and the ...

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Problems solved by technology

[0003] Prior art In the process of cellulose fiber preparation, the concentration of NMMO aqueous solution to be recovered is low, as described in CN101089262A and CN1318115A, generally 10%-30%, and the concentration of raw material NMMO aqueous solution required for stock solution preparation is high, as described in CN1468889A and CN1635203A , generally 80%-88%, the amount of evaporated water required for recovery is huge, and energy-saving multi-effect evaporation equipment is usually used; The large investment in equipment makes the production cost too high, making it difficult to achieve high-efficiency and low-consumption industrial production

[0004] In addition, a single low-concentration coagulation method can easily lead to severe coagulation, resulting in the formation of a skin-core structure in the fiber, which is not conducive to the homogeneity and mechanical properties of the fiber; moreover, the high-concentration NMMO aqueous solution required for the preparation of the stock solution exists during evaporation, storage, and transportation. Safety risks, there is repeated energy consumption in the preparation of stock solution, and the equipment and process of stock solution preparation are too cumbersome

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