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CN-122013339-A - Method for preparing cellulose diacetate fibers by taking waste filter rods as raw materials

CN122013339ACN 122013339 ACN122013339 ACN 122013339ACN-122013339-A

Abstract

The invention relates to a method for preparing cellulose diacetate fibers by taking waste filter rods as raw materials, which comprises the steps of quantitative humidification, low-cutting-rate extrusion rubbing paper stripping, separation of formed paper, vacuum drying to remove triacetin, dissolution, graded filtration and spinning. The invention has the advantages that the pretreatment process of quantitative humidification and low-cutting-rate extrusion rubbing paper stripping effectively improves the integrity rate of the formed paper, reduces the generation amount of small-size fragments, combines vacuumizing and drying to replace hot water washing, avoids micron-sized fragment dissociation, stably improves the filtration flux of slurry, prolongs the replacement period of filter materials, and radically solves the core bottleneck of quick attenuation of the filtration flux in the traditional process.

Inventors

  • HUANG HAIJIAN
  • ZHANG LI
  • SHI HAOXUAN
  • CAO ZHIXIANG

Assignees

  • 南通醋酸纤维有限公司
  • 珠海醋酸纤维有限公司
  • 昆明醋酸纤维有限公司

Dates

Publication Date
20260512
Application Date
20260109

Claims (7)

  1. 1. The method for preparing the cellulose diacetate fiber by taking the waste filter rod as the raw material is characterized by comprising the following steps in sequence: S1, quantitatively humidifying a waste filter stick; S2, extruding, rubbing and stripping paper with low cutting rate on the humidified waste filter stick; S3, separating the formed paper; s4, vacuumizing and drying the waste filter stick separated from the formed paper to remove triacetin; s5, dissolving the dried waste filter stick in acetone to form slurry; s6, carrying out classified filtration on the slurry formed in the step S5, wherein the final stage of filtration precision is 1-10 mu m; and S7, spinning the slurry after filtering in the step S6 to obtain the cellulose diacetate fiber.
  2. 2. The method according to claim 1, wherein in the step S1, the quantitative humidification is to treat the waste filter rod by quantitatively spraying deionized water, the water content of the treated waste filter rod is 40% -80%, and the formed paper on the surface of the waste filter rod maintains the tensile strength of more than 30%.
  3. 3. The method of claim 1, wherein in step S2, the low-cut-rate extrusion stripping is performed using an extrusion stripper with a shear rate of 100-2000S -1 to maintain the morphological integrity of the formed paper after stripping.
  4. 4. The method according to claim 1, wherein in step S3, the separation of the molded paper is performed by one or more selected from the group consisting of centrifugal separation, pneumatic separation, and negative pressure adsorption.
  5. 5. The method according to claim 1, wherein in step S4, the conditions of the vacuum drying are a temperature of 110-160 ℃ and a pressure of 0.3-10kPa, and the vacuum drying equipment includes, but is not limited to, a double cone rotary vacuum dryer, a rake vacuum dryer, a square vacuum dryer, a cylinder vacuum dryer or a vacuum drying oven.
  6. 6. The method of claim 1, wherein in step S5, the slurry is at a concentration of 26.5% -28.5%.
  7. 7. The method according to claim 1, wherein in step S7, the spinning is performed by dry spinning, and the filtered slurry is extruded through a wire hole and then volatilized in a spinning channel to form the cellulose diacetate fiber.

Description

Method for preparing cellulose diacetate fibers by taking waste filter rods as raw materials Technical Field The invention relates to the technical field of recycling of filter sticks for waste cigarettes, in particular to a method for preparing cellulose diacetate fibers by taking a cellulose acetate filter stick for waste cigarettes as a raw material. Background The recycling of the acetate fiber filter stick for the waste cigarettes is an important research direction in the fields of resource recycling and environmental protection, and has the core value of regenerating cellulose diacetate (hereinafter referred to as acetate fiber) in the waste filter stick into usable fibers so as to reduce resource waste and environmental pollution. The traditional recovery process generally adopts a route of 'soaking, paper stripping, hot water washing and drying', but has the following core problems: 1) The formed paper fragments are seriously polluted, namely, the tensile strength of the formed paper is too low due to long-time soaking, and a large number of small-size formed paper fragments are generated by tearing the paper at a high rotating speed; 2) The filtration flux decays rapidly, in the hot water washing process, the formed paper fragments are further dissociated into micron-sized particles, and the subsequent slurry is filtered to block fine filtration equipment (such as a 1-10 mu m filter press), so that the filtration flux decays rapidly; 3) The cost is high, the batch production is difficult, the filter material consumption is large, the sewage discharge is large, the recovery efficiency is low, and the industrialized batch production is difficult to realize. Therefore, in view of the above, there is a need for a method for preparing cellulose diacetate fibers that can solve the problems of excessive formed paper chips, fast filtration flux attenuation, high cost and difficult batch production in the conventional waste filter rod recovery process. Disclosure of Invention The invention aims to solve the problems in the prior art and provides a method for preparing cellulose diacetate fibers by taking waste filter rods as raw materials. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The method for preparing the cellulose diacetate fiber by taking the waste filter rod as the raw material sequentially comprises the following steps: S1, quantitatively humidifying a waste filter stick; S2, extruding, rubbing and stripping paper with low cutting rate on the humidified waste filter stick; S3, separating the formed paper; s4, vacuumizing and drying the waste filter stick separated from the formed paper to remove triacetin; s5, dissolving the dried waste filter stick in acetone to form slurry; s6, carrying out classified filtration on the slurry formed in the step S5, wherein the final stage of filtration precision is 1-10 mu m; and S7, spinning the slurry after filtering in the step S6 to obtain the cellulose diacetate fiber. Preferably, the quantitative humidification is to treat the waste filter rod by adopting a quantitative deionized water spraying mode, the water content of the treated waste filter rod is 40% -80%, and the formed paper on the surface of the waste filter rod keeps the tensile strength above 30%. Preferably, the low-cutting-rate extrusion rubbing paper stripping is performed by adopting an extrusion rubbing paper stripping machine, and the shearing rate is 100-2000s -1 so as to maintain the morphological integrity of the formed paper after stripping. Preferably, the mode of separating the forming paper is selected from one or more of centrifugal separation, pneumatic separation and negative pressure adsorption. Preferably, in the step S4, the vacuumizing and drying conditions are that the temperature is 110-160 ℃ and the pressure is 0.3-10kPa, and the vacuumizing and drying equipment is selected from a double-cone rotary vacuum dryer, a rake type vacuum dryer, a square vacuum dryer, a cylinder vacuum dryer or a vacuum drying box. Preferably, in step S5, the concentration of the slurry is 26.5% -28.5%. Preferably, in step S7, the spinning adopts a dry spinning process, and the filtered slurry is extruded through a filament hole and then volatilizes the solvent in a spinning channel to form the cellulose diacetate fiber. Due to the adoption of the technical scheme, the beneficial effects obtained by the invention include: 1. The pretreatment process of quantitative humidification and low-cutting-rate extrusion rubbing paper stripping ensures that the integrity rate of the formed paper is effectively improved, and the generation amount of small-size fragments is reduced; 2. the invention can eliminate the sewage pollution generated by hot water washing, obviously reduce the environmental protection pressure, realize the green production mode of resource recycling and take into account the economic value and the ecological benefit; 3. The inve