Production method of special refined cotton with high uniform polymerization degree

Abstract

The invention discloses a production method of special refined cotton with high uniform polymerization degree. The production method comprises the following steps: S1, material selection and preparation: selecting cotton linters with the fiber length of 10-12mm and the maturity of over 80% as a refined cotton raw material; s2, cotton opening and impurity separation, wherein the cotton linters are put into an opener to be opened, then the cotton linters are put into an impurity removing machine, and sand, stone, cotton hulls, hair and other foreign impurities mixed into the cotton linters are separated from the cotton linters; s3, preparing a cooking liquor: mixing a sodium hydroxide solution, copper sulfate, a cyclic ketone compound, a stabilizer, sulfur trioxide and hydrogen peroxide according to a certain ratio to obtain the cooking liquor; and S4, dipping: putting the cotton linters into the cooking liquor for dipping. The bleaching device has the beneficial effects that the bleaching liquid is added into the bleaching pool for three times, and the temperature of the bleaching pool is quickly adjusted to the set temperature after the bleaching liquid is added each time, so that the temperature of the bleaching pool can be ensured not to change greatly, and the problem that the bleaching effect is influenced due to the fact that the temperature change is large can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of refined cotton production, and in particular to a method for producing special refined cotton with high uniform polymerization degree. Background Art

[0002] Refined cotton is a white flocculent material that is uniform and loose, and free of impurities such as sawdust, bamboo dust, sand, oil, metal, etc. Its raw material is cotton linters, and its main chemical components are cellulose, lignin and hemicellulose.

[0003] For example, a method for producing refined cotton with application number CN10253523A and announcement date 2012.0.7.04 includes the following steps: opening, removing impurities and steaming cotton linter raw materials to obtain a first pulp; debonding and removing sand from the first pulp to obtain a second pulp; bleaching, acid-treating and drying the second pulp to obtain refined cotton.

[0004] In the above and prior art, when producing refined cotton, in the bleaching process, a large amount of bleaching liquid is usually directly added to the bleaching tank at one time, which will cause the temperature of the bleaching tank to drop suddenly. The temperature of the bleaching tank will change greatly, which will affect the bleaching effect. In addition, in the prior art, when boiling cotton linters, a single boiling method is usually used, which makes it difficult to depolymerize the refined cotton pulp. Therefore, it is urgent to design a method for producing special refined cotton with high uniform polymerization degree to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a method for producing special refined cotton with high uniform polymerization degree to solve the above-mentioned shortcomings in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A method for producing special refined cotton with high uniform polymerization degree comprises the following steps: S1. Material selection and preparation: Select cotton linters with a fiber length of 10-12mm and a maturity of more than 80% as refined cotton raw materials; S2. Opening and separation of impurities: Put the cotton linters into the cotton opener to loosen them, and then put them into the impurity remover to separate the sand, stone, cotton shell, hair and other impurities mixed in the cotton linters from the cotton linters; S3, preparing a cooking liquid: mixing a certain ratio of sodium hydroxide solution, copper sulfate, a cyclic ketone compound, a stabilizer, sulfur trioxide and hydrogen peroxide to obtain a cooking liquid; S4, soaking: soaking the cotton linters in the cooking liquid; S5, cooking: pouring the soaked cotton linters and the cooking liquid into a steaming ball for cooking in two stages, and then cooling to obtain a first slurry; S6, washing: washing the first slurry with tap water; S7, beating: putting the washed first slurry into a beating machine for beating, and then putting it into a fine pulping machine for fine beating to obtain a second slurry; S8, bleaching treatment: rinsing the second pulp three times to obtain a fifth pulp; S9, acid treatment: washing the fifth slurry with water to remove sodium chloride, adding hydrochloric acid to acidify, washing to neutrality, adding sodium thiosulfate to remove residual chlorine, and obtaining a sixth slurry; S10, rolling and drying: driving out water from the sixth slurry, and drying to obtain a finished refined cotton; S11. Testing: Use relevant testing instruments to test the pH value and color of refined cotton.

[0007] Furthermore, the proportions of the sodium hydroxide solution, copper sulfate, cyclic ketone compound, stabilizer, sulfur trioxide and hydrogen peroxide are 1.5-2.5%, 0.2-0.35%, 0.1-0.25%, 0.3-0.6%, 0.2-0.5% and 25-35% respectively.

[0008] Furthermore, the cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone in a ratio of 1:0.6:0.8.

[0009] Furthermore, in S4, in the impregnation tank, the height of the impregnation liquid needs to be 10 cm higher than the cotton linters.

[0010] Furthermore, the cooling method in S5 is to set a cooling pipe in the steam bulb, circulate a cold medium in the cooling pipe, and reduce the temperature to 45-50°C.

[0011] Furthermore, the specific methods of the two stages in S5 are: a. Put the soaked cotton linters into a steaming ball, raise the temperature of the steaming ball to 100-120°C, and steam for 60-75 minutes at a pressure of 0.1-0.2MPa; b. Raise the temperature of the steam bulb to 130-140°C and maintain for 45-50 minutes at a pressure of 0.2-0.3 MPa.

[0012] Furthermore, in S6, the washing time is 60-75 minutes, and the temperature is raised to 45-50° C. and kept warm.

[0013] Furthermore, in the beating in S7, the beating time of the first slurry in the beating machine is 60-70 minutes, and the refining time of the first slurry in the refining machine after beating is 35-45 minutes.

[0014] Furthermore, the specific method of the three rinses of the bleaching treatment in S8 is: a. Put the second slurry into a bleaching tank, add H2SO4 to neutralize it, add H2O2 bleaching liquid to bleach, control the temperature at 45-50°C, add 3-5g of stabilizer per liter of bleaching liquid, bleach for 60-80min at a pH value of 7-10, and then rinse to obtain a third slurry; b. Add 2-3% of the solution to the bleaching tank for the second time. bleaching liquid, the ratio of the third slurry to the bleaching liquid is 1:10-15, the temperature is 45-50°C, 1-2g of stabilizer is added to each liter of bleaching liquid, bleaching for 30-50min, and a fourth slurry is obtained; c. Finally, add 2-3% of Bleaching liquid, the ratio of the fourth slurry to the bleaching liquid is 1:10-15, bleaching for 30-50 minutes, and the fifth slurry is obtained.

[0015] Furthermore, in S9, the acidification conditions are: pH value is 2-3, and the acidification time is 20-40 minutes.

[0016] In the above technical scheme, the present invention provides a method for producing special refined cotton with high uniform polymerization degree. By setting up a bleaching process, the bleaching liquid is added to the bleaching tank three times, and the temperature of the bleaching tank is quickly adjusted to the set temperature after each addition of the bleaching liquid, so as to ensure that the temperature of the bleaching tank does not change greatly, thereby avoiding the problem of affecting the bleaching effect due to large temperature changes; By setting the cooking process, the cooking process is divided into two heating cookings, which avoids the difficulty in controlling the depolymerization caused by one cooking, and can effectively control the depolymerization so that the degree of polymerization can reach the required degree of polymerization; Through the setting of the beating process, the beating process is divided into beating and refining. The pulp can be refined after beating, making the pulp more delicate and uniform, and thus the produced refined cotton can be more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0018] Figure 1 A schematic diagram of the process structure of an embodiment of a method for producing special refined cotton with high uniform polymerization degree of the present invention. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0020] like Figure 1 As shown, a method for producing special refined cotton with high uniform polymerization degree provided by the embodiment of the present invention comprises the following steps: S1. Material selection and preparation: Select cotton linters with a fiber length of 10-12mm and a maturity of more than 80% as refined cotton raw materials; S2. Opening and separation of impurities: Put the cotton linters into the cotton opener to loosen them, and then put them into the impurity remover to separate the sand, stone, cotton shell, hair and other impurities mixed in the cotton linters from the cotton linters; S3, preparing a cooking liquid: mixing a certain ratio of sodium hydroxide solution, copper sulfate, a cyclic ketone compound, a stabilizer, sulfur trioxide and hydrogen peroxide to obtain a cooking liquid; S4, impregnation: put the cotton linters into the cooking liquid for immersion, and the height of the impregnation liquid must be 10 cm higher than the cotton linters; S5. Steaming: Pour the soaked cotton linters and the cooking liquid into a steaming ball and steam them in two stages. The specific method of the two-stage steaming is as follows: a. Put the soaked cotton linters into a steaming ball, raise the temperature of the steaming ball to 100-120°C, and steam for 60-75 minutes at a pressure of 0.1-0.2MPa; b. Raise the temperature of the steam bulb to 130-140°C and maintain for 45-50 minutes at a pressure of 0.2-0.3 MPa; Then, the temperature is cooled down by setting a cooling tube in the steaming ball, circulating a cold medium in the cooling tube, and reducing the temperature to 45-50° C. to obtain the first slurry. The two-stage heating and cooking can effectively control the polymerization reduction so that the degree of polymerization can reach the required degree of polymerization; S6, washing: washing the first slurry with tap water for 60-75 min, heating the temperature to 45-50° C. and keeping the temperature; S7, beating: the first pulp after washing is put into a beating machine for beating, and then put into a fine pulping machine for fine beating to obtain a second pulp, the beating time of the first pulp in the beating machine is 60-70 minutes, and the refining time of the first pulp in the refiner after beating is 35-45 minutes, so as to refine the pulp and make the refined cotton produced more uniform; S8, bleaching treatment: rinsing the second pulp three times to obtain a fifth pulp, The specific method of three rinses for bleaching treatment is: a. Put the second slurry into a bleaching tank, add H2SO4 to neutralize it, add H2O2 bleaching liquid to bleach, control the temperature at 45-50°C, add 3-5g of stabilizer per liter of bleaching liquid, bleach for 60-80min at a pH value of 7-10, and then rinse to obtain a third slurry; b. Add 2-3% of the solution to the bleaching tank for the second time. bleaching liquid, the ratio of the third slurry to the bleaching liquid is 1:10-15, the temperature is 45-50°C, 1-2g of stabilizer is added to each liter of bleaching liquid, bleaching for 30-50min, and a fourth slurry is obtained; c. Finally, add 2-3% of Bleaching liquid, the ratio of the fourth slurry to the bleaching liquid is 1:10-15, bleaching for 30-50 minutes, and the fifth slurry is obtained. The bleaching liquid can be added in batches, and the temperature of the bleaching tank can be quickly adjusted to the set temperature after each addition of the bleaching liquid, thereby ensuring that the temperature of the bleaching tank does not change greatly, thereby avoiding the problem of affecting the bleaching effect due to large temperature changes, and making the bleaching effect better; S9, acid treatment: washing the fifth slurry with water to remove sodium chloride, adding hydrochloric acid to acidify, the acidification conditions are: pH value is 2-3, acidification for 20-40 minutes, washing to neutrality, adding sodium thiosulfate to remove residual chlorine, and obtaining a sixth slurry; S10, rolling and drying: driving out water from the sixth slurry, and drying to obtain a finished refined cotton; S11. Testing: Use relevant testing instruments to test the pH value and color of refined cotton.

[0021] In one embodiment provided by the present invention, the proportions of sodium hydroxide solution, copper sulfate, cyclic ketone compound, stabilizer, sulfur trioxide and hydrogen peroxide are 1.5-2.5%, 0.2-0.35%, 0.1-0.25%, 0.3-0.6%, 0.2-0.5% and 25-35%, respectively.

[0022] In another embodiment provided by the present invention, the cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone in a ratio of 1:0.6:0.8.

[0023] Embodiment 1 A method for producing special refined cotton with high uniform polymerization degree comprises the following steps: S1. Material selection and preparation: Select cotton linters with a fiber length of 11 mm and a maturity of more than 80% as refined cotton raw materials; S2. Opening and separation of impurities: Put the cotton linters into the cotton opener to loosen them, and then put them into the impurity remover to separate the sand, stone, cotton shell, hair and other impurities mixed in the cotton linters from the cotton linters; S3, preparing cooking liquid: mixing a certain ratio of sodium hydroxide solution, copper sulfate, cyclic ketone compound, stabilizer, sulfur trioxide and hydrogen peroxide to obtain a cooking liquid, wherein the proportions of sodium hydroxide solution, copper sulfate, cyclic ketone compound, stabilizer, sulfur trioxide and hydrogen peroxide are 1%, 0.3%, 0.2%, 0.4%, 0.3% and 30% respectively, and the cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone in a ratio of 1:0.6:0.8; S4, impregnation: put the cotton linters into the cooking liquid for immersion, and the height of the impregnation liquid must be 10 cm higher than the cotton linters; S5. Steaming: Pour the soaked cotton linters and the cooking liquid into a steaming ball and steam them in two stages. The specific method of the two-stage steaming is as follows: a. Put the soaked cotton linters into a steaming bulb, raise the temperature of the steaming bulb to 110°C, and steam for 70 minutes at a pressure of 0.1 MPa; b. Raise the temperature of the steam bulb to 135°C and maintain for 48 min at a pressure of 0.2 MPa; Then, the temperature is cooled down by setting a cooling tube in the steaming ball, circulating a cold medium in the cooling tube, and reducing the temperature to 47°C to obtain the first slurry. The two-stage heating and cooking can effectively control the polymerization reduction so that the degree of polymerization can reach the required degree of polymerization; S6, washing: washing the first slurry with tap water for 72 minutes, heating the temperature to 45°C and keeping it warm; S7, beating: the first pulp after washing is put into a beating machine for beating, and then put into a fine pulping machine for fine beating to obtain a second pulp, the beating time of the first pulp in the beating machine is 65 minutes, and the refining time of the first pulp in the fine pulping machine after beating is 38 minutes, so as to refine the pulp and make the produced refined cotton more uniform; S8, bleaching treatment: rinsing the second pulp three times to obtain a fifth pulp, The specific method of three rinses for bleaching treatment is: a. Put the second slurry into a bleaching tank, add H2SO4 to neutralize it, add H2O2 bleaching liquid to bleach, control the temperature at 50°C, add 3g of stabilizer per liter of bleaching liquid, bleach for 65min at a pH value of 7, and then rinse to obtain a third slurry; b. Add 2% of the solution to the bleaching tank for the second time. bleaching liquid, the ratio of the third slurry to the bleaching liquid is 1:11, the temperature is 49°C, 1 g of stabilizer is added to each liter of bleaching liquid, and bleaching is performed for 35 minutes to obtain a fourth slurry; c. Finally, add 2% of Bleaching liquid, the ratio of the fourth slurry to the bleaching liquid is 1:12, bleaching for 35 minutes, and the fifth slurry is obtained. The bleaching liquid can be added in batches, and the temperature of the bleaching tank can be quickly adjusted to the set temperature after each addition of the bleaching liquid, thereby ensuring that the temperature of the bleaching tank does not change greatly, thereby avoiding the problem of affecting the bleaching effect due to large temperature changes, and making the bleaching effect better; S9, acid treatment: washing the fifth slurry with water to remove sodium chloride, adding hydrochloric acid to acidify, the acidification conditions are: pH value is 2, acidification for 25 minutes, washing to neutrality, adding sodium thiosulfate to remove residual chlorine, to obtain a sixth slurry; S10, rolling and drying: driving out water from the sixth slurry, and drying to obtain a finished refined cotton; S11. Testing: Use relevant testing instruments to test the pH value and color of refined cotton.

[0024] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for producing special refined cotton with high uniform polymerization degree, characterized in that: The following steps are involved: S1. Material selection and preparation: Select cotton linters with a fiber length of 10-12mm and a maturity of more than 80% as refined cotton raw materials; S2. Opening and separation of impurities: Put the cotton linters into the cotton opener to loosen them, and then put them into the impurity remover to separate the sand, stone, cotton shell, hair and other impurities mixed in the cotton linters from the cotton linters; S3, preparing a cooking liquid: mixing a certain ratio of sodium hydroxide solution, copper sulfate, a cyclic ketone compound, a stabilizer, sulfur trioxide and hydrogen peroxide to obtain a cooking liquid; S4, soaking: soaking the cotton linters in the cooking liquid; S5, cooking: pouring the soaked cotton linters and the cooking liquid into a steaming ball for cooking in two stages, and then cooling to obtain a first slurry; S6, washing: washing the first slurry with tap water; S7, beating: putting the washed first slurry into a beating machine for beating, and then putting it into a fine pulping machine for fine beating to obtain a second slurry; S8, bleaching treatment: rinsing the second pulp three times to obtain a fifth pulp; S9, acid treatment: washing the fifth slurry with water to remove sodium chloride, adding hydrochloric acid to acidify, washing to neutrality, adding sodium thiosulfate to remove residual chlorine, and obtaining a sixth slurry; S10, rolling and drying: driving out water from the sixth slurry, and drying to obtain a finished refined cotton; S11. Testing: Use relevant testing instruments to test the pH value and color of refined cotton.

2. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: The sodium hydroxide solution, copper sulfate, cyclic ketone compound, stabilizer, sulfur trioxide and hydrogen peroxide account for 1.5-2.5%, 0.2-0.35%, 0.1-0.25%, 0.3-0.6%, 0.2-0.5% and 25-35% respectively.

3. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: The cyclic ketone compound is prepared by mixing naphthoquinone, anthraquinone and anthrone in a ratio of 1:0.6:0.

8.

4. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: In S4, in the immersion tank, the height of the immersion liquid needs to be 10 cm higher than the cotton linters.

5. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: The method of cooling in S5 is to set a cooling pipe in the steam bulb, circulate a cold medium in the cooling pipe, and reduce the temperature to 45-50°C.

6. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: The specific methods of the two stages in S5 are: a. Put the soaked cotton linters into a steaming ball, raise the temperature of the steaming ball to 100-120°C, and steam for 60-75 minutes at a pressure of 0.1-0.2MPa; b. Raise the temperature of the steam bulb to 130-140°C and maintain for 45-50 minutes at a pressure of 0.2-0.3 MPa.

7. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: In S6, the washing time is 60-75 minutes, and the temperature is raised to 45-50° C. and kept warm.

8. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: In the beating in S7, the beating time of the first slurry in the beating machine is 60-70 minutes, and the refining time of the first slurry in the refining machine after beating is 35-45 minutes.

9. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: The specific method of the three rinses of the bleaching treatment in S8 is: a. Put the second slurry into a bleaching tank, add H2SO4 to neutralize it, add H2O2 bleaching liquid to bleach, control the temperature at 45-50°C, add 3-5g of stabilizer per liter of bleaching liquid, bleach for 60-80min at a pH value of 7-10, and then rinse to obtain a third slurry; b. Add 2-3% of the solution to the bleaching tank for the second time. bleaching liquid, the ratio of the third slurry to the bleaching liquid is 1:10-15, the temperature is 45-50°C, 1-2g of stabilizer is added to each liter of bleaching liquid, bleaching for 30-50min, and a fourth slurry is obtained; c. Finally, add 2-3% of Bleaching liquid, the ratio of the fourth slurry to the bleaching liquid is 1:10-15, bleaching for 30-50 minutes, and obtaining the fifth slurry.

10. The method for producing special refined cotton with high uniform polymerization degree according to claim 1, characterized in that: In S9, the acidification conditions are: pH value is 2-3, and the acidification time is 20-40 minutes.

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