Weak-damage high-whiteness cellulosic fiber pretreatment process

Abstract

The invention provides a weak-damage high-whiteness cellulose fiber pretreatment process, and relates to the technical field of textile printing and dyeing. The weak-damage high-whiteness cellulose fiber pretreatment process comprises the steps of pretreatment, enzyme treatment, bleaching treatment, weak alkali treatment, neutralization treatment, water washing treatment and softening treatment. Through reasonable combination of the steps, mild treatment of the cellulosic fibers is realized, the damage degree of the cellulosic fibers is greatly reduced, and the whiteness of the treated fibers is greatly improved compared with that of the fibers treated by an original treatment process; and secondly, through a weak-damage high-whiteness cellulose fiber pretreatment process, lignin in the fibers is effectively removed, meanwhile, damage to physical and mechanical properties of the cellulose fibers is reduced, and the whiteness and glossiness of the fibers are improved.

Description

Technical Field

[0001] The invention relates to the technical field of textile printing and dyeing, in particular to a pre-treatment process for cellulose fibers with low damage and high whiteness. Background Art

[0002] The presence of various impurities in cellulose fibers will affect the quality of cellulose. Among them, lignin is the main impurity in cellulose fibers. Fibers with less lignin content have good luster, are soft and elastic, have uniform dyeing and good spinnability. If the fiber contains more lignin, the luster, softness, elasticity, spinnability and colorability are poor. The main purpose of the cellulose fiber pretreatment process is to remove lignin from the fiber.

[0003] At present, the methods for removing lignin from raw hemp mainly include traditional halogenation method, traditional oxidation method, traditional alkali method, etc.

[0004] The halogenation method is to pass chlorine gas into dry cellulose fibers, or immerse dry fibers in a chlorine aqueous solution and a carbon tetrachloride solution. When water is present, chlorine gas reacts with water to generate hydrochloric acid and hypochlorous acid. Hydrochloric acid has a certain hydrolysis effect on cellulose, and hypochlorous acid has strong oxidizing properties, which damages cellulose.

[0005] The traditional oxidation method is to use strong oxidants to react with lignin to remove lignin. However, the reaction conditions of the traditional oxidation method are extremely strict. Once the conditions exceed the range, the cellulose will be destroyed and the fiber will deteriorate. At the same time, several treatment methods will make the fiber yellow and poor in whiteness due to the oxidation-reduction effect.

[0006] In summary, the traditional pretreatment method of cellulose fiber is to use alkali scouring or strong alkali oxidation, which is to treat the fiber strongly under high temperature and pH conditions. After treatment, there will be phenomena such as unclean treatment, fiber damage after treatment, and fiber structural destruction. Therefore, it is extremely important for the cotton and linen textile industry to study a production process that can effectively remove lignin from cellulose fibers without affecting the physical and mechanical properties of cellulose fibers and improving whiteness. Summary of the invention

[0007] 1. Technical issues to be solved

[0008] In view of the deficiencies of the prior art, the present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, which solves the problems raised by the above-mentioned background technology.

[0009] (II) Technical solution

[0010] To achieve the above objectives, the present invention is implemented by the following technical scheme: A cellulose fiber pretreatment process with low damage and high whiteness comprises the following steps:

[0011] Step 1: Preprocessing:

[0012] Add the cellulose raw material into the pretreatment solution and treat at 40-50°C for 20-30 minutes;

[0013] Step 2: Enzyme treatment:

[0014] The pretreated cellulose raw material is added to the enzyme treatment solution and treated at 50-60°C for 30-60 minutes;

[0015] Step 3: Bleaching:

[0016] The enzyme-treated cellulose raw material is added to the bleaching solution and treated at 70-80°C for 40-60 minutes;

[0017] Step 4: Weak alkali treatment:

[0018] The bleached cellulose raw material is added into a weak alkaline treatment solution, and then an oxidant and a slow-release additive are added, and the treatment is carried out at 80-100°C for 50-100 minutes;

[0019] Step 5: Neutralization treatment:

[0020] The cellulose raw material treated with weak alkali is added into the acidic treatment liquid for neutralization, and treated at 40-50°C for 20-30 minutes;

[0021] Step 6: Washing:

[0022] The neutralized cellulose raw material is added into clean water and fully washed until the pH value of the washing liquid is 7-8;

[0023] Step 7: Softening:

[0024] The washed cellulose raw material is added into a softener solution and treated at 40-50°C for 20-30 minutes to obtain cellulose fibers.

[0025] Preferably, in step one, the pretreatment liquid comprises the following components: 2-5 g / L of nonionic surfactant, 1-3 g / L of penetrant, and 0.5-1.5 g / L of chelating agent; specifically, the nonionic surfactant is alkylphenol polyoxyethylene ether, the penetrant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium ethylenediaminetetraacetic acid.

[0026] Preferably, in step 2, the enzyme treatment solution comprises the following components: 1-3 g / L cellulase, 0.5-1.5 g / L pectinase, and 2-5 g / L buffer; specifically, the cellulase is β-1,4-endoglucanase, the pectinase is polygalacturonase, and the buffer is phosphate buffer.

[0027] Preferably, in step three, the bleaching solution comprises the following components: 3-6 g / L hydrogen peroxide and 2-4 g / L stabilizer; specifically, the stabilizer is sodium silicate.

[0028] Preferably, in step 4, the weak alkaline treatment solution is composed of a strong alkaline substance and a weak alkaline substance, wherein the strong alkaline substance is 0.5-1 g / L and the weak alkaline substance is 1-2 g / L.

[0029] Preferably, the strong alkaline substance is sodium hydroxide, the weak alkaline substance is sodium carbonate, the oxidant is sodium persulfate, and the sustained-release aid is sodium polyacrylate.

[0030] Preferably, in step five, the acidic treatment solution comprises the following components: 0.5-1 g / L hydrochloric acid and 1-3 g / L buffer; specifically, the hydrochloric acid is industrial grade hydrochloric acid and the buffer is sodium acetate.

[0031] Preferably, in step seven, the softener is 1-3 g / L of polysiloxane.

[0032] (III) Beneficial effects

[0033] The present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, which has the following beneficial effects:

[0034] 1. The present invention effectively removes lignin in the fiber through a weakly damaged high-whiteness cellulose fiber pretreatment process, while reducing damage to the physical and mechanical properties of the cellulose fiber and improving the whiteness and glossiness of the fiber.

[0035] 2. The present invention achieves gentle treatment of cellulose fibers through a reasonable combination of pretreatment, enzyme treatment, bleaching treatment, weak alkali treatment, neutralization treatment, water washing treatment and softening treatment, greatly reducing the degree of damage to cellulose fibers, and the whiteness of the treated fibers is greatly improved compared with the original treatment process.

[0036] In summary, the present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, which can not only effectively remove lignin and other impurities in the fiber, but also cause little damage to the fiber during the treatment process, and can significantly improve the whiteness and quality of the fiber. It has important practical value and broad market application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Embodiment 1:

[0040] like Figure 1 As shown, the embodiment of the present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, comprising the following steps:

[0041] Step 1: Preprocessing:

[0042] The cellulose raw material is added into the pretreatment solution and treated at 40°C for 20 minutes; wherein the pretreatment solution comprises the following components: 2 g / L of nonionic surfactant, 1.0 g / L of penetrant, and 0.5 g / L of chelating agent; specifically, the nonionic surfactant is alkylphenol polyoxyethylene ether, the penetrant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium ethylenediaminetetraacetate;

[0043] Step 2: Enzyme treatment:

[0044] The pretreated cellulose raw material is added to an enzyme treatment solution and treated at 50°C for 30 minutes; wherein the enzyme treatment solution comprises the following components: 1.0 g / L cellulase, 0.5 g / L pectinase, and 2.0 g / L buffer; specifically, the cellulase is β-1,4-endoglucanase, the pectinase is polygalacturonase, and the buffer is phosphate buffer;

[0045] Step 3: Bleaching:

[0046] The cellulose raw material after enzyme treatment is added into a bleaching solution and treated at 70°C for 40 minutes; wherein the bleaching solution comprises the following components: 3.0 g / L hydrogen peroxide and 2.0 g / L stabilizer; specifically, the stabilizer is sodium silicate;

[0047] Step 4: Weak alkali treatment:

[0048] The cellulose raw material after bleaching is added into a weak alkaline treatment solution, wherein the weak alkaline treatment solution is composed of a strong alkaline substance and a weak alkaline substance, the strong alkaline substance is 0.5 g / L, the weak alkaline substance is 1.0 g / L, and then an oxidant and a slow-release aid are added, and the treatment is carried out at 80° C. for 50 minutes; specifically, the strong alkaline substance is sodium hydroxide, the weak alkaline substance is sodium carbonate, the oxidant is sodium persulfate, and the slow-release aid is sodium polyacrylate;

[0049] Step 5: Neutralization treatment:

[0050] The cellulose raw material treated with weak alkali is added to an acidic treatment solution for neutralization, and treated at 40° C. for 20 minutes; wherein the acidic treatment solution comprises the following components: 0.5 g / L hydrochloric acid and 1.0 g / L buffer; specifically, the hydrochloric acid is industrial grade hydrochloric acid, and the buffer is sodium acetate;

[0051] Step 6: Washing:

[0052] The neutralized cellulose raw material is added into clean water and fully washed until the pH value of the washing liquid reaches 7;

[0053] Step 7: Softening:

[0054] The washed cellulose raw material is added into a softener solution and treated at 40° C. for 20 minutes. The softener is 1.0 g / L polysiloxane, thereby obtaining cellulose fibers.

[0055] Embodiment 2:

[0056] like Figure 1 As shown, the embodiment of the present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, comprising the following steps:

[0057] Step 1: Preprocessing:

[0058] The cellulose raw material is added into the pretreatment solution and treated at 45°C for 25 minutes; wherein the pretreatment solution comprises the following components: 4.0 g / L of nonionic surfactant, 2.0 g / L of penetrant, and 1.0 g / L of chelating agent; specifically, the nonionic surfactant is alkylphenol polyoxyethylene ether, the penetrant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium ethylenediaminetetraacetate;

[0059] Step 2: Enzyme treatment:

[0060] The pretreated cellulose raw material is added to an enzyme treatment solution and treated at 55°C for 45 minutes; wherein the enzyme treatment solution comprises the following components: 2.0 g / L cellulase, 1.0 g / L pectinase, and 4.0 g / L buffer; specifically, the cellulase is β-1,4-endoglucanase, the pectinase is polygalacturonase, and the buffer is phosphate buffer;

[0061] Step 3: Bleaching:

[0062] The cellulose raw material after enzyme treatment is added into a bleaching solution and treated at 75°C for 50 minutes; wherein the bleaching solution comprises the following components: 5.0 g / L hydrogen peroxide and 3.0 g / L stabilizer; specifically, the stabilizer is sodium silicate;

[0063] Step 4: Weak alkali treatment:

[0064] The cellulose raw material after bleaching is added into a weak alkaline treatment solution, wherein the weak alkaline treatment solution is composed of a strong alkaline substance and a weak alkaline substance, the strong alkaline substance is 1.0 g / L, the weak alkaline substance is 1.5 g / L, and then an oxidant and a slow-release aid are added, and the treatment is carried out at 90° C. for 80 minutes; specifically, the strong alkaline substance is sodium hydroxide, the weak alkaline substance is sodium carbonate, the oxidant is sodium persulfate, and the slow-release aid is sodium polyacrylate;

[0065] Step 5: Neutralization treatment:

[0066] The cellulose raw material treated with weak alkali is added to an acidic treatment solution for neutralization, and treated at 45° C. for 25 minutes; wherein the acidic treatment solution comprises the following components: 1.0 g / L hydrochloric acid and 2.0 g / L buffer; specifically, the hydrochloric acid is industrial grade hydrochloric acid, and the buffer is sodium acetate;

[0067] Step 6: Washing:

[0068] The neutralized cellulose raw material is added into clean water and fully washed until the pH value of the washing liquid reaches 7.5;

[0069] Step 7: Softening:

[0070] The washed cellulose raw material is added into a softener solution, treated at 45°C for 25 minutes, and the softener is 2.0 g / L of polysiloxane, to obtain cellulose fibers.

[0071] Embodiment three:

[0072] like Figure 1 As shown, the embodiment of the present invention provides a cellulose fiber pretreatment process with low damage and high whiteness, comprising the following steps:

[0073] Step 1: Preprocessing:

[0074] The cellulose raw material is added into the pretreatment solution and treated at 50°C for 30 minutes; wherein the pretreatment solution comprises the following components: 5.0 g / L of nonionic surfactant, 3.0 g / L of penetrant, and 1.5 g / L of chelating agent; specifically, the nonionic surfactant is alkylphenol polyoxyethylene ether, the penetrant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium ethylenediaminetetraacetate;

[0075] Step 2: Enzyme treatment:

[0076] The pretreated cellulose raw material is added to an enzyme treatment solution and treated at 60°C for 60 minutes; wherein the enzyme treatment solution comprises the following components: 3.0 g / L cellulase, 1.5 g / L pectinase, and 5.0 g / L buffer; specifically, the cellulase is β-1,4-endoglucanase, the pectinase is polygalacturonase, and the buffer is phosphate buffer;

[0077] Step 3: Bleaching:

[0078] The cellulose raw material after enzyme treatment is added into a bleaching solution and treated at 80° C. for 60 minutes; wherein the bleaching solution comprises the following components: 6.0 g / L hydrogen peroxide and 4.0 g / L stabilizer; specifically, the stabilizer is sodium silicate;

[0079] Step 4: Weak alkali treatment:

[0080] The cellulose raw material after bleaching is added into a weak alkaline treatment solution, wherein the weak alkaline treatment solution is composed of a strong alkaline substance and a weak alkaline substance, the strong alkaline substance is 1.0 g / L, the weak alkaline substance is 2.0 g / L, and then an oxidant and a slow-release aid are added, and the treatment is carried out at 100° C. for 100 minutes; specifically, the strong alkaline substance is sodium hydroxide, the weak alkaline substance is sodium carbonate, the oxidant is sodium persulfate, and the slow-release aid is sodium polyacrylate;

[0081] Step 5: Neutralization treatment:

[0082] The cellulose raw material treated with weak alkali is added to an acidic treatment solution for neutralization, and treated at 50° C. for 30 minutes; wherein the acidic treatment solution comprises the following components: 1.0 g / L hydrochloric acid and 3.0 g / L buffer; specifically, the hydrochloric acid is industrial grade hydrochloric acid, and the buffer is sodium acetate;

[0083] Step 6: Washing:

[0084] The neutralized cellulose raw material is added into clean water and fully washed until the pH value of the washing liquid reaches 8;

[0085] Step 7: Softening:

[0086] The washed cellulose raw material is added into a softener solution and treated at 50° C. for 30 minutes. The softener is 3.0 g / L of polysiloxane to obtain cellulose fibers.

[0087] Comparative Example 1:

[0088] The traditional cellulose fiber pretreatment process is adopted, that is, scouring is carried out under high temperature (95-100℃) and strong alkali (sodium hydroxide concentration is 8-10g / L) conditions, and then bleaching treatment is carried out (hydrogen peroxide concentration is 5-8g / L, sodium hydroxide concentration is 2-3g / L, temperature is 90-95℃, and time is 60-90min).

[0089] Comparative Example 2:

[0090] The difference between this comparative example and the first embodiment is that step 2 is omitted, and the remaining steps are the same as those of the first embodiment.

[0091] Comparative Example 3:

[0092] The difference between this comparative example and the first embodiment is that steps four and five are omitted, and the remaining steps are the same as those of the first embodiment.

[0093] Experimental example:

[0094] The cellulose fibers treated in the above embodiments and comparative examples were subjected to performance tests, and the test results are shown in the following table:

[0095] Example Whiteness(%) Breaking strength (cN / tex) Softness Embodiment 1 85.5 25.6 better Embodiment 2 86.2 26.3 better Embodiment 3 87.1 27.1 better Comparative Example 1 67.7 19.7 Poor Comparative Example 2 72.2 20.4 generally Comparative Example 3 73.8 20.9 generally

[0096] In summary, the whiteness of the cellulose fibers of Examples 1 to 3 is higher than 85%, which is significantly higher than 67.7% of Comparative Example 1. In terms of strength, the cellulose fibers of Examples 1 to 3 are all above 25 cN / tex, while Comparative Example 1 is only 19.7 cN / tex. In terms of softness, the softness of the cellulose fibers of Examples 1 to 3 is significantly better than that of Comparative Example 1.

[0097] The cellulose fibers of Examples 1 to 3 were less damaged during the treatment process, and the physical properties of the fibers were effectively protected. However, in Comparative Example 1, the fibers were more damaged due to the high temperature and strong alkali treatment, and the strength and softness were reduced.

[0098] In addition, although the processing steps of Comparative Examples 2 and 3 were reduced to a certain extent, their whiteness, strength and softness were lower than those of Examples 1 to 3, indicating that omitting certain key steps would have a negative impact on the final properties of the cellulose fiber.

[0099] In summary, the weakly damaged high-whiteness cellulose fiber pretreatment process provided by the embodiment of the present invention can effectively improve the whiteness, strength and softness of the cellulose fibers while reducing damage to the fibers, and has high practical value and market application prospects.

[0100] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cellulose fiber pretreatment process with low damage and high whiteness, characterized by: The following steps are involved: Step 1: Preprocessing: Add the cellulose raw material into the pretreatment solution and treat at 40-50°C for 20-30 minutes; Step 2: Enzyme treatment: The pretreated cellulose raw material is added to the enzyme treatment solution and treated at 50-60°C for 30-60 minutes; Step 3: Bleaching: The enzyme-treated cellulose raw material is added to the bleaching solution and treated at 70-80°C for 40-60 minutes; Step 4: Weak alkali treatment: The bleached cellulose raw material is added into a weak alkaline treatment solution, and then an oxidant and a slow-release additive are added, and the treatment is carried out at 80-100°C for 50-100 minutes; Step 5: Neutralization treatment: The cellulose raw material treated with weak alkali is added into the acidic treatment liquid for neutralization, and treated at 40-50°C for 20-30 minutes; Step 6: Washing: The neutralized cellulose raw material is added into clean water and fully washed until the pH value of the washing liquid is 7-8; Step 7: Softening: The washed cellulose raw material is added into a softener solution and treated at 40-50°C for 20-30 minutes to obtain cellulose fibers.

2. The pretreatment process of cellulose fiber with low damage and high whiteness according to claim 1, characterized in that: In step one, the pretreatment liquid includes the following components: 2-5 g / L of nonionic surfactant, 1-3 g / L of penetrant, and 0.5-1.5 g / L of chelating agent; specifically, the nonionic surfactant is alkylphenol polyoxyethylene ether, the penetrant is fatty alcohol polyoxyethylene ether, and the chelating agent is disodium ethylenediaminetetraacetic acid.

3. The pretreatment process of cellulose fiber with low damage and high whiteness according to claim 1, characterized in that: In step 2, the enzyme treatment solution includes the following components: 1-3 g / L cellulase, 0.5-1.5 g / L pectinase, and 2-5 g / L buffer; specifically, the cellulase is β-1,4-endoglucanase, the pectinase is polygalacturonase, and the buffer is phosphate buffer.

4. The pretreatment process of the cellulose fiber with low damage and high whiteness according to claim 1, characterized in that: In step three, the bleaching solution includes the following components: 3-6 g / L of hydrogen peroxide and 2-4 g / L of a stabilizer; specifically, the stabilizer is sodium silicate.

5. The process for pre-treating cellulose fibers with low damage and high whiteness according to claim 1, characterized in that: In step 4, the weak alkaline treatment solution is composed of a strong alkaline substance and a weak alkaline substance, wherein the strong alkaline substance is 0.5-1 g / L and the weak alkaline substance is 1-2 g / L.

6. A pretreatment process for cellulose fibers with low damage and high whiteness according to claim 5, characterized in that: The strong alkaline substance is sodium hydroxide, the weak alkaline substance is sodium carbonate, the oxidant is sodium persulfate, and the sustained-release aid is sodium polyacrylate.

7. The pretreatment process of cellulose fiber with low damage and high whiteness according to claim 1, characterized in that: In step 5, the acidic treatment solution includes the following components: 0.5-1 g / L hydrochloric acid, 1-3 g / L buffer; Specifically, the hydrochloric acid is industrial grade hydrochloric acid, and the buffer is sodium acetate.

8. The pretreatment process of cellulose fiber with low damage and high whiteness according to claim 1, characterized in that: In step seven, the softener is 1-3 g / L of polysiloxane.

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