Green energy-saving low-surface-activity degreasing cotton pretreatment process

Abstract

The invention discloses a green energy-saving low-surface-activity degreasing cotton pretreatment process, and belongs to the technical field of cotton fabric pretreatment. The microbubble water is introduced in the degreasing, oxygen bleaching and water washing links for effect enhancement, and the problems that in the degreasing, bleaching and water washing processes of degreasing cotton, the pretreatment agent dosage is large, water resources are wasted, the cleaning effect is poor, and the process is complex are effectively solved. The water consumption in the pretreatment process is only 40-50% of that in the traditional process, the pretreatment auxiliaries are reduced by 40%, the time is saved by more than 50%, the degreasing, oxygen bleaching and washing efficiency is greatly improved, the pretreatment effect of the traditional process can still be achieved or even surpassed under the conditions of low water consumption, low energy consumption, low cost and great reduction of pollutant emission, and the method has remarkable environmental protection benefits. And the production efficiency is improved, the production cost is reduced, and remarkable economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the field of cotton fabric pretreatment, and in particular relates to a green, energy-saving and low-surface-activity absorbent cotton pretreatment process. Background Art

[0002] In the traditional pre-treatment process of cotton fabrics, impurities such as cottonseed hull fragments, dust, leaf debris, and grease, protein, and wax attached to cotton must be removed. The commonly used method is to add surfactants, sodium hydroxide, and hydrogen peroxide to perform degreasing oxygen bleaching under high temperature conditions, and then rinse with clean water. However, this traditional method not only consumes a lot of water resources, but also has limited cleaning effect, especially for the removal of impurities and residual chemicals deep inside the cotton fiber. At the same time, traditional processes often have complex process flows and long processing times, resulting in low production efficiency and high production costs. Therefore, it is an urgent need for the textile industry to develop a cotton fabric pre-treatment process that is efficient, water-saving, and can ensure cleaning quality. Summary of the invention

[0003] The present invention aims at the deficiencies of the above-mentioned prior art and provides a green, energy-saving and low-surface-activity pretreatment process for absorbent cotton. The present invention introduces microbubble water in the degreasing oxygen bleaching and water washing process to enhance the effect, thereby effectively solving the problems of water resource waste, poor cleaning effect, complex process, and high sewage treatment cost caused by large amount of pretreatment agent used in the degreasing oxygen bleaching and water washing process.

[0004] The core of the present invention is to utilize the special physical properties of microbubbles to improve the degreasing oxygen bleaching and cleaning efficiency.

[0005] The green, energy-saving and low-surface-activity absorbent cotton pretreatment process of the present invention comprises the following steps:

[0006] Step 1: Degreasing and oxygen bleaching

[0007] The raw cotton after cake pressing is hung into the drum bleaching machine, and pure water rich in microbubbles is passed through. Then a certain amount of pretreatment agent and 2% sodium hydroxide are added. Microbubbles are continued to be passed through and the temperature is raised to 50°C. The time for passing microbubbles is controlled at 8-10 minutes. Then 8% hydrogen peroxide (concentration 27.5%) is added, and the temperature is raised to 90°C at a speed of 2°C / min and then kept warm.

[0008] Step 2: Wash

[0009] 2a. Initial washing: The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, and micro-bubble water is added to wash at room temperature for 20 minutes and then emptied. The number of washing times is determined according to the water quality SS. If the sewage SS after washing is higher than the set value, it needs to be washed again.

[0010] 2b. Neutralization washing: Add microbubble washing water and 5kg citric acid at room temperature, adjust the pH value of the washing water in the drum bleaching machine to 7-8, and drain the washing water after washing for 20 minutes.

[0011] Step 3: Remove from the cylinder

[0012] The neutralized and washed absorbent cotton is removed from the drum bleaching machine for subsequent processes such as centrifugal dehydration and drying.

[0013] In step 1, the microbubble concentration in the degreasing oxygen bleaching section is 10 3 -10 6 / ml, the proportion of microbubbles with a diameter between 10-300μm exceeds 50%, and the time for microbubble introduction is 8-10min. In this process, it is necessary to avoid too high or too low microbubble concentration in the degreasing and oxygen bleaching section. If it is too low, the effect is not obvious. If it is too high, the pressure in the cylinder bleaching machine will be too high after heating. Generally, the control range of the steam pressure in the cylinder is within 0.5MPa. The degreasing liquid and oxygen bleaching liquid containing microbubbles can accelerate the saponification reaction of sodium hydroxide solution with impurities such as oil and fat on the surface of cotton fibers, converting them into water-soluble substances, greatly improving the degreasing and oxygen bleaching efficiency. Under the same conditions, the whiteness, water absorption, drying loss and other indicators of the absorbent cotton treated with the degreasing and oxygen bleaching liquid containing microbubbles are significantly improved.

[0014] In step 1, the degreasing oxygen bleaching holding temperature is set at 90±5°C and the holding time is 60 minutes.

[0015] In step 2, the microbubble concentration in the water washing section is ≥10 4 / ml, the diameter of microbubbles suitable for washing in the washing section is greater than 60% in the range of 1-200μm. Microbubbles are constantly moving and bursting in the washing water, and the local impact force and micro-turbulence generated can attach the microbubbles and penetrate into the gaps and holes of the fibers, adsorb and carry away the residual sodium hydroxide solution and impurity particles, accelerate the neutralization reaction of acid sodium hydroxide, and promptly peel off and take away the salts and other substances generated by the reaction from the surface of the cotton fibers to prevent secondary deposition. Under the same conditions, after washing with water containing microbubbles and washing with pure water, the whiteness, surface activity, sinking time, drying weight loss, soluble matter in water and other indicators of the treated absorbent cotton are significantly improved.

[0016] In step 2, the effluent from the initial washing section has a SS of ≤30 mg / L, and the effluent from the neutralization washing section has a SS of ≤20 mg / L.

[0017] In the present invention, the preparation of microbubble cleaning water is to disperse gas (such as air) in the form of microbubbles evenly in the cleaning water through a microbubble generating device. These microbubbles usually have a diameter between a few microns and several hundred microns, have a large specific surface area, surface energy, impact force and penetration force, and can greatly improve the working efficiency of the degreasing oxygen bleaching and water washing process.

[0018] The beneficial effects of the present invention are embodied in:

[0019] 1. Significant water-saving, energy-saving and time-saving effects. The water used in the pretreatment process of the present invention is only 40-50% of that in the traditional process, the pretreatment additives are reduced by 40%, and the time saving exceeds 50%. The degreasing oxygen bleaching and cleaning efficiency are greatly improved, so that the pretreatment effect of the traditional process can be achieved or even exceeded under the conditions of low dosage, low water consumption, low energy consumption and low cost, and it has significant environmental benefits. It improves production efficiency, reduces production costs, and has significant economic benefits.

[0020] 2. Highly efficient degreasing, oxygen bleaching and cleaning capabilities. Microbubbles can penetrate deep into the cotton fibers, accelerate the internal and external circulation of cotton fibers, bleaching liquid and cleaning water, greatly improve the degreasing and oxygen bleaching efficiency, and the residual sodium hydroxide solution and impurities can be quickly removed from the fiber to the cleaning water during the washing process, thus improving the overall cleanliness and quality of cotton fabrics.

[0021] 3. Simplify the process flow. The cumbersome cleaning steps and repeated flushing steps in the traditional process are reduced, the number of water washing sections is reduced by 50%, the process flow is more concise and clear, easy to operate and control, and the production cost is reduced.

[0022] In summary, the cotton fabric microbubble cleaning process of the present invention has significant advantages in water saving, cleaning effect, process simplification and product quality assurance, and has broad application prospects and market value. DETAILED DESCRIPTION

[0023] The present invention will be specifically described below by way of examples, but the present invention is not limited to the following examples.

[0024] The pre-treatment agent used in the following examples and comparative examples is a commercially available product with the trade name of cotton degreasing agent KA, produced by Hefei Dongfang Meijie Molecular Materials Technology Co., Ltd., which integrates penetration, stabilization, chelating dispersion, emulsification, wax removal, etc.

[0025] Embodiment 1:

[0026] 1. Preparation

[0027] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0028] 2. Degreasing and oxygen bleaching

[0029] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 20 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 110℃ at a rate of 2℃ / min, keep warm at 110±5℃ for 90 minutes, and then drain the degreasing liquid.

[0030] 3. Washing

[0031] (1) Initial washing

[0032] The raw cotton after degreasing and oxygen bleaching remains in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added, and it is first overflow washed for 5 minutes, then washed at room temperature for 30 minutes, emptied and washed again four times.

[0033] (2) Neutralization washing

[0034] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 30 minutes of cleaning.

[0035] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0036] 4. Leaving the cylinder

[0037] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0038] Embodiment 2:

[0039] 1. Preparation

[0040] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0041] 2. Degreasing and oxygen bleaching

[0042] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0043] 3. Washing

[0044] (1) Initial washing

[0045] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0046] (2) Neutralization washing

[0047] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0048] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0049] 4. Leaving the cylinder

[0050] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0051] Embodiment 3:

[0052] 1. Preparation

[0053] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0054] 2. Degreasing and oxygen bleaching

[0055] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 8 kg of pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0056] 3. Washing

[0057] (1) Initial washing

[0058] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0059] (2) Neutralization washing

[0060] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0061] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0062] 4. Leaving the cylinder

[0063] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0064] Embodiment 4:

[0065] 1. Preparation

[0066] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0067] 2. Degreasing and oxygen bleaching

[0068] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0069] 3. Washing

[0070] (1) Initial washing

[0071] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and it is cleaned at room temperature for 20 minutes and then emptied.

[0072] (2) Neutralization washing

[0073] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0074] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0075] 4. Leaving the cylinder

[0076] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0077] Embodiment 5:

[0078] 1. Preparation

[0079] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0080] 2. Degreasing and oxygen bleaching

[0081] Hang the pressed raw cotton into the drum bleaching machine. Pass fresh water, then add 12 kg pre-treatment agent and 2% sodium hydroxide, raise the temperature to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), raise the temperature to 90℃ at a speed of 2℃ / min, keep it at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0082] 3. Washing

[0083] (1) Initial washing

[0084] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0085] (2) Neutralization washing

[0086] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0087] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0088] 4. Leaving the cylinder

[0089] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0090] Embodiment 6:

[0091] 1. Preparation

[0092] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0093] 2. Degreasing and oxygen bleaching

[0094] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water is introduced and the micro-bubble concentration is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 12 kg pretreatment agent and 2% sodium hydroxide, heat to 50℃ and then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a speed of 2℃ / min, keep warm at 90±5℃ for 60min and then drain the degreasing liquid.

[0095] 3. Washing

[0096] (1) Initial washing

[0097] The raw cotton after degreasing and oxygen bleaching remains in the drum bleaching machine, the degreasing and oxygen bleaching liquid is drained, pure water is added and washed at room temperature for 20 minutes, then the liquid is drained and the washing is repeated.

[0098] (2) Neutralization washing

[0099] Add pure water and 5kg citric acid at room temperature to adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0100] 4. Leaving the cylinder

[0101] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0102] Embodiment 7:

[0103] 1. Preparation

[0104] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0105] 2. Degreasing and oxygen bleaching

[0106] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 2 -10 3 / ml, microbubble size 10-300μm greater than 30%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0107] 3. Washing

[0108] (1) Initial washing

[0109] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0110] (2) Neutralization washing

[0111] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0112] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0113] 4. Leaving the cylinder

[0114] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0115] Embodiment 8:

[0116] 1. Preparation

[0117] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0118] 2. Degreasing and oxygen bleaching

[0119] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0120] 3. Washing

[0121] (1) Initial washing

[0122] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0123] (2) Neutralization washing

[0124] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0125] Microbubble concentration in water washing process is controlled to be ≥10 3 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 30%.

[0126] 4. Leaving the cylinder

[0127] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0128] Embodiment 9:

[0129] 1. Preparation

[0130] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0131] 2. Degreasing and oxygen bleaching

[0132] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 40%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0133] 3. Washing

[0134] (1) Initial washing

[0135] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0136] (2) Neutralization washing

[0137] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0138] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 60%.

[0139] 4. Leaving the cylinder

[0140] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0141] Embodiment 10:

[0142] 1. Preparation

[0143] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0144] 2. Degreasing and oxygen bleaching

[0145] The raw cotton after cake pressing is hung into the drum bleaching machine. Fresh water containing microbubbles is introduced, and the concentration of microbubbles is controlled at 10 3 -10 6 / ml, microbubble size 10-300μm greater than 50%; then add 12 kg pretreatment agent and 2% sodium hydroxide, continue to let microbubbles in for 8 minutes, and heat to 50℃, then add 8% hydrogen peroxide (concentration 27.5%), heat to 90℃ at a rate of 2℃ / min, keep warm at 90±5℃ for 60 minutes, and then drain the degreasing liquid.

[0146] 3. Washing

[0147] (1) Initial washing

[0148] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, micro-bubble water is added and washed at room temperature for 20 minutes, then emptied and washed again.

[0149] (2) Neutralization washing

[0150] Add microbubble cleaning water and 5kg citric acid at room temperature, adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 20 minutes of cleaning.

[0151] Microbubble concentration in water washing process is controlled to be ≥10 4 / ml, and the proportion of microbubbles with a size of 1-200μm is more than 50%.

[0152] 4. Leaving the cylinder

[0153] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0154] Comparative Example 1:

[0155] 1. Preparation

[0156] After being cleaned by cleaning equipment, the absorbent cotton is sent to the cake press to be pressed into cakes for later use.

[0157] 2. Degreasing and oxygen bleaching

[0158] The pressed raw cotton is hung into the drum bleaching machine. Fresh water is introduced, and then 20 kg of pre-treatment agent and 2% sodium hydroxide are added to raise the temperature to 50°C, and then 8% hydrogen peroxide (concentration 27.5%) is added, and the temperature is raised to 110°C at a speed of 2°C / min. Keep the temperature at 110±5°C for 90 minutes and then drain the degreasing liquid.

[0159] 3. Washing

[0160] (1) Initial washing

[0161] The raw cotton after degreasing and oxygen bleaching is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, pure water is added to overflow and wash for 5 minutes, then washed at room temperature for 30 minutes, emptied and washed again four times.

[0162] (2) Neutralization washing

[0163] Add pure water and 5kg citric acid at room temperature to adjust the pH value of the cleaning water in the drum bleaching machine to 7-8, and drain the cleaning water after 30 minutes of cleaning.

[0164] 4. Leaving the cylinder

[0165] The neutralized and washed absorbent cotton is removed from the tank for subsequent processes such as centrifugal dehydration and drying.

[0166] The absorbent cotton after drying in the above-mentioned embodiments and comparative examples were sampled and tested. The surface activity and whiteness were in accordance with the standard "Medical Absorbent Gauze" YY0331-2002, and the water absorption, drying weight loss, sinking time and insoluble matter in water were in accordance with the standard "Medical Absorbent Gauze" YY / T 0330-2015. The test results are shown in Table 1 below:

[0167]

[0168] It can be seen from Examples 1-10 that Example 1 is compared with the process conditions of Example 1 of the conventional one-bath process, and microbubble water is used in the water for degreasing oxygen bleaching and washing. The technical indicators such as whiteness, surface activity, water absorption, and sinking time are better than those of Example 1 in all aspects, and the number and duration of water washing and the dosage of the pretreatment agent are larger.

[0169] Example 2 is the best case, which is the best result of comprehensive pretreatment dosage, microbubble water parameter control and stage process evaluation. The technical indicators of the absorbent cotton treated by this process are also better than those of Examples 3-10 and Comparative Example 1, and it is also the best choice in terms of comprehensive cost and effect.

[0170] In Example 3, the pretreatment agent was adjusted, and the other steps were the same as in Example 2. The verification results showed that too little pretreatment agent had a certain influence on the whiteness, water absorption and drying loss of the treated absorbent cotton.

[0171] Example 4 investigated the effect of the number of water washings on the pre-treatment effect in the water washing section. The verification results showed that reducing the number of water washings had a significant impact on the whiteness, surface activity, sinking time, drying loss, and insoluble matter in water of the treated absorbent cotton.

[0172] Example 5 investigated the effects of not using microbubble water in degreasing and oxygen bleaching. The results showed that not using microbubble water in the degreasing and oxygen bleaching process had a significant impact on the whiteness, sinking time, and drying loss of the treated absorbent cotton, among which the whiteness and water absorption did not meet the standards.

[0173] Example 6 investigated the effect of not using microbubble water in the washing process on the treatment effect. The verification results showed that the whiteness, surface activity, sinking time, drying loss and insoluble matter in water of the treated absorbent cotton did not meet the standards.

[0174] Example 7 and Example 9 investigated the effects of microbubble concentration and microbubble size control on the treatment effect in the degreasing oxygen bleaching step. The verification results showed that the whiteness, water absorption and drying loss of the treated absorbent cotton were significantly reduced compared with the optimal example.

[0175] Examples 8 and 10 investigated the effects of microbubble concentration and microbubble size control in the washing process on the treatment effect. The verification results showed that the whiteness, surface activity, sinking time and insoluble matter in water of the treated absorbent cotton were significantly reduced compared to the optimal level.

[0176] The comparison of microbubble parameter control, dosage, degreasing oxygen bleaching temperature and time, water consumption and time consumption is shown in Table 2. It can be seen from Table 2 that compared with the traditional process, the optimal example reduces the dosage of pretreatment chemicals by 40%, saves more than 50% of water, reduces the number of water washing times by half, saves more than 50% of time, and significantly reduces energy consumption. It has significant economic and environmental benefits and has wide application and promotion value.

[0177]

[0178] It can be seen from the embodiments and comparative examples that the absorbent cotton pre-treated by the process of the present invention simplifies the process flow, has significant effects of saving water, energy and time, and has wide application and promotion value.

[0179] The above embodiments are only preferred solutions of the present invention and are not intended to limit the protection scope thereof. Any reasonable replacement or improvement made by any person familiar with the technical field based on the technical solution disclosed in the present invention shall fall within the protection scope of the present invention.

Claims

1. A green, energy-saving, low-surface-activity absorbent cotton pretreatment process, characterized in that The steps include: Step 1: Degreasing and oxygen bleaching The raw cotton after cake pressing is hung into the drum bleaching machine, pure water rich in microbubbles is passed through, and then the pretreatment agent and sodium hydroxide are added, and microbubbles are continued to be passed through and the temperature is raised to 50°C, and then hydrogen peroxide is added, and the temperature is kept after the temperature is raised; Step 2: Wash 2a. Preliminary washing: After degreasing and oxygen bleaching, the raw cotton is left in the drum bleaching machine, the degreasing and oxygen bleaching liquid is emptied, and microbubble water is added to wash at room temperature for 20 minutes and then emptied. The number of washing times is determined according to the water quality SS; 2b. Neutralization washing: Add microbubble washing water and citric acid at room temperature, adjust the pH value of the washing water in the drum bleaching machine to 7-8, and drain the washing water after washing for 20 minutes; Step 3: Remove from the cylinder The neutralized and washed absorbent cotton is removed from the drum bleaching machine and subjected to centrifugal dehydration and drying processes.

2. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 1, characterized in that: In step 1, the microbubble concentration in the degreasing oxygen bleaching section is 10 3 -10 6 / ml, the microbubble diameter is between 10-300μm accounting for more than 50%, and the microbubble introduction time is 8-10min.

3. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 2 is characterized by: Microbubbles with a diameter between 10-300μm account for ≥50% of the total microbubbles.

4. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 2, characterized in that: The steam pressure in the cylinder is controlled to ≤0.5MPa.

5. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 1, characterized in that: In step 1, the degreasing oxygen bleaching holding temperature is set at 90±5°C and the holding time is 60 minutes.

6. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 1, characterized in that: In step 2, the microbubble concentration in the water washing section is ≥10 4 Pieces / ml.

7. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 6, characterized in that: In the washing section, microbubbles with diameters between 1-200μm account for ≥60% of the total microbubbles.

8. The green, energy-saving, low-surface-activity absorbent cotton pretreatment process according to claim 1, characterized in that: In step 2, the effluent from the initial washing section has a SS of ≤30 mg / L, and the effluent from the neutralization washing section has a SS of ≤20 mg / L.

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