Environment-friendly synthetic fiber oil removal process based on micro-nano bubbles

Abstract

The invention discloses an environment-friendly synthetic fiber oil removal process based on micro-nano bubbles, the characteristics of high permeability and high penetrating power of the micro-nano bubbles are utilized, washing assistants do not need to be added, dyeing fiber oil stains are removed in an auxiliary mode through different water temperatures, and the process specifically comprises the steps of a preparation stage, medium-temperature water washing, normal-temperature water washing and aftertreatment. The method is simple in process and mild in condition, avoids damage of chemical agents to fibers and pollution of the chemical agents to the environment, has wide applicability and is suitable for treating oil agent residues of various synthetic fibers; gradient water temperature is adopted to reduce energy consumption, and fiber damage caused by high temperature is avoided; and by accurately controlling the diameter of the micro-nano bubbles and the gas-liquid ratio, the consistency and repeatability of the oil removal effect are ensured. The process has remarkable technical advantages and economic and environment-friendly benefits, and is expected to be widely applied and popularized in synthetic fiber oil stain cleaning.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of synthetic fiber processing, and specifically relates to an environmentally friendly synthetic fiber oil removal process based on micro-nano bubble technology, which is suitable for the oil residue treatment of polyester, nylon, regenerated polyester, composite fiber and other synthetic fibers. BACKGROUND

[0002] In the process of synthetic fiber processing, oil removal treatment is a crucial link. Residual oil can have a serious impact on subsequent processes and product quality. For example, if the mineral oil and ester lubricant used during polyester spinning are not removed completely, it will cause uneven dyeing, resulting in color spots and inconsistent color on the fabric surface; the silicone oil and antistatic agent remaining on the surface of nylon can easily cause dyeing color spots, greatly affecting the appearance and quality of the product; the complex oil impurities in the recycled polyester fiber need to be cleaned in stages to meet the requirements of subsequent processing; the fluorine-based waterproof agent remaining on the polyester / spandex composite fabric can cause dyeing difficulties.

[0003] Synthetic fibers use a variety of oils, including mineral oil for polyester, silicone oil for nylon, residual impurities for recycled polyester, and fluorine-based waterproof agent for composite fabric. Existing oil removal methods can be divided into four categories: alkali washing and surfactant treatment (such as polyester filament 98℃ alkali washing); weak acid mild treatment (such as nylon weak acid oil removal); segmented temperature rise and special agent treatment (such as fluorine-based waterproof agent decomposition); continuous flat process (such as large-scale production of polyester woven fabric). However, these methods generally rely on chemical agents and are mainly treated at high temperatures, which has a series of problems such as high COD pollution, damage to fibers, poor process adaptability, high energy consumption and cost.

[0004] Currently, existing oil removal processes face many technical bottlenecks:

[0005] 1. Poor process adaptability: different fibers require different processes, increasing production operation difficulty and equipment investment cost.

[0006] 2. Heavy environmental load: large water consumption, and the wastewater generated by oil removal has complex composition, high chemical oxygen demand (COD), and general biodegradability. The amount of sludge generated during subsequent wastewater treatment is large, the disposal cost is high, and the overall environmental load is heavy. SUMMARY

[0007] In view of the shortcomings of the prior art, the present application provides an environmentally friendly synthetic fiber oil removal process based on micro-nano bubbles. This method is environmentally friendly, simple in process, widely applicable, and efficient and environmentally friendly.

[0008] The environmentally friendly synthetic fiber oil removal process based on micro-nano bubbles of the present application comprises the following steps:

[0009] Step one: preparation phase

[0010] The oil-removing fibers to be cleaned are evenly placed in the cleaning cylinder (dyeing cylinder or treatment equipment), and it is checked whether the drainage, water inlet pipeline and stirring device of the cleaning cylinder are normally operated to ensure the smooth progress of the subsequent cleaning work.

[0011] Step two: medium-temperature water washing

[0012] Softened water with a temperature of 40-50°C is added to the cleaning cylinder, and the pH of the water solution in the cylinder is adjusted to 7-8; until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:8-1:12.

[0013] The gas-liquid mixture is supplemented to the cleaning cylinder using a micro-nano bubble generating device, the gas-liquid ratio and water temperature of the micro-nano bubble generating device are adjusted, the micro-nano bubble D50 of the gas-liquid mixture is monitored, the D50 of the micro-nano bubble is controlled to be less than 100 μm, the gas-liquid ratio of the gas-liquid mixture is 5-15%, the cleaning water temperature is maintained at 40-50°C, the cleaning is monitored, the conductivity and COD value of the water in the cylinder are monitored, and the number of times of the warm water cleaning is appropriately adjusted according to the type of the fiber, the degree of oil contamination and the packing density of the fiber and other factors.

[0014] The removal rate of the COD and conductivity of the wastewater after the water washing in this section accounts for more than 75% of the total removal rate of the COD and conductivity in the whole cleaning process. If the one-time cleaning does not meet the standard, step two can be repeated until the above requirements are met.

[0015] Preferably, the bath ratio of the medium-temperature water washing is 1:10, the water temperature of the medium-temperature water washing is 45±2°C, the medium-temperature water washing time is 15 minutes, and the number of times of the medium-temperature water washing is 2.

[0016] Step three: normal-temperature water washing

[0017] The cleaning liquid in the cleaning cylinder after the medium-temperature water washing is emptied, softened water at the ambient temperature is added to the cleaning cylinder until the softened water completely immerses the synthetic fibers, and the bath ratio is controlled at 1:8-1:10. The gas-liquid ratio of the micro-nano bubble generating device is adjusted, the micro-nano bubble size distribution is monitored to ensure that the D50 is less than 100 μm, and the cleaning time is controlled at 10-20 minutes. The specific time is appropriately adjusted according to the type of the fiber, the degree of oil contamination and the packing density of the fiber and other factors.

[0018] After the completion of step three, the conductivity value of the cleaning water is monitored online, if the COD is less than 100 mg / L and the conductivity is less than 200 us / cm, the cleaning process is completed. If the COD and conductivity indicators exceed the standard after the normal-temperature water washing, step three is repeated until the COD of the wastewater after the cleaning is less than 100 mg / L and the conductivity is less than 200 us / cm to complete the cleaning.

[0019] Further, the normal-temperature water washing time is 15 minutes, and the number of times of the normal-temperature water washing is 1.

[0020] Preferably, the gas-liquid ratio of the gas-liquid mixture of the medium-temperature water washing and the normal-temperature water washing is 1:10, and the micro-nano bubble D50 is 50±10 μm.

[0021] Step four: post-treatment

[0022] The normal-temperature water washed synthetic fibers are centrifuged and dehydrated and dried (40-50℃), and after drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0023] The fibers include one or more of polyester, polyamide, regenerated polyester, and polyester / spandex composite fibers.

[0024] The method uses micro-nano bubbles (D50 < 100 μm) and warm water to achieve efficient cleaning of synthetic fibers. Micro-nano bubbles have high specific surface area to enhance oil adsorption, and their surface charge promotes oil dispersion. The cavitation effect generated by shrinkage can strip the oil on the surface of the fibers. In the gradient cleaning process, warm water softens the oil and enhances the cavitation effect. The optimized bubble size can efficiently remove the oil without damaging the fibers. The bubble flotation effect separates the adsorbed oil, small-sized bubbles penetrate the fiber pores to dissolve the oil, and the cavitation effect assists in emulsification and dispersion. This method is especially suitable for cleaning synthetic fibers with high oil content and meets the needs of industrial scale application.

[0025] The method uses the high penetration and high penetration force of micro-nano bubbles to effectively remove oil from dyed fibers without adding any cleaning aids. Compared with existing technologies, the method has the following advantages:

[0026] 1. Cleaning characteristics: The oil removal process in the invention does not require the addition of cleaning aids, and the process is simple and mild, avoiding damage to the fibers and pollution to the environment, reducing wastewater discharge and pollutants, and having significant environmental advantages.

[0027] 2. Wide applicability: The oil removal process in the invention is suitable for different types of synthetic fibers, including polyester filaments, polyester ultra-fine fibers, polyamide, regenerated polyester, and polyester / spandex composite fabrics, etc., and has strong broad-spectrum characteristics. Whether it is a conventional synthetic fiber fabric or a special fiber fabric containing complex oil residues, the process can achieve good oil removal effect, greatly improving the universality and practicality of the process.

[0028] 3. Energy saving: Compared with traditional high-temperature processes, the invention uses gradient water temperature (40-50℃ warm water and cold water) to reduce energy consumption, while avoiding fiber damage caused by high temperature, and has significant economic benefits.

[0029] 4. Process stability: By precisely controlling the micro-nano bubble diameter (D50<100um) and gas-liquid ratio, the consistency and repeatability of the oil removal effect are ensured, and product quality problems caused by process fluctuations are reduced.

[0030] In summary, the present application provides a new synthetic fiber oil removal process method, which has significant technical advantages and economic benefits, and is expected to be widely used and popularized in future synthetic fiber oil cleaning. DETAILED DESCRIPTION

[0031] The technical solutions of the present application are further analyzed and described below through specific examples.

[0032] Example 1:

[0033] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are cleaned and removed using the cleaning process of the present application, and then post-treated, the detailed steps are as follows:

[0034] Step one: preparation stage

[0035] Select the polyester filament woven fabric for dyeing, which has obvious oil stains, weaving defects and sizing residues. Place it evenly in the cleaning cylinder, check the equipment after normal operation,

[0036] Step two: medium temperature washing

[0037] Add softened water with a temperature of 40-50℃ to the cleaning cylinder, adjust the pH of the water solution in the cylinder to 7-8; until the softened water completely immerses the synthetic fiber, the bath ratio is controlled at 1:10; use the micro-nano bubble generating device to supplement the gas-liquid mixture into the cleaning cylinder, by adjusting the gas-liquid ratio and water temperature of the micro-nano bubble generating device, monitor the micro-nano bubble D50 of the gas-liquid mixture, control the D50 of the micro-nano bubble =100±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, keep the cleaning water temperature at 45±2℃ for 15min, then empty the cleaning liquid, repeat step two once.

[0038] Step three: normal temperature washing

[0039] Empty the cleaning liquid in the cleaning cylinder after warm water washing, add softened water at ambient temperature into the cleaning cylinder, until the softened water completely immerses the synthetic fiber, the bath ratio is controlled at 1:10. By adjusting the gas-liquid ratio of the micro-nano bubble generating device, controlling the D50 of the micro-nano bubble =100±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, cleaning for 15min, then empty the cleaning liquid, monitor the conductivity value and COD value of the cleaning water in the cleaning cylinder online.

[0040] Step four: post-treatment

[0041] The synthetic fibers are centrifuged and dehydrated, and then dried. After drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0042] Example 2:

[0043] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are removed by the cleaning process of the application, and then post-processing is performed. The detailed steps are as follows:

[0044] Step one: preparation stage

[0045] Select the polyester filament woven fabric for dyeing. The greige fabric has obvious oil stains, weaving defects and sizing residues. Place it evenly in the cleaning cylinder, check the equipment, and then

[0046] Step two: medium temperature washing

[0047] Add softened water with a temperature of 40-50℃ to the cleaning cylinder, adjust the pH of the water solution in the cylinder to 7-8; until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:10; use a micro-nano bubble generating device to supplement the gas-liquid mixture into the cleaning cylinder, adjust the gas-liquid ratio and water temperature of the micro-nano bubble generating device, monitor the micro-nano bubble D50 of the gas-liquid mixture, control the D50 of the micro-nano bubble = 20±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, maintain the cleaning water temperature at 45±2℃ for 15 minutes, then empty the cleaning liquid, and repeat step two once.

[0048] Step three: normal temperature washing

[0049] Empty the cleaning liquid in the warm water washed cleaning cylinder, add softened water at ambient temperature to the cleaning cylinder, until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:10. Adjust the gas-liquid ratio of the micro-nano bubble generating device, control the D50 of the micro-nano bubble = 20±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, wash for 15 minutes, then empty the cleaning liquid, and monitor the cleaning water conductivity value and COD value in the cleaning cylinder online.

[0050] Step four: post-processing

[0051] The synthetic fibers are centrifuged and dehydrated, and then dried. After drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0052] Example 3:

[0053] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are removed by the cleaning process of the application, and then post-processing is performed. The detailed steps are as follows:

[0054] Step one: preparation stage

[0055] Select the polyester filament woven fabric for dyeing, the greige goods has obvious oil stains, weaving defects and sizing residue. Uniformly stack it into the cleaning cylinder, check the equipment after normal,

[0056] Step two: medium temperature water washing

[0057] Add softened water with temperature of 40-50℃ into the cleaning cylinder, adjust the pH of the water solution in the cylinder to 7-8; until the softened water completely immerses the synthetic fiber, control the bath ratio to 1:10; supplement the gas-liquid mixture into the cleaning cylinder using the micro-nano bubble generating device, monitor the micro-nano bubble D50 of the gas-liquid mixture by adjusting the gas-liquid ratio of the micro-nano bubble generating device and the water temperature, control the D50 of the micro-nano bubble to 50±10um, the gas-liquid ratio of the gas-liquid mixture to 1:10, keep the cleaning water temperature to 45±2℃ for 20min, then empty the cleaning liquid again, repeat step two once.

[0058] Step three: normal temperature water washing

[0059] Empty the cleaning liquid in the cleaning cylinder after warm water washing, add softened water with ambient temperature into the cleaning cylinder until the softened water completely immerses the synthetic fiber, control the bath ratio to 1:10. Control the D50 of the micro-nano bubble to 50±10um by adjusting the gas-liquid ratio of the micro-nano bubble generating device, the gas-liquid ratio of the gas-liquid mixture to 1:10, wash for 20min, then empty the cleaning liquid again, monitor the conductivity value and COD value of the cleaning water in the cleaning cylinder online.

[0060] Step four: post-treatment

[0061] After centrifugal dewatering and drying of the synthetic fiber, randomly take fiber samples from different parts for appearance and oil content detection after drying.

[0062] Example 4:

[0063] The oil stains, weaving defects and sizing residue on the dyed polyester filament woven fabric are removed by using the cleaning process of the application for cleaning and removing, and then post-treatment, the detailed steps are as follows:

[0064] Step one: preparation stage

[0065] Select the polyester filament woven fabric for dyeing, the greige goods has obvious oil stains, weaving defects and sizing residue. Uniformly stack it into the cleaning cylinder, check the equipment after normal,

[0066] Step two: medium temperature water washing

[0067] The softened water with a temperature of 40-50 DEG C is added into the cleaning cylinder, the pH of the water solution in the cylinder is adjusted to 7-8; until the softened water completely immerses the synthetic fiber, the bath ratio is controlled to be 1:10; the gas-liquid mixture is supplemented into the cleaning cylinder by using the micro-nano bubble generating device, the micro-nano bubble D50 of the gas-liquid mixture is monitored by adjusting the gas-liquid ratio of the micro-nano bubble generating device and the water temperature, the micro-nano bubble D50 is controlled to be 50+ / -10 um, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning water temperature is kept at 45+ / -2 DEG C, and the cleaning is performed for 20 min, and then the cleaning liquid is emptied.

[0068] Step three: normal temperature water washing

[0069] The cleaning liquid in the cleaning cylinder after the warm water washing is emptied, the softened water at the ambient temperature is added into the cleaning cylinder until the softened water completely immerses the synthetic fiber, the bath ratio is controlled to be 1:10. The micro-nano bubble D50 is controlled to be 50+ / -10 um by adjusting the gas-liquid ratio of the micro-nano bubble generating device, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning is performed for 20 min, and then the cleaning liquid is emptied, and the water conductivity value and the COD value in the cleaning cylinder are monitored online.

[0070] Step four: post-treatment

[0071] The synthetic fiber is centrifuged and dehydrated, and then dried, and after drying, the fiber samples are randomly taken from different parts for appearance and oil content detection.

[0072] Example 5:

[0073] The oil stains, weaving defects and sizing residue on the dyed polyester filament woven fabric are removed by using the cleaning process of the application, and then post-treatment is performed, and the detailed steps are as follows:

[0074] Step one: preparation stage

[0075] The polyester filament woven fabric for dyeing is selected, and the grey fabric has obvious oil stains, weaving defects and sizing residue. The grey fabric is uniformly stacked into the cleaning cylinder, the equipment is checked to be normal,

[0076] Step two: medium temperature water washing

[0077] The softened water with a temperature of 25-30 DEG C is added into the cleaning cylinder, the pH of the water solution in the cylinder is adjusted to 7-8; until the softened water completely immerses the synthetic fiber, the bath ratio is controlled to be 1:10; the gas-liquid mixture is supplemented into the cleaning cylinder by using the micro-nano bubble generating device, the micro-nano bubble D50 of the gas-liquid mixture is monitored by adjusting the gas-liquid ratio of the micro-nano bubble generating device and the water temperature, the micro-nano bubble D50 is controlled to be 50+ / -10 um, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning water temperature is kept at 25+ / -2 DEG C, and the cleaning is performed for 15 min, and the step two is repeated once.

[0078] Step three: normal temperature water washing

[0079] The cleaning solution in the cleaning cylinder after warm water washing is emptied, and softened water at ambient temperature is added into the cleaning cylinder until the softened water completely immerses the synthetic fibers, and the bath ratio is controlled at 1:10. By adjusting the gas-liquid ratio of the micro-nano bubble generating device, the D50 of the micro-nano bubbles is controlled at 50±10 um, the gas-liquid ratio of the gas-liquid mixture is 1:10, and after cleaning for 15 min, the cleaning solution is emptied again, and the conductivity value and the COD value of the cleaning water in the cleaning cylinder are monitored online.

[0080] Step four: post-treatment

[0081] After the synthetic fibers are centrifuged and dehydrated, they are dried, and after drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0082] Example 6:

[0083] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are removed by using the cleaning process of the application, and then post-treatment is performed, and the detailed steps are as follows:

[0084] Step one: preparation stage

[0085] Select the polyester filament woven fabric for dyeing, and the gray fabric has obvious oil stains, weaving defects and sizing residues. The fabric is evenly stacked into the cleaning cylinder, and after checking that the equipment is normal,

[0086] Step two: warm water washing

[0087] Softened water at a temperature of 55-60℃ is added into the cleaning cylinder, the pH of the aqueous solution in the cylinder is adjusted to 7-8; until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:10; the micro-nano bubble generating device is used to supplement the gas-liquid mixture into the cleaning cylinder, by adjusting the gas-liquid ratio of the micro-nano bubble generating device and the water temperature, the D50 of the micro-nano bubbles of the gas-liquid mixture is monitored, the D50 of the micro-nano bubbles is controlled at 50±10 um, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning water temperature is maintained at 55±2℃, and cleaning is performed for 15 min, then the cleaning solution is emptied again, and step two is repeated once.

[0088] Step three: normal temperature water washing

[0089] The cleaning solution in the cleaning cylinder after warm water washing is emptied, and softened water at ambient temperature is added into the cleaning cylinder until the softened water completely immerses the synthetic fibers, and the bath ratio is controlled at 1:10. By adjusting the gas-liquid ratio of the micro-nano bubble generating device, the D50 of the micro-nano bubbles is controlled at 50±10 um, the gas-liquid ratio of the gas-liquid mixture is 1:10, and after cleaning for 15 min, the cleaning solution is emptied again, and the conductivity value and the COD value of the cleaning water in the cleaning cylinder are monitored online.

[0090] Step four: post-treatment

[0091] The synthetic fibers are centrifuged and dehydrated, and then dried. After drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0092] Example 7

[0093] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are removed by the cleaning process of the application, and then post-treated. The detailed steps are as follows:

[0094] Step one: preparation stage

[0095] Select the polyester filament woven fabric for dyeing. The greige fabric has obvious oil stains, weaving defects and sizing residues. Place it evenly in the cleaning cylinder, check the equipment, and then

[0096] Step two: medium temperature washing

[0097] Add softened water with a temperature of 40-50℃ to the cleaning cylinder, adjust the pH of the water solution in the cylinder to 7-8; until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:10; use a micro-nano bubble generating device to supplement the gas-liquid mixture into the cleaning cylinder, adjust the gas-liquid ratio and water temperature of the micro-nano bubble generating device, monitor the micro-nano bubble D50 of the gas-liquid mixture, control the D50 of the micro-nano bubble = 50±10um, the gas-liquid ratio of the gas-liquid mixture is 1:20, maintain the cleaning water temperature at 45±2℃ for 15min, then empty the cleaning liquid, and repeat step two once.

[0098] Step three: normal temperature washing

[0099] Empty the cleaning liquid in the warm water washed cleaning cylinder, add softened water at ambient temperature into the cleaning cylinder, until the softened water completely immerses the synthetic fibers, the bath ratio is controlled at 1:10. Adjust the gas-liquid ratio of the micro-nano bubble generating device, control the D50 of the micro-nano bubble = 50±10um, the gas-liquid ratio of the gas-liquid mixture is 1:20, wash for 15min, then empty the cleaning liquid, and monitor the cleaning water conductivity value and COD value in the cleaning cylinder online.

[0100] Step four: post-treatment

[0101] The synthetic fibers are centrifuged and dehydrated, and then dried. After drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0102] Example 8

[0103] The oil stains, weaving defects and sizing residues on the dyed polyester filament woven fabric are removed by the cleaning process of the application, and then post-treated. The detailed steps are as follows:

[0104] Step one: preparation stage

[0105] Select the polyester filament woven fabric for dyeing, the greasy dirt, the weaving defect and the sizing residue exist obviously in the grey fabric. The grey fabric is uniformly stacked into the cleaning cylinder, the equipment is checked to be normal,

[0106] Step two: medium temperature water washing

[0107] The softened water with the temperature of 40-50℃ is added into the cleaning cylinder, the pH of the water solution in the cylinder is adjusted to 7-8; until the softened water completely immerses the synthetic fiber, the bath ratio is controlled to be 1:10; the gas-liquid mixture is supplemented into the cleaning cylinder by using the micro-nano bubble generating device, by adjusting the gas-liquid ratio of the micro-nano bubble generating device and the water temperature, the micro-nano bubble D50 of the gas-liquid mixture is monitored, the D50 of the micro-nano bubble is controlled to be 50±10um, the gas-liquid ratio of the gas-liquid mixture is 3:20, the cleaning water temperature is kept to be 45±2℃, the cleaning is carried out for 15 minutes, then the cleaning liquid is emptied, and the step two is repeated once.

[0108] Step three: normal temperature water washing

[0109] The cleaning liquid in the cleaning cylinder after the warm water washing is emptied, the softened water at the ambient temperature is added into the cleaning cylinder, until the softened water completely immerses the synthetic fiber, the bath ratio is controlled to be 1:10. The D50 of the micro-nano bubble is controlled to be 50±10um by adjusting the gas-liquid ratio of the micro-nano bubble generating device, the gas-liquid ratio of the gas-liquid mixture is 3:20, the cleaning is carried out for 15 minutes, then the cleaning liquid is emptied, and the water conductivity value and the COD value in the cleaning cylinder are monitored online.

[0110] Step four: post-treatment

[0111] After the centrifugal dewatering of the synthetic fiber, the synthetic fiber is dried, after the drying, the fiber samples are randomly taken from different parts for appearance and oil content detection.

[0112] Example 9:

[0113] The greasy dirt, the weaving defect and the sizing residue on the dyed polyester filament woven fabric are cleaned and removed by using the cleaning process of the application, and then the post-treatment is carried out, and the detailed steps are as follows:

[0114] Step one: preparation stage

[0115] Select the polyester filament woven fabric for dyeing, the greasy dirt, the weaving defect and the sizing residue exist obviously in the grey fabric. The grey fabric is uniformly stacked into the cleaning cylinder, the equipment is checked to be normal,

[0116] Step two: medium temperature water washing

[0117] The softened water with a temperature of 40-50℃ is added into the cleaning tank, the pH of the water solution in the tank is adjusted to 7-8; until the softened water completely immerses the synthetic fibers, the bath ratio is controlled to be 1:10; the gas-liquid mixture is supplemented into the cleaning tank by using the micro-nano bubble generating device, by adjusting the gas-liquid ratio and water temperature of the micro-nano bubble generating device, the micro-nano bubble D50 of the gas-liquid mixture is monitored, the D50 of the micro-nano bubble is controlled to be 50±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning water temperature is kept at 45±2℃ for 15 minutes, then the cleaning liquid is emptied, and the step two is repeated.

[0118] Step three: normal temperature water washing

[0119] The cleaning liquid in the cleaning tank after the warm water washing is emptied, the softened water at ambient temperature is added into the cleaning tank until the softened water completely immerses the synthetic fibers, the bath ratio is controlled to be 1:10. By adjusting the gas-liquid ratio of the micro-nano bubble generating device, the D50 of the micro-nano bubble is controlled to be 50±10um, the gas-liquid ratio of the gas-liquid mixture is 1:10, the cleaning is carried out for 15 minutes, then the cleaning liquid is emptied, and the conductivity value and COD value of the cleaning water in the cleaning tank are monitored online.

[0120] Step four: post-treatment

[0121] After the synthetic fibers are centrifuged and dehydrated, they are dried, and after drying, fiber samples are randomly taken from different parts for appearance and oil content detection.

[0122] The COD value of the cleaning water is detected by using an online detector (the detection range is: 0-5000mg / L, the measurement accuracy is: ±5%FS); the conductivity value of the cleaning water is detected by using an online conductivity detector (the detection range is: 0.00us / cm to 20ms / cm, the measurement accuracy is: ±1%FS). The oil removal rate is calculated, the oil content of the synthetic fiber fabric before cleaning is measured by using the Soxhlet extraction method in the national standard GB / T 6504-2017 "Chemical fiber oil content test method", and the mass of the synthetic fiber fabric before and after cleaning is dried to constant weight according to the national standard GB / T 6503-2017 "Chemical fiber moisture regain test method". The oil removal rate is calculated according to the following formula.

[0123]

[0124] In the formula: Y is the oil removal rate; M0 is the mass of the synthetic fiber fabric before cleaning; M1 is the mass of the synthetic fiber fabric after cleaning; Q is the initial oil content of the fabric.

[0125] Embodiments 1-9 are part of the data of process optimization for cleaning and removing oil stains, fabric defects and sizing residues on dyed polyester filament woven fabric using the process and method of the present application. From the process condition optimization, it can be seen that the particle size distribution D50 of the micro-nano bubbles in the cleaning water, the water temperature and the number of warm water washing have a greater impact on the cleaning effect of the oil stains. The optimal process condition is embodiment 9, and the oil content of the fabric after cleaning is less than 0.5%, and the oil removal rate reaches 94.7%.

[0126]

[0127] Embodiments 10-15 are oil stain cleaning for different types of synthetic fibers. According to the process scheme of embodiment 9, oil stain residues on polyester ultra-fine fibers (imitation silk), silicon oil residues on some areas of nylon 66 elastic knitted fabric (containing spandex), heavy fluorine-based oil agent residues on polyester / spandex composite fabric (containing fluorine-based waterproof agent), medium silicon oil and antistatic agent residues on nylon ultra-fine fibers (sports fabric), and cross-contamination type oil agent residues on composite fibers (polyester / nylon interwoven) are cleaned and removed. The results show that the present method is suitable for oil stain cleaning of various synthetic fibers, and the oil removal rate is more than 85%, which reflects the high efficiency of the oil removal effect of the process and method of the present application. The COD of the cleaning water after cleaning is less than 200 mg / L, which greatly reduces the pressure of wastewater treatment.

[0128]

[0129] In summary, the method used in the present application fully utilizes the high permeability and high penetration force characteristics of micro-nano bubbles. Without adding any washing aids, the oil stains on dyed fibers can be effectively removed with the aid of a specific water temperature condition. The method innovatively combines micro-nano bubble gas-liquid mixture with warm water and carries out oil stain cleaning work for different types of synthetic fibers.

[0130] The actual application results show that the oil removal effect of the fabric cleaned by this method is significant, and the COD value of the wastewater after washing is also at a low level. The whole washing process is not only simple, but also has very wide applicability, which can meet the needs of various synthetic fiber oil agent residue treatment.

[0131] In terms of energy utilization, the present application uses a gradient water temperature design, which effectively reduces energy consumption and avoids damage to the fibers caused by high temperature treatment. In addition, by precisely controlling the diameter of the micro-nano bubbles and the gas-liquid ratio, the consistency and repeatability of the oil removal effect are ensured.

[0132] In summary, the process of the present application has significant technical advantages and economic benefits, and has great application potential in the field of synthetic fiber oil stain cleaning, and is expected to be widely promoted and applied.

[0133] The above embodiments are only preferred solutions of the present application, and are not intended to limit the scope of protection. Any person skilled in the art can make reasonable substitutions or improvements on the basis of the disclosed technical solutions, and all of these fall within the scope of protection of the present application.

Claims

1. An environmentally friendly synthetic fiber degreasing process based on micro-nano bubbles, characterized in that: By utilizing the high permeability and penetration of micro-nano bubbles, and with the assistance of gradient water temperature, the purpose of removing oil stains from dyed fibers can be achieved by controlling the diameter of micro-nano bubbles and the gas-liquid ratio.

2. The degreasing process according to claim 1, characterized in that... Includes the following steps: Step 1: Preparation Phase Evenly pile the fibers to be degreased into the cleaning tank, and check the drainage, water inlet pipes and agitation device of the cleaning tank to ensure that the subsequent cleaning work will proceed smoothly. Step 2: Wash with medium-temperature water Add softened water at a temperature of 40-50℃ to the cleaning tank and adjust the pH of the aqueous solution in the tank to 7-8; until the softened water completely submerges the synthetic fiber, the bath ratio is controlled at 1:8-1:12; use a micro-nano bubble generator to supplement the gas-liquid mixture into the cleaning tank, control the D50 of the micro-nano bubbles to <100μm, and monitor the conductivity and COD value of the cleaning water in the tank. Step 3: Wash with room temperature water After washing with medium-temperature water, drain the cleaning solution from the cleaning tank, add softened water at ambient temperature to the cleaning tank until the softened water completely submerges the synthetic fiber, and control the bath ratio at 1:8-1:10; adjust the gas-liquid ratio of the micro-nano bubble generator to control the D50 of the micro-nano bubbles to <100μm, and control the cleaning time at 10-20 minutes. Step 4: Post-processing The synthetic fibers can be centrifuged and dried after being washed with room temperature water.

3. The degreasing process according to claim 2, characterized in that: In step two, when using a micro-nano bubble generator to replenish the gas-liquid mixture into the cleaning tank, the gas-liquid ratio of the gas-liquid mixture is 5-15%, and the cleaning water temperature is maintained at 40-50℃.

4. The degreasing process according to claim 2, characterized in that: In step two, the medium-temperature water washing section controls the removal rate of COD and conductivity of the wastewater after washing to account for more than 75% of the total COD and conductivity removed during the cleaning process.

5. The degreasing process according to claim 2, characterized in that: In step two, the medium-temperature water bath ratio is 1:10, the water temperature for the medium-temperature water bath is 45±2℃, the washing time for the medium-temperature water bath is 15 minutes, and the number of washes is 2.

6. The degreasing process according to claim 2, characterized in that: In step three, the cleaning process is complete when the COD of the cleaned wastewater is less than 100 mg / L and the conductivity is less than 200 μS / cm.

7. The degreasing process according to claim 2, characterized in that: The gas-liquid ratio of the gas-liquid mixture for medium-temperature water washing and room-temperature water washing is 1:10, and the micro / nano bubble D50 is 50±10μm.

8. The degreasing process according to claim 2, characterized in that: The fiber includes one or more of polyester, nylon, recycled polyester, and polyester / spandex composite fiber.

Images