Welcome To Shaoxing Shaoen Machinery Co.,Ltd! Consulting Hotline: 0575-82391120


About Us
Current location: Home > News

The status of hydrophilic finishing of polyester fiber

Date:2018-03-25Source:Shaoen Machinery
? ? ? ? Polyester's moisture regain is low, wearing comfort is poor, and improving the comfort of polyester is always a subject of the textile industry. At present, there are mainly two methods to improve the performance of polyester fabrics. The first is to use fiber synthesis technology to modify the polyester fiber structure in the textile spinning process, so that the fiber itself has hydrophilicity and antistatic properties, thus improving the polyester Taking performance. However, this method requires high technology and is rarely used in actual production. The second is to use fabric finishing technology to achieve the purpose of modification. Finishing modification is the introduction of hydrophilic groups on the macromolecule chain of polyester to form a hydrophilic protective layer on the surface of the polyester and achieve the purpose of changing the surface properties of the fiber. At present, practical methods for finishing are mainly surface graft polymerization and adsorption fixation of hydrophilic finishing agents.
? ? ? ? 1.Surface graft polymerization
? ? ? ? The graft polymerization of polyester generally uses irradiation of an initiator or high-energy radiation such as ultraviolet rays, co(60)7 rays, or low-temperature plasma treatment to radiatively graft the polyester surface. The surface of the fiber is made free radicals, and then the hydrophilic monomer is graft polymerized on the free radical to form a new surface layer having durable water absorption and antistatic properties. The application of low-temperature plasma in polymer surface modification has been a history of nearly 30 years. The application of polymer surface modification is extremely extensive, and developed countries have long been industrialized and applied. . The most important thing in plasma treatment is to choose the right gas. Hydrophobic and oil repellent treatment mainly choose fluorine-containing gas, while hydrophilic, clean and activation treatment use oxygen. The energy of the low-temperature plasma particles is generally about several to several tens of electron volts, which is greater than the binding energy of the polymer material, and can completely break the chemical bonds of the organic macromolecules to form new bonds.
? ? ? ? Plasma processing has the following advantages:
? ? ? ? (1)Good for environmental protection (dry processing, friendly to the environment, use of gas processing);
? ? ? ? (2)Processing technology and processing site safety (dry, non-chemical, closed system);
? ? ? ? (3)Improves product performance requirements (new possibilities, improved bond strength or filtration performance)
? ? ? ? (4)The production cost of a unit product is reduced and different processes can be performed on the same production line to improve product quality (change in product cost is low);
? ? ? ? (5)Satisfy product requirements (large range of process changes, surface modification as needed).
? ? ? ? However, China's research and application in this area are still at a relatively low level. One of the constraints is the limitation of the plasma. Especially under vacuum, it is neither economic nor efficient in industrialization, which greatly limits the promotion and utilization of this technology. At the same time, from the current development status, there is a lack of on-line testing methods on the experimental equipment, which makes it difficult to analyze the spectral lines. However, the complex formed in the middle of the plasma processing is difficult to capture because of the short life span, which causes great difficulties for the mechanism study. The lack of theoretical guidance on polyester surfaces has limited the development of this technology.
? ? ? ? Radiation grafting of terylene with initiators or high-energy radiation, as the degree of grafting increases, the hygroscopicity and antistatic properties of polyester also increase, but in the grafting process, the homopolymerization rate and the grafting rate are difficult to grasp. After the grafting, the strength decreased and the degree of extension increased. This method still stopped at the laboratory research stage H1. Because there are many problems in the graft modification of polyester surface, in the daily industrial production, the polyester fabric is often subjected to the finishing treatment by the adsorption and fixation of the finishing agent so as to achieve the purpose of modification.
? ? ? ? 2.Adsorption fixation of hydrophilic finishing agent
? ? ? ? The adsorption and fixation of the hydrophilic agent is to make the hydrophilic finishing agent adhere to the surface of the polyester evenly and firmly so as to form a layer of hydrophilic compound on the surface, thereby achieving the purpose of improving the hydrophilic property of the surface of the fiber. The hydrophilic film has a certain conductivity, which can improve the antistatic property of the material. This method is simple and easy to implement, the principle is also relatively mature, a wide range of applications, is a conventional method of polyester hydrophilic finishing. The composition of the hydrophilic finishing agent is generally a system composed of a water-absorbing and a fixing two-part material. The former is a water-soluble polymer containing a hydrophilic group, and the latter is a cross-linking agent that binds a water-soluble polymer and a fiber. Contains functional groups that react with polyester fibers and water-soluble polymers.
? ? ? ? 2.1 Polyethylene glycol (PEG)
? ? ? ? Polyester finishing with PEG can improve the fabric's water absorption, antistatic properties, wrinkle resilience, etc. However, when it is treated with PEG alone, because polyester is different from other fibers, it has less chemical reaction groups and tight aggregation structure. It is difficult to penetrate and fix, and its water solubility is good. Although the hydrophilicity, antistatic property, and oil resistance of the fabric after finishing have been improved correspondingly, the washed property of the fabric after finishing is poor. Adding 2D resin to the PEG to treat the polyester with a finishing solution made of 2D resin, the moisture regain can be increased from 0.4% to about 2%, the capillary effect can also reach about 30cm, and the wash-resistant effect is better because of the PEG and The 2D resin acts to produce a PEG-2D cross-linked product, this PEG. The 2D cross-linked product can be deposited between fibers, and the ether bond and hydroxyl group in the cross-linked product have strong hydrophilicity, so that the hydrophilicity of the polyester fabric is greatly improved. 5J. However, the finished polyester has a harder feel, permeability, moisture permeability, and strength, and the 2D resin contains formaldehyde, which not only damages the environment but also restricts the export of textiles. Therefore, PEG is used as a hydrophilic finishing agent for polyester. Not ideal.
? ? ? ? 2.2 Polyester and polyether resins
? ? ? ? When polyesters and polyethers are used for the finishing of polyesters, the polyesters and polyesters have the same molecular composition units and can form co-crystals at high temperatures, providing washability for hydrophilic finishing. Due to the hydrophilicity of the polyether component, the finished polyester fabric is improved in hydrophilicity, thereby improving the antistatic property and stain resistance of the polyester. The PemaloseTM polyester finishing agent produced by the United Kingdom belongs to the polyester polyether resin system. The moisture-permeable area of ??the polyester fabric treated with PennaloseTM can reach about 4cm2 after 1 minute, which not only changes the hydrophobic property of the fiber surface, but also enables the fiber to be on the fiber surface. Adsorption of moisture between the PeHnaloseTM layer and the fiber increases the electrical conductivity of the fiber, which reduces electrostatic build-up and makes the fabric less likely to attract dust. However, the high price of PennaloseTM reagent is not conducive to the reduction of production cost by the company. There is also a water-based substance Gx.12 of polyester and polyether block copolymerization. After the polyester is treated with polyester, the hydrophilicity and antistatic property of the polyester fabric are treated. There have been significant improvements, but the strength of the finished fabric has slightly decreased, and the finishing effect decreases as the number of washings increases.
? ? ? ? 2.3 Epoxy
? ? ? ? The block copolymer of polyethylene oxide and polyester is a hydrophilic finishing agent suitable for polyester. The molecular structure of the polymer contains polyoxyethylene ether bonds, and the epoxy ring opens under the action of the catalyst. Interlinked with fibers to form ether bonds, forming a continuous hydrophilic film on the surface of polyester, rich in hygroscopicity, crystalline polyester segments and the basic chemical structure of polyester are the same, so polyester has good compatibility, high temperature After baking, the co-solvent co-crystallizing effect of the finishing agent and terylene results in higher durability of the finish. However, such finishing agents are toxic and may be harmful to the production of workers and consumers. Therefore, they are not promoted.
? ? ? ? 2.4 Polysiloxanes
? ? ? ? Silicone hydrophilic finishing agents are polyether modified, epoxy polyether modified or amino polyether modified polysiloxane. These finishing agents have softness, antifouling and anti-resistance in addition to water absorption. Static electricity and other functions. Polyether. Siloxane is a polysiloxane modified by PEC. The silicone main chain is a hydrophobic group and the hydrophilic part is PEG. When it is used to treat polyester fabrics, the hydrophilic groups are perpendicular to the polyester structure. On the flat surface, it facilitates the penetration of water and the transfer of liquid through the fiber capillary, improving the hydrophilic properties of the polyester fabric. Due to the flexible spiral structure of polysiloxane, the softness of the polyester fabric is increased, and the hand feel is more.
? ? ? ? 2.5 Polyurethane type polyurethane type hydrophilic finishing agent is prepared by adding imidazole to a precontracted body made of PEG and diisocyanate, and blocking the isocyanate group therein to obtain a stable polyurethane finishing solution. When used, the finishing liquid is mixed with a polyfunctional amine compound, in which the imidazole group dissociates, the isocyanate group reappears, cross-links with each other on the polyester material to form a film with higher surface energy, and the hydrophilic property is improved. Polyether polyurethane molecular structure contains hydrophilic polyoxyethylene ether, hydrophilic properties. Developed by Guangdong Demei Fine Chemicals Co., Ltd., a weak anionic water-soluble moisture wicking finishing agent DM3402, which performs hydrophilic finishing on polyester fabrics, can increase the hydrophilic groups of polyester macromolecules, greatly improving the surface of the fiber to the water The absorption properties of the molecules improve the wearing comfort, but the color fastness and shade of certain color shades of the fabrics after finishing are affected, which brings difficulties to the use of such finishing agents.
? ? ? ? ?In 2003, Textilcolor of Switzerland developed a Biosoftd finishing agent for hygroscopicity and thermoregulatory finishing agents. Biosoftal is a surface-active modified polyurethane that can effectively convert hydrophobic fibers into hydrophilic fibers. Since water droplets enter the polyester from three directions, the treated fibers increase in volume when wet, allowing moisture to cross the fibers. Tests have shown that the diameter of water droplets can be increased by 3 to 4 times within 3 seconds, which means that moisture can be quickly transmitted to the surface of the material and spread in a wide range that can evaporate quickly, but its production cost is high. Difficult to use for a wide range of applications.
? ? ? ? 2.6 Chitosan
? ? ? ? Chitosan has the characteristics of ~ agent multi-energy, fabrics treated with chitosan to improve the polyester does not absorb moisture, static electricity and other shortcomings, while adding the fabric anti-bacterial, anti-mildew and other functions ... j. The use of chitosan for polyester antistatic finishing, the usual practice is to first alkali treatment of polyester fabrics, on the one hand to roughen the surface of the fiber, is conducive to the adhesion of chitosan coating; on the other hand is designed to make The ester groups in the surface polyester molecules undergo a certain degree of hydrolysis to generate a certain amount of carboxyl anions, which facilitates the combination of positive chitosan molecules and polyester. Then, the chitosan acetic acid solution is coated on the polyester fabric by rolling, baking and baking techniques, so that the chitosan film will be combined with the polyester through physical embedding and ionic bond and intermolecular force. Tests show that: after finishing, the moisture regain of polyester can be increased by several times; the tensile strength is improved; even at 20°C, relative humidity is 50, the electrostatic voltage is very low; due to insoluble in water and the degree of puffing in water is not large Therefore, it can prevent the decrease of the durability caused by water. By cross-linking the hydrophilic material, an insoluble conductive skin layer can be formed on the surface of the fiber, and the finished sample is immersed in the acetic acid solvent of the chitosan, and there is almost no phenomenon that the chitosan film peels off and falls off. This shows that the product has a certain antistatic durability. Due to the adhesive effect of chitosan, experiments have shown that the breathability of the finished fabric can be increased several times, the moisture permeability has also been significantly improved, and the fabric strength after finishing is not affected, chitosan is used as a polyester finishing agent Great room for development.
? ? ? ? 3.in conclusion
? ? ? ? The surface grafting polymerization can improve the hydrophilicity of the polyester and improve the handling performance. The development of the plasma processing technology and the radiation grafting technology limits its application development. The hydrophilic finishing agent can evenly and firmly attach to the surface of polyester to form hydrophilic compounds. The method is simple and easy, and there are many finishing agents. Among them, chitosan as a finishing agent has the advantages of versatility, environmental protection, durability, ease of use, and simple operation. It can improve the hydrophilicity, antistatic property and comfort of polyester, and is a new type of high value-added textiles. The means to meet the environmental protection requirements as a polyester finishing agent.
上一页Experience with nylon dyeing
下一页Introduction to Knitting Process Principles - Warp Knitting

Copyright @ 2018 www.sunmch.com ?All Rights ReservedCopyright : Shaoxing Shaoen Machinery Co.,Ltd. Add:No.15, Fanrong Road, Binhai New Town, Shaoxing , Zhejiang