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JapanPolyester means polyester?
In life, when we go to buy clothes, the label says: polyester fiber. So we generally think that polyester fiber is polyester. In fact, in addition to polyester, there are many kinds of polyester fibers.
There are many varieties of polyester fibers:
1. Polyethylene terephthalate (PET) fiber
Second, polybutylene terephthalate (polybutylene terephthalate, PBT) fiber
3. Polypropylene terephthalate (PPT) fiber
1. Polyester - Polyethylene Terephthalate (PET)
The research on polyester began in the 1930s and was invented by British people such as Whinfield and Dickson. It was industrially produced in the United Kingdom in 1949 and in the United States in 1953. It is a product developed late in the large variety of synthetic fibers. But it's developing fast.
In China, fibers containing more than 85% polyethylene terephthalate are abbreviated as polyester, commonly known as "really good". There are many foreign commodity names, such as "Dacron" in the United States, "Tetoron" in Japan, "Terlenka" in the United Kingdom, and "Lavsan" in the former Soviet Union. Wait.
The characteristics of polyester
1. High strength
The strength of short fiber is 2.6~5.7cN/dtex, and the strength of high-strength fiber is 5.6~8.0cN/dtex. Due to its low hygroscopicity, its wet strength is basically the same as its dry strength. The impact strength is 4 times higher than that of nylon and 20 times higher than that of viscose fiber.
2. Good elasticity
The elasticity is close to that of wool, and it can almost fully recover when the elongation is 5%~6%. The wrinkle resistance exceeds other fibers, that is, the fabric does not wrinkle and has good dimensional stability. The elastic modulus is 22~141cN/dtex, which is 2~3 times higher than that of nylon. .Polyester fabric has high strength and elastic recovery ability, so it is strong and durable, wrinkle-resistant and iron-free.
3. Heat-resistant polyester is made by melt-spinning method, and the formed fibers can be heated and melted again, so they belong to thermoplastic fibers.
The melting point of polyester is relatively high, and the specific heat capacity and thermal conductivity are small, so the heat resistance and thermal insulation of polyester fiber are higher. Is the best of synthetic fibers.
4. Good thermoplasticity and poor melting resistance
Due to the smooth surface of polyester and the tight arrangement of internal molecules, polyester is the best heat-resistant fabric in synthetic fabrics. It has thermoplastic properties and can be made into pleated skirts with long-lasting pleats. At the same time, polyester fabric has poor melting resistance, and it is easy to form holes when encountering soot, sparks, etc. Therefore, try to avoid contact with cigarette butts, sparks, etc. when wearing.
5. Good abrasion resistance
The abrasion resistance is second only to the nylon with the best abrasion resistance, and it is better than other natural fibers and synthetic fibers.
6. Good light resistance
Lightfastness is second only to acrylic. The light fastness of polyester fabric is better than that of acrylic fiber, and its light fastness is better than that of natural fiber fabric. Especially the light fastness behind the glass is very good, almost on par with acrylic.
7. Corrosion resistance
Resistant to bleaches, oxidants, hydrocarbons, ketones, petroleum products and inorganic acids. Dilute alkali resistance, not afraid of mildew, but hot alkali can make it decompose. It also has strong anti-acid and alkali resistance and anti-ultraviolet ability.
8. Poor dyeability, but good color fastness, not easy to fade
Because there is no specific dyeing group on the polyester molecular chain, and the polarity is small, it is difficult to dye, the dyeability is poor, and the dye molecules are not easy to enter the fiber.
9. It has poor hygroscopicity and feels stuffy when wearing it. At the same time, it is easy to carry static electricity and contaminate dust, which affects the appearance and comfort.
However, it is very easy to dry after washing, and the wet strength hardly decreases, and it does not deform. It has good washability and wearability.
2. Polybutylene terephthalate (PBT)
Cationic yarn belongs to modified polyester, chemical name: polybutylene terephthalate (elastic polyester), abbreviation: PBT, and it is also represented by CD in the factory.
Modified polyester (PBT) that can be dyed with cationic dyes can be obtained by introducing acid groups that can bind cationic dyes into the PET molecular chain.
The commonly used cationic modified polyester filament is a new type of polyester product spun by introducing dimethyl isophthalate with polar group SO3Na into polyester chips. Its appearance is no different from that of ordinary polyester filaments. However, due to the use of ionic modification, not only the color absorption performance of the fiber is greatly improved, but also the crystallinity is reduced and the dye molecules are easy to penetrate, which makes the fiber easy to dye, the color absorption rate is increased, and the hygroscopicity is also improved.
Features of Cationic Polyester
Cationic polyester is easy to dye, and at the same time, it can increase the micropore of the fiber, improve the dyeing rate, air permeability and hygroscopicity of the fiber, so as to further adapt to the artificial silk of polyester fiber;
Through the simulation of silk, the fabric can be soft, breathable, comfortable, antistatic, and dyeable at room temperature and pressure;
Through cationic modification of multifunctional wool-like fabrics, the fabric can be made soft to the touch, anti-static, anti-pilling, co-dyeing with wool at room temperature and pressure.
Fabrics woven with cationic modified fibers have the following properties when dyed with cationic dyes:
1. Bright tone, good deep dyeing;
2. High hygroscopic performance;
3. Good light fastness and fading fastness;
4. Good compatibility of dyestuffs when dyeing with color combination;
5. Good stability in high temperature dye bath;
6. Small stain to other fibers including ordinary polyester fibers;
7. The diffusion rate to the inside of the fiber is fast, and there is no ring dyeing phenomenon;
8. The dyestuff has high stability when the pH value in the dyebath changes.
Third, elastic polyester - polytrimethylene terephthalate fiber (PPT)
PTT fiber is a new product in the polyester fiber family, the scientific name is polytrimethylene terephthalate fiber. The soft segment of PTT is propylene glycol, so its carbon-carbon chain is longer, which makes the fiber itself elastic.
PTT fiber characteristics
1. High elasticity
The macromolecular odd carbon structure of PTT determines that the fiber has high elasticity and good elastic recovery rate. As far as the tensile fiber is concerned, the relative breaking strength of PTT fiber is 20% ~ 30% lower than that of PET (polyester). Tests show that when the elongation at break is 25%, the relative breaking strength of PTT fiber is 3 ~ 3.5cN/ tex, but higher than wool or cotton, so it can improve the strength of blended yarn when blended with cotton and wool.
2. Good responsiveness
3. Excellent dyeing properties
Compared with PET fiber, PTT fiber has a significant dyeability which is one of its outstanding advantages. This is because the glass transition temperature of PTT fiber is 50~55oC. It can be boiled at atmospheric pressure without a carrier. At the same time, the penetration depth of dyes in PTT is significantly higher than that in PET at the same dyeing temperature, and the color is uniform and the color fastness is high.
4. The fiber has a high degree of fluffy
Due to the special molecular chain conformation and excellent tensile resilience of PTT fibers, high fluffy BCT carpet yarns can be obtained by the hot air crimping process. At the same time, the hand feeling of PTT fiber changes the hard feeling of PET fiber, and the effect of fine denier PET fiber can be achieved without alkali reduction and dyeing and finishing treatment. The fabric feels soft and comfortable, which is better than PA (polyamide).
5. Other properties
It has excellent wrinkle resistance and dimensional stability, weather resistance, stain resistance, easy dyeing and good barrier properties, can withstand gamma ray sterilization, and has improved hydrolytic stability, so it can be used to develop advanced apparel and functional fabrics.
4. Others
1. Normal temperature and pressure dyeable polyester fiber (ECDP)
Ordinary polyester fiber fabrics require high temperature and high pressure dyeing, which not only has low production efficiency, but also high production costs. In view of this shortcoming of polyester fiber, people add a small amount of sodium 3,5-isophthalate dimethyl sulfonate (SIPM) as the third monomer on the basis of the conventional polyester binary monomer, and then add a small amount of a certain molecular weight. As the fourth monomer, polyethylene glycol is polymerized by polycondensation, and a new variety of polyester obtained by melt spinning is ECDP fiber.
ECDP fiber can be dyed with cationic dyes under normal pressure boiling conditions, which is not only convenient for dyeing, but also has high dyeing rate, wide chromatogram and bright colors. Compared with ordinary polyester, ECDP fiber has a softer hand, and the mechanical properties of the fiber tend to be medium-strength, medium-stretching or low-strength and high-stretching, and the wearing performance is better; but its biggest disadvantage is poor heat resistance, repeated The loss of strength is obvious after ironing. At present, ECDP fibers have been widely used in clothing and decorative fabrics blended with cotton or spun.
2. Poly-thy-lene Naphtalate
PEN fiber is the abbreviation of polyethylene naphthalate fiber. Like polyester, PEN fiber is a semi-crystalline thermoplastic polyester material, which was originally introduced by KASA Company in the United States. Its production process is carried out by 2,6-dimethyl naphthalate (NDC) and ethylene glycol (EG). It is obtained by transesterification and then polycondensation; another method is to directly esterify 2,6-naphthalene dicarboxylic acid (NDCA) with ethylene glycol (EG), and then obtain it by polycondensation. The thermal stability of PEN can be improved by adding a small amount of compounds containing organic amines and organic phosphorus.
PEN fiber properties
Compared with conventional polyester, PEN fiber has better mechanical and thermal properties. Such as high strength, high modulus, good tensile properties, high rigidity; good heat resistance, dimensional stability, not easy to deform, good flame retardancy; good chemical resistance and hydrolysis resistance; UV resistance, aging resistance .
