Polyester fiber, which is commonly known as "polyester", is a synthetic fiber made of organic dibasic acid and dibasic alcohol through chemical condensation, which belongs to a kind of polymer compounds. Its invention can be traced back to the 1930s, and today it is the most important kind of synthetic fiber.
Physical properties of polyester fibers
Color: Polyester is usually milky white with mercerization. The production of products without luster requires the addition of matting agent TiO2 before spinning, the production of pure white products requires the addition of whitening agents, and to obtain colored fibers, you need to add pigments or dyes during spinning.
Surface and cross section shape: The conventional polyester surface is smooth and the cross section is close to circular. If the special-shaped spinneret is used, it can be made into fibers with special cross-section shapes, such as triangles, Y shapes, and hollows.
Density: When completely amorphous, the density of polyester is 1.333g/cm³. When fully crystallized, it is 1.455g/cm³. Generally, polyester has a high crystallinity, with a density between 1.38 and 1.40g/cm³, similar to wool (1.32g/cm³).
Moisture regain: Under standard conditions, the moisture regain of polyester is 0.4%, which is lower than that of acrylic fiber (1%~2%) and nylon (4%). Polyester is less hygroscopic, so its strength drops less when wet, and the fabric is less prone to deformation after washing. However, the static electricity is serious during processing and wearing, and the air permeability and moisture absorption of the fabric are poor.
Thermal properties: The softening point of polyester is 230-240 ° C, the melting point is 255-265 ° C, and the decomposition point is about 300 ° C. Polyester burns in a fire, curls and melts into beads, with black smoke and an aromatic smell.
Light resistance: Its light resistance is second only to acrylic fiber. The light resistance of polyester is related to its molecular structure, and there is a strong absorption band in the 315 nm light wave region, so the strength is only 60% lost after 600 hours of sunlight, which is similar to cotton.
Electrical properties: Polyester has poor electrical conductivity due to low hygroscopic property. In the range of -100 ° C to +160 ° C, the dielectric constant is 3.0 to 3.8, which is an excellent insulator.
Mechanical properties of polyester fibers
High strength: the strength is 4~7cN/dtex in dry state, and slightly decreases in wet state.
Moderate extension: generally 20%~50%.
High modulus: Among synthetic fibers, polyester has the highest initial modulus, which can be as high as 14~17GPa. This makes the polyester fabric size stable, not easy to deform and out of shape, pleating lasting.
Good resilience: its elasticity is close to that of wool, when extended by 5%, it can be restored to its original shape soon after removing the load, and no wrinkles are left. Therefore, polyester fabrics are more wrinkle resistant than other fabrics.
Wear resistance: Its wear resistance is second only to nylon, ranking second in synthetic fibers, better than other natural fibers and synthetic fibers.
Mechanical properties of polyester fibers
High strength: the strength is 4~7cN/dtex in dry state, and slightly decreases in wet state.
Moderate extension: generally 20%~50%.
High modulus: Among synthetic fibers, polyester has the highest initial modulus, which can be as high as 14~17GPa. This makes the polyester fabric size stable, not easy to deform and out of shape, pleating lasting.
Good resilience: its elasticity is close to that of wool, when extended by 5%, it can be restored to its original shape soon after removing the load, and no wrinkles are left. Therefore, polyester fabrics are more wrinkle resistant than other fabrics.
Wear resistance: Its wear resistance is second only to nylon, ranking second in synthetic fibers, better than other natural fibers and synthetic fibers.
Polyester is a kind of synthetic fiber with high strength, high modulus and low water absorption, so it is widely used in civil fabrics and industrial fabrics. As a textile material, polyester staple fiber can be spun pure, but also suitable for blending with other fibers. It can be blended with natural fibers such as cotton, hemp, wool, and other chemical staple fibers such as viscose, acetate fiber, polyacrylonitrile fiber, etc. The cotton, wool and linen fabrics produced usually retain the excellent characteristics of polyester, such as wrinkle resistance, dimensional stability, wear resistance, and non-deformation after washing. By blending hydrophilic fiber, it can also reduce and improve some of the original shortcomings of polyester to a certain extent, such as reducing electrostatic phenomenon, improving dyeing performance, enhancing air permeability and so on.
What is polyester
What is polyester? Polyester is the name of polyester fiber, polyester fabric is a synthetic clothing fabric of chemical fiber. It has the characteristics of strong and durable, good elasticity, not easy to deformation, corrosion resistance, and clean and easy to wash and dry. Here is a detailed look at these characteristics of polyester fabric:
1, Durable
Polyester fabric fiber strength is high, short fiber strength is 2.6 ~ 5.7cN/dtex, high strength fiber is 5.6 ~ 8.0cN/dtex. Therefore, the impact strength of polyester fiber is much higher than that of ordinary fibers, and it is very strong and durable.
2. Good elasticity
Polyester fabric has higher strength and resilience, and its elasticity is close to wool. Therefore, the elasticity of polyester fabric is very good, and it can be restored to its original shape soon after repeated rubbing, and it is not easy to leave wrinkles.
3, Good heat resistance
Polyester is made by melt spinning process, belongs to thermoplastic fiber, melting point is higher than the average fiber melting point, so the heat resistance is also stronger than the average fiber, so polyester is a good heat resistance fiber.
4, Good wear resistance
The wear resistance of polyester fabric, second only to the wear resistance of nylon, is better than other natural fibers and synthetic fibers.