What is the performance and function of polyester fiber

Update: 12-11-2021
Abst: Polyester fiber, commonly known as "polyester". It is a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic a...
Polyester fiber, commonly known as "polyester". It is a synthetic fiber obtained by spinning polyester formed by polycondensation of organic dibasic acid and diol, referred to as PET fiber, which belongs to a high molecular compound. Invented in 1941, it is currently the largest variety of synthetic fibers. The biggest advantage of polyester fiber is that it has good wrinkle resistance and shape retention, and has high strength and elastic recovery ability. It is durable, anti-wrinkle, non-ironing, and non-sticky.
Performance and function
Physical properties
①Color. Polyester is generally milky white with mercerizing, matting agent TiO2 should be added before spinning to produce dull products, brighteners should be added to produce pure white products, and pigments or dyes should be added to the spinning melt to produce colored yarns.
②Surface and cross-sectional shape. The surface of conventional polyester is smooth, and the cross-section is nearly round. If a special-shaped spinneret is used, fibers with special cross-sectional shapes can be made, such as triangular, Y-shaped, hollow, and other special-shaped cross-section filaments.
③Density. When polyester is completely amorphous, its density is 1.333g/cm3. When fully crystallized, it is 1.455g/cm3. Generally, polyester has a higher degree of crystallinity, with a density of 1.38~1.40g/cm3, which is similar to wool (1.32g/cm3).
④ Moisture regain. In the standard state, the moisture regain of polyester is 0.4%, which is lower than that of acrylic (1%~2%) and nylon (4%). Polyester has low moisture absorption, so its wet strength decreases less, and the fabric has good washability and wearability. However, static electricity is serious during processing and wearing, and the fabric has poor air permeability and moisture absorption.
⑤ Thermal performance. The softening point T of polyester is 230-240℃, the melting point Tm is 255-265℃, and the decomposition point T is about 300℃. Polyester can burn in fire, curl, and melt into beads, with black smoke and aromatic smell.
⑥ Light resistance. Its light resistance is second only to acrylic fiber. The light resistance of polyester is related to its molecular structure. Polyester only has a strong absorption band in the 315nm wavelength region, so it loses only 60% of its strength after 600h of sunlight, which is similar to cotton.
⑦Electrical performance. Polyester has poor electrical conductivity due to its low moisture absorption. The dielectric constant in the range of -100~+160℃ is 3.0~3.8, which is an excellent insulator.