High strengthThe dry state strength is 4~7cN/dex, while the wet state decreases.

Moderate extension degree为20%~50%

High modulusAmong the large varieties of synthetic fibers, polyester has the highest initial modulus, and its value can be as high as 14~17GPa, which makes polyester fabric size stable, not deformed, not out of shape, pleats lasting.

Good resilienceIts elasticity is close to that of wool, and when elongated by 5%, it can recover almost completely after going to load. Therefore, the wrinkle resistance of polyester fabric exceeds that of other fiber fabrics.

Abrasion resistanceIts abrasion resistance is second only to nylon and exceeds that of other synthetic fibers, with almost the same abrasion resistance.

Acid resistancePolyester to acid (especially organic acid) is very stable, at 100 ℃ in the mass fraction of 5% hydrochloric acid solution immersed in 24h, or at 40 ℃ in the mass fraction of 70% sulfuric acid solution immersed in 72h, its strength are no loss, but at room temperature can not resist the action of concentrated nitric acid or concentrated sulfuric acid for a long time.

Alkali resistanceSince the ester group on polyester macromolecule is easily hydrolyzed by the action of alkali. At room temperature with concentrated alkali, high temperature with dilute alkali can make fiber destruction, only at low temperature to dilute alkali or weak alkali is more stable.

Solvent resistancePolyester has strong resistance to general non-polar organic solvents, even to polar organic solvents at room temperature. For example, soaking in acetone, chloroform, toluene, trichloroethylene, carbon tetrachloride at room temperature for 24h, the fiber strength does not decrease. In the heated state, polyester can be dissolved in phenol, dimethyl phenol, o-dichlorophenol, benzyl alcohol, nitrobenzene and phenol - carbon tetrachloride, phenol - chloroform, phenol - toluene and other mixed solvents.

ColorPolyester is generally milky white and with a mercerization, the production of non-glossy products need to add matting agent TiO2 before spinning, the production of pure white products need to add whitening agent, the production of colored silk need to add pigments or dyes in the spinning melt.

Surface and cross-sectional shapeConventional polyester has smooth surface and nearly circular cross-section. If the use of shaped spinnerets, can be made into a special cross-sectional shape of the fiber, such as triangular, Y-shaped, hollow and other shaped cross-sectional silk.

DensityPolyester has a density of 1.333g/cm3 when fully amorphous. 1.455g/cm3 when fully crystallized Usually polyester has a high crystallinity with a density of 1.38~1.40g/cm3, similar to wool (1.32g/cm3).

Rehumidification rate
(Water repellent property)Standard state polyester moisture regain rate of 0.4%, lower than acrylic (1% ~ 2%) and nylon (4%). Polyester's moisture absorption is low, so its wet strength drop less, fabric washability is good; but processing and wearing static electricity phenomenon is serious, fabric breathability and moisture absorption is poor.