1.Polyester Fiber  

 Polyester staple fiber is made of polyester (ie polyethylene terephthalate)

Referred to as PET, polymerized from PTA and MEG), it is re-spun into a fiber obtained by cutting the tow. PET is in the form of rice grains or flakes, and the variety and color are different. (The main ingredient of the beverage bottle that we usually touch is polyester. It is sliced. Generally, the two main processes of pre-spinning and post-spinning can produce polyester short. Fiber, according to different needs, in the post-spinning can be cut into different specifications of polyester staple fiber, generally 4D-22D, according to its curl can be divided into two-dimensional and three-dimensional two). 75% is used for polyester for chemical fiber, and polyester staple fiber and polyester filament are manufactured according to the requirements of the textile industry.

When it is close to the flame, it melts. When it comes into contact with the flame, it melts and burns and emits black smoke. When it leaves the flame, it continues to burn. Sometimes it kills itself. It has a sweet taste when burned. The residue after cooling is hard and black.

Strength: The strength of polyester fiber is nearly 1 times higher than cotton and 3 times higher than wool, so polyester fabric is durable.

Heat resistance: It can be used at 70 to 170 ° C, which is the best heat resistance and thermal stability in general-purpose fibers.

Elasticity: The elasticity of polyester is close to wool, the wrinkle resistance is higher than other fibers, the fabric is not wrinkled, and the maintenance is good.

Wear resistance: Polyester's wear resistance is second only to nylon, ranking second in synthetic fiber.

Water absorption: Polyester has low moisture absorption rate and good insulation performance, but due to low water absorption, static electricity generated by friction is large and dyeing performance is poor.

2.Acrylic Fiber（Polyacrylonitrile fiber）

Acrylic fiber, which is obtained by copolymerization of a first monomer of 100% acrylonitrile by wet or dry spinning. Melting when approaching the flame, melting and burning when exposed to flame, burning and black smoke when leaving the flame, burning hair when burning, residue after cooling broken.

(1) Morphology: its longitudinal surface or a small number of grooves, the cross section varies with the spinning method, the dry-spun fiber cross-section is dumbbell-shaped, and the wet-spinning is round.

(2)Stretchability and elasticity: Its strength is 17.6~30.8cN/tex, which is lower than polyester and nylon. Its elongation at break is 25%~46%, similar to polyester and nylon. Acrylic fiber is fluffy, curly and soft, and has good elasticity, but the residual deformation of multiple stretching is large, and the fabric has poor shape retention.

(3) Hygroscopicity: Acrylic fiber has a compact structure and low hygroscopicity. Under normal atmospheric conditions, the moisture regain is about 2%.

(4) Light resistance: Acrylic fiber is particularly excellent in light resistance and weather resistance, and is the best among common textile fibers. Acrylic fiber is exposed to outdoor exposure for one year, and its strength is only reduced by 20%. Therefore, acrylic fiber is most suitable for outdoor fabrics.

(5) Acid and alkali resistance: It has good chemical stability, acid resistance, weak alkali resistance, oxidation resistance and organic solvents. However, the acrylic fiber will yellow in the lye and the macromolecule will break.

(6) Other properties It has good heat resistance, but has poor wear resistance and poor dimensional stability. Acrylic fiber has a relatively low density.