Short fibers are short-length natural fibers and cut chemical fibers. The cut chemical fibers can be further divided into cotton fibers, wool fibers, and medium-length fibers.

Generally, the length of the cotton fiber is 33-38 mm, the length of the wool fiber is 76 mm or more, and the length of the medium-length fiber is 51-66 mm.

Polypropylene staple fiber, also known as PP fiber or polypropylene. The polypropylene staplet fiber is made of polypropylene raw material and is processed by a one-step short-spinning process.

Characteristics and uses of polypropylene staple fiber

Relative Density: Polypropylene is a relatively low density of all synthetic fibers, about 0.91 g/cm3, so it is lighter in weight and can cover a larger area per unit weight of fiber.

Strength: The strength of polypropylene is similar to that of high-strength polyester fiber and nylon in synthetic fiber, but the strength does not change in wet state, which is better than nylon.

Abrasion resistance and corrosion resistance: The flatness of polypropylene is second only to nylon, but it is slightly less resistant to sharpening. Corrosion resistance: Significant stability to inorganic acids and bases.

Hygroscopicity and dyeability: Polypropylene is almost non-hygroscopic, its moisture regain is less than 0.03%, the fabric shrinkage rate is small, and fine-denier polypropylene has a strong wicking effect. The dyeing fastness is poor, and ordinary fuel can not be dyed. Most of the colored polypropylene is produced by pre-spinning coloring.

Electrical insulation and thermal insulation: polypropylene has high electrical resistivity (7×10 Ω.cm) and low thermal conductivity. Compared with other chemical fibers, polypropylene has good electrical insulation and thermal insulation, but it is easy to generate static electricity during processing.

Heat resistance and aging resistance: Polypropylene has a low melting point (165~173°C) and poor stability to light and heat. Therefore, polypropylene has poor heat resistance and aging resistance and is not resistant to ironing. However, it is possible to improve the anti-aging property by adding an anti-aging agent at the time of spinning.

In addition, polypropylene, like other synthetic fibers, is less prone to mold, rot, and not afraid of insects.