A composite fiber is described that is capable of forming various fiber cross section shapes with high accuracy and maintaining high dimensional stability of a cross section shape. Also provided is a method for producing the composite fiber, the method comprising: distributing a sea-component polymer and at least one other-component polymer different from the sea-component polymer; discharging the sea-component polymer and the other-component polymer distributed by the distribution plate respectively from sea-component discharge holes and other-component discharge holes of a discharge plate positioned at a downstream side of the distribution plate with respect to a polymer spinning path direction; and discharging the composite polymer from a discharge hole of a spinneret discharge plate positioned at a downstream side of the discharge plate with respect to the polymer spinning path direction.

A process prepares a monofilament by a) melt-spinning a thermoplastic polyurethane and forming a monofilament; b) cooling the monofilament under a temperature of 0 C. to 40 C.; c) stretching the monofilament by at least two groups of rollers; d) heat-setting the monofilament; and e) winding the monofilament. The thermoplastic polyurethane has a Shore hardness of no less than 65D measured according to DIN ISO 7619-1. The monofilament prepared from the process is also described.

A process prepares a monofilament by a) melt-spinning a thermoplastic polyurethane and forming a monofilament; b) cooling the monofilament under a temperature of 0 C. to 40 C.; c) stretching the monofilament by at least two groups of rollers; d) heat-setting the monofilament; and e) winding the monofilament. The thermoplastic polyurethane has a Shore hardness of no less than 65D measured according to DIN ISO 7619-1. The monofilament prepared from the process is also described.

Provided are a polymer foamed fiber and a preparation method thereof. The polymer foamed fiber has a closed-pore structure in an interior, the closed-pore structure comprises uniform and dense pores and an average pore size of the pores in the closed-pore structure is in a range of from 1 m to 50 m. The polymer foamed fiber has a diameter in a range of from 0.08 mm to 1.0 mm with an average deviation of the diameter of 0.05 mm, a skin layer thickness in a range of from 0 to 0.1 mm, a density in a range of from 0.30 g/cm.sup.3 to 0.90 g/cm.sup.3, and an elongation at break in a range of from 0 to 600%. The polymer foamed fiber has advantages, such as, light weight, uniform fiber thickness, a porous structure, dense internal pores with uniform pore sizes and a controllable skin layer thickness.

Provided are a polymer foamed fiber and a preparation method thereof. The polymer foamed fiber has a closed-pore structure in an interior, the closed-pore structure comprises uniform and dense pores and an average pore size of the pores in the closed-pore structure is in a range of from 1 m to 50 m. The polymer foamed fiber has a diameter in a range of from 0.08 mm to 1.0 mm with an average deviation of the diameter of 0.05 mm, a skin layer thickness in a range of from 0 to 0.1 mm, a density in a range of from 0.30 g/cm.sup.3 to 0.90 g/cm.sup.3, and an elongation at break in a range of from 0 to 600%. The polymer foamed fiber has advantages, such as, light weight, uniform fiber thickness, a porous structure, dense internal pores with uniform pore sizes and a controllable skin layer thickness.

A method for manufacturing an electret melt blown nonwoven fabric, wherein, when a non-electroconductive polymer is melt-spun from a spinneret having a plurality of spinning holes in the width direction and a spun yarn is collected by a yarn collection device provided below to form a melt blown nonwoven fabric, water is sprayed by a spray nozzle to the spun yarn between the spinneret and the yarn collection device to electretize the melt blown nonwoven fabric, the spray nozzle includes a plurality of water discharge openings arranged in the width direction and a pair of air discharge openings that are opened continuously or intermittently in the width direction and arranged to face each other, and air discharged from the air discharge openings is made to collide with water discharged from the plurality of water discharge openings to spray the water on the spun yarn.

A method of preparing an antibacterial anti-yellowing ZnO antimony-free polyester fiber is provided. In direct spinning of antimony-free polyester melt, an anti-yellowing nano antibacterial agent is introduced into a polymerization process of antimony-free polyester to obtain the antibacterial anti-yellowing ZnO antimony-free polyester fiber; the anti-yellowing nano antibacterial agent is a surface-deposited or coated nano ZnO of a phosphate ester small molecule having a function of resisting thermal oxidative degradation, the phosphate ester small molecule is bound to the nano ZnO by van der Waals force, hydrogen bonding or covalent bonding, and the phosphate ester small molecule is a phosphate ester molecule with a molecular weight of less than 500 Da; the content of the nano ZnO in the antibacterial anti-yellowing ZnO antimony-free polyester fiber is not lower than 1.2 wt %, and the yellowing index Yi value of the antibacterial anti-yellowing ZnO antimony-free polyester fiber is not higher than 16.1.

The present disclosure provides a polyamide 5 staple fiber, a preparation method and use thereof. The polyamide 5 staple fiber has a denier of 8.0-30.0D, a breaking strength of 2.0-6.0 cN/dtex, and an elongation at break of 30-100%. The polyamide 5 staple fiber has good mechanical properties and softness, and a blended wool yarn for manufacturing carpets with good mechanical properties, dyeability, and wear resistance can be obtained by using the polyamide 5 staple fiber.

The present disclosure provides a polyamide 5 staple fiber, a preparation method and use thereof. The polyamide 5 staple fiber has a denier of 8.0-30.0D, a breaking strength of 2.0-6.0 cN/dtex, and an elongation at break of 30-100%. The polyamide 5 staple fiber has good mechanical properties and softness, and a blended wool yarn for manufacturing carpets with good mechanical properties, dyeability, and wear resistance can be obtained by using the polyamide 5 staple fiber.

The invention relates to a rubberized strength member for elastomeric products, especially vehicle tires, wherein the strength member includes at least one first yarn, to a process for producing the rubberized strength member and to a motor vehicle tire including at least one rubberized strength member. According to the invention, the first yarn is a yarn of HMLS-PET comprising recycled PET.