Abstract: The present invention discloses a process for producing low-titer, high-strength and high-modulus polyethylene fibers, comprising the following steps: dissolving the ultra-high molecular weight polyethylene into paraffin oil with a low viscosity to form a spinning solution with a concentration of 3˜15%; extruding the spinning solution through a thin spinneret with at least 10 orifices having a diameter ? of 0.7˜0.8 mm and a length/diameter ratio of 10˜12, by applying a high pressure in the range of 2.5±1.0 MPa to the spinning solution, such that the fluid in the orifices is extruded at a shear rate of 200˜3 500 sec?1; and then performing a jet stretch at a deformation rate of 200˜5 000 min?1 within an air-gap of 10˜15 mm between the spinneret and the quench bath surface; feeding the jet-stretched fluid into the quench bath to form gel filaments; extracting and drying the gel filaments; and performing a multistage ultrahigh post stretch on the dried gel filaments with a stretch ratio of 15 or less.

Abstract: A stab and ballistic resistant material and method of preparing the same, comprising a stab-resistant layer and a ballistic resistant layer, wherein the stab-resistant layer comprises at least one layer, wherein each layer is constituted of two structural units, each of which is formed from perpendicularly combined high strength and high module unidirectional fiber prepreg strips, adjacent structural units are rotated 45°, and the stab-resistant layer has membranes adhered to both sides; the ballistic resistant layer comprises at least one layer, wherein each layer is constituted of two structural units, each of which is formed from perpendicularly combined unidirectional fiber prepreg strips, adjacent structural units are rotated 90°, and the ballistic resistant layer has membranes adhered to both sides. The stab and ballistic resistant material of the invention makes stab and ballistic resistant vests lighter, more efficient in protection, and easy to produce.

Abstract: A stab and ballistic resistant material, comprising a stab-resistant layer and a ballistic resistant layer, wherein the stab-resistant layer comprises at least one layer, wherein each layer is constituted of two units, each of which is formed from perpendicularly combined high strength and high module unidirectional fiber prepreg strips, adjacent units are combined with rotated 45°, and the stab-resistant layer has membranes adhered to both sides; the ballistic resistant layer comprises at least one layer, wherein each layer is constituted of two units, each of which is formed from perpendicularly combined unidirectional fiber prepreg strips, adjacent units are combined with rotated 90°, and the ballistic resistant layer has membranes adhered to both sides. The invention also provides a method for preparing the above stab and ballistic resistant material.

Abstract: The present invention discloses a process for producing low-titer, high-strength and high-modulus polyethylene fibers, comprising the following steps: dissolving the ultra-high molecular weight polyethylene into paraffin oil with a low viscosity to form a spinning solution with a concentration of 3˜15%; extruding the spinning solution through a thin spinneret with at least 10 orifices having a diameter ? of 0.7˜0.8 mm and a length/diameter ratio of 10˜12, by applying a high pressure in the range of 2.5±1.0 MPa to the spinning solution, such that the fluid in the orifices is extruded at a shear rate of 200˜3 500 sec?1; and then performing a jet stretch at a deformation rate of 200˜5 000 min?1 within an air-gap of 10˜15 mm between the spinneret and the quench bath surface; feeding the jet-stretched fluid into the quench bath to form gel filaments; extracting and drying the gel filaments; and performing a multistage ultrahigh post stretch on the dried gel filaments with a stretch ratio of 15 or less.