Extrusion method of super high molecular weight polyethylene nearby melting point

Abstract

The invention discloses an extrusion method of ultra high molecular weight polyethylene (UHMWPE) nearby melting point, which can fundamentally maintain the invariable molecular weight of extrusive materiel. The method comprises the steps that UHMWPE materiel with the molecular weight larger than or equal to 2 million is loaded into an extruder, and is extruded by the extruder after being conveyed, compacted and heated; during the heating process, the temperature of the materiel is controlled to ensure the temperature of the materiel to be lower than the melting point of the material and higher than 90 percent of the melting point, so as to ensure the material to be flowed in a solid phase and not to be degraded during the extruding process, therefore the fundamental invariable molecular weight of extrusive materiel is maintained, and the superior properties of the UHMWPE, such as the impact resistance, the pressure resistance and the frost resistance, are maintained after the materielis melted, shaped and cooled to be produced into the finished product in a mould.

Description

technical field [0001] The invention relates to an extrusion method of ultra-high-molecular-weight polyethylene for producing plastic products such as various pipes, plates, and profiled materials by using ultra-high-molecular-weight polyethylene as a raw material. Background technique [0002] Ultra-high molecular weight polyethylene (UHMWPE) is a thermoplastic with extremely high molecular weight. Compared with many polymer materials, it has a small friction coefficient, low wear, chemical resistance, impact resistance, pressure resistance, and frost resistance. , thermal insulation, self-lubricating, anti-fouling, stress cracking resistance, good sanitation and other outstanding features. These excellent properties make the friction coefficient of UHMWPE pipes very small, showing extremely high self-lubrication and anti-fouling properties, which can significantly save energy consumption in pipeline transportation, and its abrasion resistance ranks first among plastics, ma...

AI Technical Summary

Problems solved by technology

However, this kind of doping will also greatly reduce the inherent excellent characteristics of ultra-high molecular weight polyethylene, and the addition of these substances will cause the flow orientation of polyethylene ultra-macromolecules along the extrusion direction due to the "solvation" effect during the extrusion process. The ultra-high molecular weight polyethylene extruded from the extruder is fed into the mold, where it is melted, shaped, and cooled to form the final product. If the final product is a pipe, it will cause the pipe to rotate in both axial and hoop directions. The stress difference is very obvious, which affects the quality of the pipe. If the plate or profile is processed, it will cause serious deformation of the product