The Preparation And Performance Testing Of The Triple-layer Co-extrusion Polyolefin Material Composite Membrane

Due to a significant increase in demand for high-voltage level of insulationmaterials, insulating materials with high-performance has been requested.Therefore, to find a new type of cable insulation materials, or to improve thepreparation technology of the insulating material is particularly important. Thedevelopment of multi-layer co-extrusion technology provides a new way ofthinking for preparation of cable insulation materials. Selecting multilayer co-extrusion technology to the field of preparation of new cable insulation materialis expected to make up the shortcomings of the traditional flat vulcanizingmechanism, and can exactly simulate the cable insulation structure. Studying thisnew co-extrusion technology has an important significance whatever intheoretical basis or in the project application.Firstly, the polymer melt flow characteristics have been elaborated thoroughly,and the relevant parameters are obtained. On this basis, it is prepared formodeling and theoretical analysis. A detailed description of the design theory ofthree-layer co-extrusion head has been expounded. The key to design the head isselecting flow channel. Through comparison and analysis, we select the clothesrack type flow with multi-class flow advantages. In order to ensure the rationaldesign of the head, aiming at the melt flow properties in the head, a simulationanalysis has been made by using FLUENT. And observing the distribution of thesimulated velocity field and pressure field, a full validation for thereasonableness of head design has been made.According to the formed co-extrusion die and setting up the experimentalequipment of co-extrusion. Make reparation of three different materials forextrusion experiments, and observe its interface. According to the cable insulation structure, make preparation of semi-conductive-insulation-semi-conductive layer composite structure, and through tensile testing, SEM,conductivity and dielectric spectroscopy, compare with triple pressed insulatingmaterials, and make the corresponding analysis.