Research On Molding Technology Of Steel Reinforced Plastics Pipe

Steel reinforced plastics pipe has both the advantages of the steel pipe and the plastics pipe for its special structure, which solve the problems including withstanding pressure and easy corrosion of the steel pipe and also corrode resisting and not withstanding pressure of the plastics pipe, and this leads the direction of pipe's development to anticorrosion and withstanding pressure. The products of steel reinforced plastics pipe are mostly pipes and matching pipe fittings. Its processing method is the formation of recombination of HDPE with the formed steel skeleton, meanwhile, the producing process is fussy. The flow of the melt is complex, and the defects of forming appear easily, so it is necessary to make systematic research into the forming process of the products.Firstly, this paper, explores the extrusion molding technology and design guidelines of pipe in detail. Taking the Dn100 extrusion die as an example, the finite element model of the flow of melt in the Dn100 extrusion die is developed using the POLYFLOW software, and the effects of the inflow's flowing rate and the pulling speed on the flow of melt are researched. Combining the real producing situation, the optimum parameters are simulated and analyzed. The flow of melt is discussed, and the distributions of pressure, the speed, the shear rate and the Viscosity in the extrusion die are obtained.Secondly, the injection molding processing is deeply researched, the structure of the injection mold's design and its design guidelines are studied. Taking the pipe fittings–T-joint tube and straight fitting of the Dn65 pipe, the finite element model of the flow of melt is developed using the MOLDFLOW software. The flow of the melt, the cool and warp of the product are checked and investigated in the practical injection molding processing. The Fill Time, Temperature Distribution, Maximum Temperature(part), Warp etc. are obtained and the factors of the effect on the part's quality are analyzed.Finally, the simulation parameters are verified by the experiments, the scientificity of forming theory and the rationality of the principles of mold design are proved.