The Numerical Simulation And Experimental Research Of 'Layer Multiplier'

Polymer composite material always plays an very important role in our daily and production life. With the appearance of new polymer materials, and the increasing demand of polymer product performances, individual component products sometimes have limitation, it will not economically have satisfying using, exterior appearance and processing function. As the result, newly processing technology for multi-component composite products is developing quickly.In plastic industry, about 40% materials will be processed by extrusion and the enter market. Yet, extrusion even plays leading role in processing multiplayer film. Wherefore, comprehensive application area and huge market chance, urge each extrusion product line supplier continuously researching new technology. Researching of different structural composite material, technology or special market demand, require us to comprehend traditional extrusion product line. Meanwhile, maybe exploit extrusion industry fire-new application area.My task is based on American EDI extrusion die corporation's'Layer multiplier'technology, designed and processed smaller extrusion die with particular runner. And then used this die to process and do some experimental analysis of multi-component composite material:Firstly, summarize the development and current situation about multi-layer coextrusion technology in and abroad, even minutely elaborate the theory and structure of it. Summarize the researching harvest of predecessor, importantly introduce EDI's'Layer multiplier'technology and theory.Secondly, owing to the complicated runner structure, melt plastic flow is also complicated, meanwhile, plastic melt has special viscosity. We must calculate this problem with hydrokinetics theory. In this research, we choose Polyflow software to complete the simulation of the runner. We put forward that, the theory thickness ratio of the mould is 0.997:1:0.999:1.006, while the actually experimental thickness ratio is 0.972:1:0,003:1.010. So, this mould has high simulation accuracy and application.Thirdly, we design the layer-multiplier and cascading device mould, and then manufacture them according to the structure design. The difficulty lies in manufacturing multiplier's channels, requiring a higher precision, so we use wire cutting bed to process. As the flow channel constituted by the large angle shaped hole, we design the special tools, use the'two-step quadratic cut method', and optimize the processing parameters, at last, we complete processing it.At last, according to the theoretical result (velocity field, pressure field, etc), we do a series of experiments with existing equipment and current instruments. And then, indicate which processing factors will impact quality of multilayer composite material. In addition, we have some try to do some new material experiment. In addition, we processed the foamed and unfoamed multi-layer sheet. The mechanical performance test show that, we get a composite material of lower density, elastic modulus and strength was not declining, but the ductility increased by about 31 times. In the dispersion experiments, two layer composite material of PPR/Nano-CaCO3 (8% mass fraction), compares with composite material of a layer of PPR, another of PPR /Nano-CaCO3 (16% mass fraction), the elastic modulus increased by 16.87%, 17.28% improved strength, ductility decreased 7.43%,9.36% increase impact strength.