| The plastics injecting products as one of the main structure parts of the modern industrial products, have already been widely used in a lot of fields of all trades and professions. Because of the complexity of forming process, the products of moulding are extremely apt to produce various kinds of defects, especially the existence of fusion line defect has universality. As one of the common appearance defects of injecting the products, it not only influences the appearance quality of the products, and make the electroplate process produce colour difference .It also produce an influence and damage on the mechanics performance of the products to the intensity of the products when being serious to make, bring the potential hazard to normal use of the products , influence products quality, arise from serious waste of material and energy ,etc. How to dispel or weaken the fusion line's defects which is formed in the moulding process and improve the quality of the products is one of the important subjects for research of the mold design and manufacturing field. This Subject combining some sort of car's safe bar realizes the multi-gate (or multi-sprue) sequence control system which is adopted adding configuration software to control hydraulic loop at the base of injection molding machine, make the part-material flow forward, mixed them altogher and realizes the aim to eliminate or restrain the happening of fusion line. 1. Summarizes the course of the injection moulding and the meaning of this dissertation. After having consulted much domestic and international materials about injection moulding. This dissertation introduces the injection moulding's development , the development trend in our country and foreign countries and the eliminating resolvent of fusion line at the present time. This dissertation still points out the simpleness and validity of eliminating fusion line with hot runner multi-gate sequence control. 2. Mould plastics and filling the course melting body rheology analysis of the mould Point out plastic fusibility belongs to the fluid which is glutinous, no-Newton and non-compressible. The fusibility has the flow course of free surface and non-isothermal instant state when it conduct the movement of fill-moulding. Depict simply the physical course of fusibility filling moulding. It is analysed that the spring when a melting body forward flows emerges alikly with " sandwich " phenomenon, make preparation for it is analysed that the mark of welding produces mechanisming. Utilize viscidity hydrodynamics and spread the basic equation of calorifics especially, is it that equation set up to fill by power rate mould melting body model is it is it is it is it flow dish and type flow rheology nature of course to become to melt to analyse to come function have to use. 3. A system of flowing and structure moulding plastics and relying on Introduce and flow a systematic classification and composition. Analyse thermal current dishes of system compare routine flow dishes of system pros and cons at the economy and technology. Point out a system of thermal current with its enormous advantages demonstrated while producing heat plasticity plastic products in enormous quantities of characteristic with good economy , with high automatic degree, especially already been in the important position in large-scale a production of moulding plastics. Have introduced the design principle of every part of thermal current in the structure and production of the thermal current one emphatically. Including flow the section of one is designed, flow long than question flowing dish assign form , runner , size and type person who choose direct relation of spray nozzle is it make pieces of several factors of quality to mould plastics. 4. The reason why fusion line is existing and the flow chart tool Analyse the reason and result why fusion line produces by effect of "sandwich"proved that fusion line is two different state of melting body flow each other material , energy exchange complete and different from melting and...
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