| Aiming at the current problems are confronted with plastic industry and plastic injection molding: (1) indexes for plastic quality control, such as melt index, can't correspond with process parameters directly or indirectly, so they can't be effectively employed to guide injection molding mold design, process design and part design; ( 2 ) the theoretic study on rheologic properties of plastic can't match practical produce well, in some aspects, much need to be done still, for example, the experiential checkingformula for melt flow ratio(X) in injection mold is /l = ^Z.,/f, , the influences ofhorizontal section and figure of channel and injection system on melt flow ratio are not taken into account, it is introduced that based on melt fluidity test molds, and two kind of representative plastics polypropylene(PP) and polyethylene(PE) are used as experiment materials, relations between melt flow ratio and characters of channel horizontal section and figure are researched by experiment and test. Results can be used to guide the optimization design of injection molding mold, process and part.Following universal principles of mold design, a series of melt fluidity test molds with different characters of channel horizontal section and figure are designed and manufactured economically. These melt fluidity test molds can completely and factually simulate the conditions in molds used in produce. Rules of plastic melt flow ratio are achieved for the first time. At the same time, flow model of melt is founded, simulation software C-MOLD is employed to aid the analysis of results of experiment and test. Based on experiment , test and theory analysis, correctional checking formulas formelt flow ratio( A ) in injection mold, , areobtained by introducing correctional coefficients a and The research about channel will apply with injection system too. Melt fluidity test molds, methods and results of research can be generalized to test the properties of materials and the development of parts and materials for other moldable materials, such as thermoplastic, thermoset, metal powder, ceramics, and so on. |
