Moldflow Analysis Based Optimization Design Of Injection Mold For Plastic Flip-top Lid

Plastic cap especially flip-top cap is an indispensable and important part of daily necessities.The flip-top lid is with the inside screw,hinge,thin wall,small,precise characteristics.For such complex mold,the traditional mold design usually meets a lot of problems.A comprehensive method is urgently needed for design and optimization,to avoid possible problems and shorten the development cycle of mold.Therefore,in this thesis,one method is raised to design mold like this,which proposes mold flow analysis and orthogonal decomposition,in-depth study of the injection mold design and optimization.Main work and results are as follows.The Flip-top lid mold was established and optimized.Based on the characteristics of mold of flip-top lid,parts accuracy requirements,functional requirements and appearance defects,two-dimensional and three-dimensional drawing of mold was designed,analyzed and optimized by software Pro/Engineer.The structure of the flip-top lid mold was optimized and parameters were adjusted,which shortened the traditional mold design and manufacturing process of trial and redesign,enhanced the generation efficiency,and reduced the production cost of mold.Moldflow was applied to do plastic flowing analysis and cooling analysis in injection stage,in parallel the defects including gas trips,welding line,warp,and shrinkage mark were discussed and optimized by Moldflow.Then Moldflow was used to optimize the structure of the mold and the parameters of injection.The mold structure was determined by the formula,according to two mold flow analysis,to get the optimization of the filling system and cooling system.The injection parameters were optimized.Based on the orthogonal decomposition method,the best process parameters were found to reduce the warpage of the plastic parts to the minimum without changing the structure of the flip-top lid mold,which is also the best solution to do the mass production.Finally,the results of the mold validation were compared with the Moldflow analysis results to find whether there are some gaps and get a solution.The key process parameters of injection mold were found and optimized based on multiple objects such as warpage and shrinkage by orthogonal decomposition and weighted average.The influence of different process parameters were identified on the warpage,shrinkage and deformation.A set of good practice was provided for the optimized design of Flip-top lid mold.