Research On Flash Of Injection Molded Plank Parts Based On Numerical Simulation

Injection molding, an importantpolymer processing method, is suitable forproducing plastic products with complex shape and highaccuracy.With plasticswidely usage and people’s living levelincreasing, the processingqualities,includingappearance, properties and so on, attract more attention whichhasbecome an important research topic in the field of plastic molding.During injection molding process, polymer melt flow into the mold cavitystructure associated with the parting line gap, putting pores, inserts gapor sliderclearance and other parts. Themelt overflow from the mold parting surface, and pingap to form flash. The flash directly affect the structure and performance of plasticparts,removing the flash may leave traces on the surface of the product and affect theappearance of products, even lead to waste. Now more research focus on the flashformingfactors, flashsolutions and thelength of flash, rather thanflash predictionbased on numerical simulations.In this paper, the flash numerical simulation flow hasbeen made. The main contents of this article are as follows.(1)Reviewed the reference articles and gave a summary ofthe role of CAEtechnology in injection molding defects prediction, such as the defectscauses,locations and quantity of defects.(2)The flash analysis flowchart was built with numerical simulations.With cavitypressure as the starting point,numerical simulations were performed to predict flashwhich was one of processing defects. Considering the effects of clamping force,differential processing pressure and cavity deformation, the flash index was built.And the possible regions of the flash were detected based on numerical results.(3) Numerical simulations of injection molded plank parts and IC card sets wereperformed to predict flash. Clamping forcewereanalyzed after meshing by hypermesh,pressure on product edge nodewerecalculated and deformation of the moldcavitywereresearched through the Moldflow and ANSYS coupled, then we couldpredict the location of flash on products. (4) Numerical simulations were performed to analyze the state of the melt flowat the end of the filling after flash mesh on parting surface built. By comparing theexperimental and simulation results, accuracy of numerical simulationswere verified.(5) Optimized the molding process and mold structure to improve the flash. TheIC card sets of molds structure was built by Pro/E. Combined with years of practicalexperience, the plug-breaking method was proposed to improve flash of hole insidethe IC card sets, which could be widely used in practical production.