Research On The Effect Of Conformal Cooling On Injection Molding Part Warpage

Because of technical limitations of injection mold manufacturing, traditionalmold cooling system usually consists of straight cooling channels (TCC), whenmolding some irregular shape plastic parts, there will occurs many deficiencies. Withthe advances in3D printing technology, it promote the development of conformalcooling technology, the manufacturing of conformal cooling channels (CCC)becomes more efficient, and the practical application of CCC also receive more andmore widespread attention. In this paper, make the thin-walled plastic pots andtransparent automobile headlights lens as two injection molding analysis case. Twodifferent structures of CCC were designed by the method of dividing the cooling zone,then comparison with the original design of TCC respectively. The channels structureof CCC in thin-walled plastic pots injection mold are likes a double-helix shape, andchannels structure of CCC in automobile headlights lens injection mold are someconformal curved pipes that close to the cavity surface. Combined the heat transfertheory of mold and the deformation mechanism of parts warpage in injection molding,by use of CAE software ANSYS and Moldflow to analyzed the mold transientcooling process and the quality of products, finally obtain the results of percentagefrozen layer changes over time, mold surface temperature histories in the process ofthe injection mold reach a steady state from start-up, temperature distribution ofcavity and core surface, coolitant temperature changes in cooling channels and theparts warpage results.The results shows that, CCC can not only shorten the molding cycle time, butalso can reduces the warpage of injection molding products. Compared with the TCC,the use of CCC in thin-walled plastic pots mold shortened injection molding cycletime by nearly44%, and a more uniform cavity surface temperature distributionoccurred on the side area of plastic pot, the average temperature of cavity and coresurface became lower, so the cooling efficiency and the warpage deformation causedby unevenness mold cooling were greatly improved. Compared the results of thecooling water temperature changes on TCC and CCC can evaluate the reasonableness of the cooling channels design. The injection molding cycle time of automobileheadlights lens was shortened by about37.7%. The transient thermal analysis on theprocess of the injection mold to reach a steady state from an initial state through anumber of injection molding cycle shows that the CCC can regulation the moldtemperature more quickly and reduced the number of cycles to reach a steady state.Due to the structure of CCC conformed to the shape of the injection mold cavity andcore surface outline, so that the temperature on one side of the cavity or core surfacebecame more uniform, while the difference of temperature between the cavity andcore surface is also significantly reduced, thereby it makes a great reduction on thewarpage deformation of automobile headlights lens.