CAE-based Optimizing Design Of Injection Mold For Double-colored Monitor Shell

With the improvement of people’s living standard and the continuous progress ofscience and technology, people for the design of consumer products and use ofperformance requirements more and more high. Therefore, double color injection is aspecial method of plastic molding, two kinds of material or different color material bytwo independent injection unit of an injection molding machine passing through thenozzle into the mod cavity to form a single piece of plastic. Its molding product hasbeautiful appearance, good structural strength, stable quality, etc. Widely used in homeappliances, automobile industry and etc. Under the premise of a molding, double colorinjection mold save the insert or encapsulation molding process, and short cycleautomation production, resolve the defects of poor appearance and longcycle and lowefficiency of the traditional overmold injection molding from the fundamental, hasgreatly increased the production efficiency and save the cost.At present, as a kind of advanced molding process, double color injectionmolding technology is at the starting stage in China, the use of advanced computersimulation and optimization is rarely mentioned, the content of this paper is throughthe use of CAD/CAE technology to optimize the parameter of injection moldingprocess and injection mould structure, forming a high quality double color liquidcrystal television front shell at the last.LCD TV double color front shell as an example to research, according to thecoated structure of a two-component cover, two-component injection molding machinewith rotary plane was adopted to molding it. According to the structural characteristicsof plastic parts and high requirements of appearance quality, use the way of movingand stationary mode flip, the ejection mechanism will be set against the side of fixedmold. Using hot runner gating system at outer and inner layer, and use the needle valve gate. The first injection not only won’t leave gate scar, has no effect on the secondinjection, and has good fiuidity, the surface of products with giossy. Based on the flowanalysis of Moldflow, the gate location was optimized firstly, to determine the bestgate number and location. Double color front shell quality not only depends on theouter or inner quality, but depends on the two plastic molding adhesive interactionsituation, therefore, using thermoplastic overlapping injection simulation analysis,while viewing the two injection analysis results at the same time, check the plasticparts have no short, shrinkage potential defects, and the temperature impact of the twoinjection molding process, the maximum volumetric shrinkage of the outer and innerlayer. For the problems arising from the overlapping parts in thermoplastic injectionmolding, adopt the method of orthogonal experiment and the simulation analysis，select the influence factors and factor levels, make the sink index and ejection volumeshrinkage as the experimental index, optimize the injection molding processparameters. By range analysis method to determine the main controlling factors andinfluence degree, to get the optimal process parameters, and experimental verificationwas carried out. Last, design the overall structure of the plastic mold by Pro/Esoftware.