| Double Injection produce variety colors, good handling feel, anti-water, anti-dust, anti-vibration components. It is widely using in handler, home appliances, communication products, automotive industry and so on. If Double Injection process be used in right way, it given high productivity, low scrap rate, reliable quality etc. The disadvantage for Double Injection is the processing needed special plastic injection machine, and the tooling/molding costly, and it is hard to capture the processes and technique, so far it is not common use for the moment.In this thesis, the following research carried out and the corresponding conclusions are as follows:1. Therefore, the existing second soft plastic injection of multi-material injection process, analysis and determine of mold design, which use the normal injection molding machine, could produce variety colors, good handling feel, anti-water, anti-duct, anti-vibration components. And the molding/tooling cost pretty low, short tooling fabrication time, it is widely use in urgency cases, and mass production requirement, it is equivalent as cost reduction and higher value for the products, and result to get higher competition for the company indirectly. Combine actual production, The article solved those major defect of second soft plastic injection of multi-material and injection processes, it's the guideline for corporation.2. The analysis of this article, is study current process and major defect of process conditional, especially the product stress characteristic.3. Analysis of the engineering plastics injection molding soft in the 2nd Molding injection molding defect, such as stress cracking, warping deformation, the high Reject rate in 2nd Molding waste injection and so on.4. The author analyzes the causes of products defective defects, primarily through the mold design and Select the appropriate injection molding parameters to control of products defects.5. The author conducted a mold design and injection molding process simulation, to achieve the purpose of this paper to solve defects of plastic products, access to the qualified products. |