Injection molding is the most effective process for the mass production of plastic parts. However, there are various plastic part surface defects which occur during the injection molding process. Sink marks are among the most difficult surface defects to improve. The sink marks usually appear as depressions on the surface of a molded part. These depressions are typically very small; however, they are often quite visible because they reflect light in different directions to the part. In this paper, we conducted experimental studies in order to minimize sink marks that occurred on the in-mold type PAB door seam line by using the Mucell injection process. The results of the study indicate this method can be used to eliminate sink marks using the Mucell injection molding process.

Equipments to influence by external force have to take effect mechanical oscillation. These equipments regardless of the movement on the external force such as roll, pitch and heave etc, worked to keep the height of tote are required for activeness and needed a device as equipment’s fluctuation for rapidly compensation. Because the actual development of these devices is difficult to cost-effectively, we were developed to compensation simulator scaled down 1/50. In this paper, we were studying kinematic characteristics, designed the simulator to grasp the point and manufactured. This paper was analyzed for confirming the superiority of compensation simulator and set up 50 ton crane in practice.

The characteristic of sheet metal process is the few loss of material during process, the short processing time and the excellent price and strength. The sheet metal process with above characteristic is common used in industrial field, but in order to analysis irregular field problems the reliable and economical analysis method is demanded. Finite element method is very effective method to simulate the forming processes with good prediction of the deformation behavior. Among Finite element method. the static-implicit finite element method is applied effectively to analyze real-size auto-body panel stamping processes. which include the forming stage. In this paper, it was focused on the drawing ability factors on auto-body panel stamping by AUTO FORM with using tool planning alloy to reduce law price as well as high precision from Design Optimization of die. According to this study, the results of simulation will give engineers good information to access the Design Optimization of die.

The AutoForm previously used the membrane element and it accomplished sheet metal forming analysis. The membrane analysis has been widely applied to various sheet metal forming processes because of its time effectiveness. However, it is well-known that the membrane analysis can not provide correct information for the processes which have considerable bending effects. In this research experimental results were compared with the analysis results obtained by using the shell element which is applied newly in the AutoForm commercial software. The shell element is a compromise element between continuum element and membrane element. The Finite element method by using shell element is the most efficient numerical method. From this research, it is known that FEA by using shell element can predict accurately the problems happened in actual experimental auto-body panel.

In rigid-plastic finite element method, there is a heavy computation time and convergence problem. In this study, static-explicit rigid-plastic finite element method will be introduced. This method is the way that restrict the convergence interval. It is expected that various results from the numerical analysis will give very useful information for the design of tools in sheet metal forming process.