【正文】 any warping during the injection causes operating problems. Another important feature the plastic part has to have is a high bending stiffness. A number of feeders in different orientation were added to the part as shown in Figure 5b. These feeders should be designed in a way that it has to contribute the weight of the part as minimum as possible. Before the design of the mould, the flow analysis of the plastic part was carried out with Moldflow software to enable the selection of the best gate location Figure 6a. The figure indicates that the best point for the gate location is the middle feeder at the centre of the part. As the distortion and warpage of the part after injection was vital from the functionality point of view and it has to be kept at a minimum level, the same software was also utilised to yiled the warpage analysis. Figure 5 b shows the results implying the fact that the warpage well after injection remains within the predefined dimensional tolerances. 6. Conclusions In the plastic injection moulding, the CAD model of the plastic part obtained from mercial 3D programs could be used for the part performance and injection process analyses. With the aid of CEA technology and the use of concurrent engineering methodology, not only the injection mould can be designed and manufactured in a very short of period of time with a minimised cost but also all potential problems which may arise from part design, mould design and processing parameters could be eliminated at the very beginning of the mould design. These two tools help part designers and mould makers to develop a good product with a better delivery and faster tooling with less time and money. References 1. Smith P, Reinertsen D, The timetomarket race, In: Developing Products in Half the Time. New York, Van Nostrand Reinhold, pp. 3–13, 1991 J, The total product development organization. Proceedings of the Second Asia–Pacific Rapid Product Development Conference, Brisbane, 1996 R, Don’t stop after the prototype, Seventh International Conference on Rapid Prototyping, San Francisco, 1997 PF, “Chapter 3: Rapid Product Development” in Rapid Tooling: Technologies and Industrial Applications , Ed. Peter D. Hilton。 3. rationalisation of ponents (reducing assemblies)?！驹囊弧緾ONCURRENT DESIGN OF PLASTICS INJECTION MOULDS . A. YAYLA /. Pa? a YAYLAAbstract The plastic product manufacturing industry has been growing rapidly in recent years. One of the most popular processes for making plastic parts is injection moulding. The design of injection mould is critically important to product quality and efficient product processing. Mouldmaking panies, who wish to maintain the petitive edge, desire to shorten both design and manufacturing leading times of the by applying a systematic mould design process. The mould industry is an important support industry during the product development process, serving as an important link between the product designer and manufacturer. Product development has changed from the traditional serial process of design, followed by manufacture, to a more organized concurrent process where design and manufacture are considered at a very early stage of design. The concept of concurrent engineering (CE) is no longer new and yet it is still applicable and relevant in today’s manuf acturing environment. Team working spirit, management involvement, total design process and integration of IT tools are still the essence of CE. The application of The CE process to the design of an injection process involves the simultaneous consideration of plastic part design, mould design and injection moulding machine selection, production scheduling and cost as early as possible in the design stage. This paper presents the basic structure of an injection mould design. The basis of this system arises from an analysis of the injection mould design process for mould design panies. This injection mould design system covers both the mould design process and mould knowledge management. Finally the principle of concurrent engineering process is outlined and then its principle is applied to the design of a plastic injection mould. Keywords :Plastic injection mould design, Concurrent engineering, Computer aided engineering, Moulding conditions, Plastic injection moulding, Flow simulation 1. Introduction Injection moulds are always expensive to make, unfortunately without a mould it can not be possible ho have a moulded product. Every mould maker