The element technology items which are necessary to improve the functionality of the mold are the runnerless-system, filling of rubber into a decompressed mold, the cassette-mold, the flashless-mold, the heating method of the mold, the mold surface which prevents deposition from sticking, the washing of the mold, the automatic mold release of the cast, and others.
The main technical points that we should aim at in future are as follows:
· The complete runnerless-system which is made no runner to leave.
· High level molding in the vacuum by transferring its function to the molding machine.
· The switching for cassette-mold applications from all function collection design to a function differentiation design.
· The expansion of the object of the flashless-molding to the complicated shape products and larger products.
· The effective mold heating method by the three-dimensional placement of the heat source or electromagnetic induction.
· Lowering of energy of the mold surface that deposition prevents from sticking.
· The use of dry washing method without damage to the mold surface.
· The direct mold release method of the cast in the complete runnerless-system that cannot catch a runner.

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Rubber molds are widely used in the rubber industries, and the mold staining has been an important subject for a long time. This review describes the identification of the causes of mold staining, improvement of mold staining, mold releasing agent, and the washing methods of stained mold. Especially, improvements of anti-staining has been introduced by means of techniques related to rubber, various compounding ingredients, such as new material in place of zinc oxide, mold materials and the surface treatment of mold, such as coating of ceramics, nano-composite, fluoro resin and modification by ion. It has been confirmed that the suitable surface of stainless mold is obtained with increased flatness and larger contact angle of water. Various washing methods are introduced.

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The performances of metal mold will influence the properties and cost of rubber products.
Generally, the metal mold design for rubber products is more difficult than those for plastics because the rubber materials show the characterictic flow properties and curing behavior in mold cavities.
These fundamental rubber properties, such as flow properties, pressure loss and stress relaxation, are considered in order to design the metal mold, especially of vent hole, runner, gates structure, and gate layout.
At present these mold design technology has not been completely established yet. From now on, these study should be continued to elucidate more details.

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Troubles mean the generation of defective products in the compression moulding. The generation of defective products is considered to result from the flow and the scorch characteristics of mixed compound. These characteristics are dependent on processing temperatures. Watching the flow state when mixed compound goes into mould cavities is important. Other causes, such as parallel accuracy and distribution of temperature of platens, staining of mould, are related to defective products. This paper considers the causes and measures against defective products.

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