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Increasing the quality as well as the economic efficiency of thermoplastic parts by coating the surface of the mould

Objective



The objective of this project is the developent and optimization of coating.processes to increase the quality of thermoplastic injection molded parts. Another aim is to improve the economic efficiency of the injection process. In most cases, the most important quality characteristic is the surface quality of the molded part. In order to achieve a good reproduction of the mold surface and to avoid defects such as visible weld lines, high contact temperatures between the mold wall and the plastic melt are needed. In common injection processes such temperatures can only be obtained by meuns high mold wall temperatures, which in turn strongly increase the cycle times and thus reduce the econimic efficiency of the process. Previous experiments have shown that the optical characteristics can be clearly improved by short high contact temperatures. Inside the injection mold this shall be achieved by using suitable coatings as insulation layers. For this, the heat penetration ability of the laminate has to be extremely low. In addition, other properties of the mold surface, such as low wear, topography of the mold surface, heat resistance, elasticity, low tendendy to stick to the plastic, etc. have to be guaranteed. After analyzing the actual status, laminates with the above described characteristics are developed in cooperation with the coating companies. Experimental molds are coated with the different processes and corresponding laminates and are then tested in the K.l.M.W. test center.The first tests include the optical characteristics, the demolding behavior with different types of plastics as well as the economic efficiency. In paralles, the physical laminate characteristics needed for the calculation of the contact emperature, are determined. Afterwards, long-term investigations to evaluate the tool life behavior are necessary. Sorftware to simulate the contact temperatures for different plastics with different mold surfaces, is to be developed.

Funding Scheme

EAW - Exploratory awards

Coordinator

Mauer Metallurgische Verfahrenstechnik GmbH
Address
24 A,kränkelsweg 24 A
41748 Viersen
Germany