Design of in-mold decoration mold for complex thin-walled parts

Abstract

In order to address the issues of warping deformation and long-term production of complex thin-walled parts during In-Mold Decoration (IMD) production, the structure design of the IMD mold was carried out with the humidifier top cover as the production object. To ensure the flow characteristics of molten plastic in the mold during the injection molding process, based on the technical contradiction analysis of TRIZ theory, the hot runner mold is improved to mix cold and hot runner, that is, the sprue is set as a hot runner, the branch runner is set as a cold runner, and use a multi-point injection cold gate solution. And construct a complex structure numbering method to arrange and design various complex structure undercut-forming side insert mechanism, design of special structure lifters along the same direction of motion the two inverted buckle at the same time undercut-forming. The lifter mechanisms are used to complete the molding, parting, demolding and ejection of plastic parts, multiple uses for one mechanism. In order to optimize product quality and improve production efficiency, providing theoretical and empirical support for the production of complex thin walled parts with IMD molds. Then design the cooling system and demolding mechanism separately. Finally, based on Moldflow software, the final flow of plastic part warpage analyzed. The maximum warping deformation of the product is 0.7055mm, while the maximum warping deformation of the traditional cold runner mold is 0.8519mm, reducing the warping deformation of the humidifier top cover.

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