Jing Wei, Senior Architecture Manager at Product R&D Division, Moldex3D

The multi-component molding (MCM) technology can efficiently integrate more than two separate plastic parts and is widely applied in the industry. Through CAE analysis, manufacturers can simulate product quality in advance. However, if we only consider the processing of the second shot, the product quality and design optimization cannot be ensured. Due to the effects of multiple injections and numerous materials, the part insert status at the end of the first shot will affect the part warpage behaviors in the second shot. Thus, we need to better control the effects of the previous shot on the part warpage.

How the Material Properties of Previous Shot Affects the Second Shot

The mechanical and thermal expansion properties of the materials are important factors that affect warpage behaviors. In the MCM process, the final product might be assembled from more than two materials. If the part insert in the second shot is made from fiber-reinforced plastics, its anisotropic properties will affect the final product’s deformation. Moreover, the part insert is from the previous shot, so the fiber orientation caused by the previous shot will be highly relevant to the second shot (Fig. 1).

Fig. 1 The fiber-reinforced plastics of the previous shot is used as the part insert of the second shot

How the Processing of the Previous Shot Affects the Second Shot

The mold design and processing conditions of the previous shot derived from the internal pressure and temperature states in the part insert of the previous shot. Thus, under the interactions between the different components, the initial status of the part insert will bring changes to the heat conduction and stress balance of the products. Thus, to ensure the final product quality, we also need to consider the manufacturing process of the previous shot (Fig. 2).

Fig. 2 The status of the second-shot part insert after the previous shot

To comprehensively consider the effects of the previous shot, Moldex3D can integrate the analysis results of the previous shot in the second shot simulation (Fig. 3). The Filling/Packing/Cooling and fiber orientation results of the previous shot can all be utilized in the second shot simulation. Thus, users can attain more accurate warpage analysis results.

Fig. 3 Integrating the analysis results of the previous shot in the second shot simulation

Through Moldex3D Warp analysis, users can import various effects and states including fiber orientation, temperature, and pressure of the previous shot into the second-shot part insert simulation. Therefore, the warpage analysis results can be more consistent with reality, and users can further optimize the product quality successfully through critical information.