Challenge:
The main challenge was to achieve stable three-shot molding while meeting two different appearance requirements on the same part. The transparent area required an optical texture with high clarity and a consistent light-transmitting effect, while the black area needed a strong 3D textured appearance with clear grain definition and good visual depth. During molding, it was necessary to control the positioning and bonding of the three shots, while avoiding defects such as flow marks, mismatch, poor texture replication, weld lines, gloss inconsistency, and deformation. The difference in material behavior and surface requirements between the transparent and black areas made process control more difficult.
Solution:
We optimized the three-shot mold structure and injection sequence to ensure accurate positioning and stable bonding between different materials. For the transparent area, the cavity surface and processing parameters were carefully controlled to ensure precise replication of the optical texture and maintain good transparency. For the black area, the mold texture and molding conditions were optimized to achieve a sharp and visually dimensional grain effect. At the same time, the gate layout, cooling system, and molding parameters were adjusted to improve filling balance, reduce surface defects, and ensure stable appearance quality across both the transparent and black regions.
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