Twin shot moulding is a specialized injection moulding process that uses two different materials or plastics with distinct properties in a single mould. The materials are injected twice to produce composite components. This process enables the combination of different materials or functions in one step and is widely used in the manufacture of plastic parts that require different functions, hardness, colours, or textures.
First Injection: The first material is injected into the mould. This step typically forms the base structure of the component, which could be made from hard plastics or materials with specific properties (e.g., heat resistance, impact resistance, etc.).
Mould Transfer/Flipping: After the first injection, the mould is rotated or flipped to position the mould cavity for the second injection, ensuring proper alignment and contact between the two materials.
Second Injection: The second material, typically a plastic with different physical properties or colour (e.g., soft plastic, elastic material, or different coloured plastics), is then injected into the mould. This injection forms the second material over the first, bonding the two materials tightly.
Cooling and Ejection: After the injection is complete, the mould cools, and the part is ejected, forming a composite product with multiple physical properties or colours.
Multi-functional Material Combination
Twin shot moulding can combine different types of plastic materials, such as hard and soft plastics, transparent and opaque plastics, etc. It is commonly used to produce products with different physical properties, such as combining flexibility and hardness, anti-slip, sealing, and protective shells.
Improved Production Efficiency
With a single mould, two different materials can be processed simultaneously, eliminating the need for secondary processing steps (such as spraying, bonding, or assembly), thereby improving production efficiency.
Enhanced Product Aesthetics and Functionality
Twin shot moulding allows for dual-colour or multi-colour designs, enhancing the appearance and market competitiveness of products. For example, mobile phone cases, home appliances, and automotive interior components often use this technology for personalized design.
Cost Savings
Twin shot moulding enables the formation of different materials or colours in the same mould, reducing the need for multiple moulds or processing steps. This not only reduces material waste but also increases automation in the production process.
Stable Product Quality
Twin shot moulding ensures seamless bonding between the two materials, with high precision in material alignment during the moulding process. This reduces the occurrence of defects in the final product and improves consistency in product quality.
