Process characteristics of plastic injection molds
Author：admin Date: 2023-08-20
Injection molding, a widely-used manufacturing process, involves the use of a ram or screw-type plunger to force molten plastic or rubber material into a mold cavity. This material then solidifies, taking the shape of the mold. The process is commonly used for both thermoplastic and thermosetting polymers, although thermoplastics are more frequently used due to their advantageous characteristics.
One of the primary benefits of using thermoplastics in injection molding is their ease of recycling. Unlike thermosetting polymers, which undergo irreversible chemical reactions when heated and cannot be recycled, thermoplastics can be melted and reprocessed multiple times without any loss in properties. This not only makes thermoplastics more cost-effective but also supports sustainability efforts.
The versatility of thermoplastics is another key advantage. They are available in a wide range of types and grades, each offering unique properties such as strength, flexibility, transparency, or flame resistance. This allows for the production of a diverse array of products using injection molding, including consumer goods, automotive parts, medical devices, and packaging materials.
Thermoplastics possess the ability to soften and flow upon heating, which is essential for the injection molding process. The plastic material is melted and injected into the mold under high pressure, ensuring it completely fills the mold cavity and takes on its desired shape. Once cooled, the material solidifies, retaining the shape of the mold cavity with high accuracy and detail. This enables the production of complex and intricate parts with tight tolerances.
In terms of safety, thermoplastics have an advantage over thermosetting polymers in the injection molding process. If a thermosetting polymer remains in the injection barrel for an extended period, chemical crosslinking can occur, causing the screw and check valves to seize.