Reactive Molding processes, also called thermoset molding processes, use thermoset materials.
Thermosets, unlike thermoplastics, are characterized by the following:
- A chemical reaction during the molding process.
- A Cross-linked polymer structure.
- A Simultaneous polymerization and shaping during the molding process.
Processes
The Reactive Molding processes include the following:
- Reaction Injection Molding (RIM)
- Structural Reaction Injection Molding (SRIM)
- Resin Transfer Molding (RTM)
- Multiple-barrel reactive molding (RIM-MBI)
- Thermoset injection molding
- Rubber injection molding
- Microchip Encapsulation
- Underfill Encapsulation
Advantages
The Reactive Molding analysis offers the following advantages:
- Thermosets' cross-linked polymer structure generally imparts improved mechanical properties and greater heat and environmental resistance.
- Thermosets' typically low viscosity permits large and complex parts to be molded with relatively lower pressure and clamp force than required for thermoplastics molding.
- Thermosets can be used in composite processes. For example, RTM and SRIM processes, which use a preform made of long fibers, offer a way to make high-strength, low-volume, large parts. Fillers and reinforcing materials can enhance shrinkage control, chemical and shock resistance, electrical and thermal insulation, and/or reduce cost.