Reactive Molding processes, also called thermoset molding processes, use thermoset materials.
- Characteristics of thermosets
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- chemical reaction during the molding process.
- cross-linked polymer structure.
- simultaneous polymerization and shaping during the molding process.
- Reactive processes
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- Reaction Injection Molding (RIM)
- Structural Reaction Injection Molding (SRIM)
- Resin Transfer Molding for fiber reinforced plastic (RTM)
- Multiple barrel reactive molding (RIM-MBI)
- Thermoset injection molding
- Rubber compound injection molding
- Microchip Encapsulation
- Underfill Encapsulation
- Advantages of reactive molding
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- 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.
The reactive molding analyses are integrated with the Autodesk material database, which offers more than 50 grades of lab-tested reactive molding materials. Specifically, Autodesk Moldflow Insight's Reactive Molding analyses can:
- Predict the melt front pattern to aid in part design and gate placement to optimize cavity filling for most reactive processes.
- Calculate the conversion (extent of cure) versus time at any location within the mold during filling and post-filling.
- Determine injection pressure and clamp force requirements for proper molding machine selection.
- Display injection pressure at any point within the cavity at any time during the filling stage.
- Graphically display the temperature change as a result of the reaction kinetics inside the mold at any point in time.
- Detect short shots due to pre-gelation conditions.
- Accurately identify weld (knit) lines based on part design and gate placement.
- Accurately identify air traps for proper mold venting.
- For RTM and SRIM analyses: allow users to define multiple anisotropic fiber mats with different orientations in the cavity.
- For reactive molding and microchip encapsulation analyses, predict part warpage.1