Injection molding process
production of resin matrix composites
suitable for thermoplastic and thermosetting composites, but thermoplastic composites are the most widely used
Principle of injection molding process
Based on the principle of metal die casting:
granular resin + short fiber => injection cavity
*heated and melted, mixed evenly, and injected into a closed mold with a lower temperature at a certain extrusion pressure => cool & shape => final product
Process: feeding, melting, mixing, injection, cooling hardening and demoulding
Point to note:
1) if the shape of the product is complex, it is easy to have uneven distribution of local fibers or a large number of resin enrichment areas, which will affect the performance of the material. Therefore, the injection molding process requires that the resin and short fiber are evenly mixed.
2) the mixing system has good fluidity, while the fiber content should not be too high, generally about 30% - 40%.
