As part of mold base and materials procurement process,the various types of materials must also be selected.Just as there are many different plastics suitable for injection molding,there are many ferrous and non-ferrous metals that are suitable for use in injection molds.
Some of the more common metals and their properties are provided in Appendix B.Of all these metals,AISI P20 is the most common due to its favorable combination of properties.However,P20 is sometimes improperly specified in many molding applications since other metals would provide better performance,lower mold making cost,or lower injection molding costs.
Mold base Sizing
The size of the mold base is determined primarily by the area required to accommodate the designed cavity layout.A primary issue, however,is the potential for conflict between the placements of the cavities and other mold components(such as leader pins,guide bushings,and others).Furthermore,there is the potential for conflict between cavity support systems(such as cooling lines,ejector pins,support pillars,etc.)and other mold components(such as leader pins,guide bushings,and others.)Due to these conflicts, mold bases are often sized larger than what would first be considered.
Parting plane for bezel
For the laptop bezel, the parting line can be radiated outward to form the parting surface. it can be observed that all of the out of plane feature along the parting line now become complex surfaces on the parting plane. These surfaces pose two significant issues during mold operation.First,any misalignment between the sharp features on core and cavity inserts will cause wear between the sliding surfaces if not an outright impact between the leading edge of the core and the mating cavity surface.