Injection Molding Examples:
- Custom plastic injection molding
- 40-1,600 ton molding machines
- Engineering + design capabilities
- CAD/CAM + in-house tooling
- All secondaries + assemblies
50g (2oz) to about 25kg
Injection molding is a process in which a polymer is heated to a highly plastic state and forced to flow under high pressure into a mold cavity, where it solidifies. The molded part, called a molding, is then removed from the cavity. The process produces discrete components that are almost always net shape. The production cycle time is typically in the range of 10-30 seconds, although cycles of one minute or longer are not uncommon. Also the mold may contain more than one cavity; so that multiple moldings are produced in each cycle.
Complex and intricate shapes are possible with injection molding. The challenge in these cases is to design and fabricate a mold whose cavity is the same geometry as the part and which also allows for part removal. Part size can range from about 50g (2oz) up to about 25kg (more than 50lb), the upper limit represented by components such as refrigerator doors and automobile bumpers. The mold determines the part shape and size and is the special tooling in injection molding. For large complex parts, the mold can cost hundreds of thousands of dollars. For small parts, the mold can be built to contain multiple cavities, also making the mold expensive. Thus, injection molding is economical only for large production quantities.
Injection molding is the most widely used molding process for thermoplastics. Some thermosets and elastomers are injection molded, with modifications in equipment and operating parameters to allow for cross-linking of these materials.
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