Injection Molding
Injection molding involves injecting molten composite material into a closed mold at high pressure. The process typically uses thermoplastic resins reinforced with chopped glass fibers. The material is heated to temperatures between 200°C and 300°C and then injected into the mold at pressures ranging from 50 MPa to 200 MPa, depending on the material and part complexity. The mold is kept cool, allowing the part to solidify quickly before being ejected.
The fiber content in injection-molded parts typically ranges from 10% to 50%, and the cycle times can be as short as 30 seconds, making the process ideal for mass production. The molds used in injection molding are usually made of tool steel, with tolerances as tight as ±0.05 mm for high-precision parts.
Injection molding is capable of producing complex parts with excellent repeatability and tight dimensional tolerances. The parts generally exhibit good mechanical properties, with tensile strengths of up to 150 MPa and flexural strengths around 250 MPa, depending on the fiber content. Additionally, injection molding allows for rapid production rates, making it cost-effective for high-volume manufacturing.
Injection molding is commonly used in the automotive industry for producing parts like dashboard components, engine covers, and under-the-hood applications that require high heat resistance (up to 150°C). The electronics industry uses injection-molded housings and enclosures due to their good thermal and electrical insulation properties (typically with breakdown voltages up to 20 kV). Medical devices and consumer products like packaging and appliance housings are also commonly manufactured using this method
