The modern world depends heavily on products made of plastic, and most of them are created using injection molding processes. Everything from auto parts to milk cartons are now formed this way. Manufacturers meet product demands by sending their employees to specialty injection molding classes, where they learn to understand and use the processes. Although their education is often customized to meet specific job needs, all courses cover basic information that includes:
HOW INJECTION MOLDING STARTED
Polymers were introduced by Jon Jacob Berzelius as early as 1847, and Alexander Parkes exhibited man-made plastics at an International exhibition in 1862. Early material was expensive, flammable, and cracked easily. A version of today’s injection molding was developed by John Wesley Hyatt, an inventor who injected plastic through a heated cylinder into a mold. Early plastics were used to create buttons, collar stays, and combs. By World War II advanced technology was producing colored plastics, and by the 1970’s hollow molds were being used to create complex designs.
WHAT IT IS
Modern plastic products are created from molds that are designed by experts. Many materials are used, including glass, elastomers, metal, and thermoplastic polymers. Materials are fed into heated barrels, and then mixed and forced into mold cavities. Today’s complex molds are precision machined, often from aluminum or steel. When molded materials cool, they harden into the shape of the desired products. Recent advances have resulted in 3D printing of molds. The process incorporates photopolymer plastics that do not melt during injection.
HOW IT IS USED
Manufacturers create thousands molded plastic items that include packaging, auto dashboards, bottles, musical instruments, and furniture. Car bumpers may be made from durable plastic. Mechanical gears, storage containers, and wheeled bins are created using the process. Injection molding is used to create CD and DVD cases, phones, battery casings, toys, kits, and much more.
Injection molding is a process that forces heated materials into molds, to create a wide range of products. Modern molds are complex and materials have been adapted for thousands of uses. As a result, manufacturers often send workers to specialty classes, where they learn to understand the process and how to use it to create specific results.