Steve Ham shares his specialized knowledge of injection molded structural plastics processes and their application; gained during a career that started in 1973.
Development of large-part low-pressure injection molding started with the structural foam process decades ago and evolved. Counter pressure and co-injection were early adaptations to improve surface finish. Gas assisted injection molding emerged as a method to produce large thin walled pieces with thicker structural ribs.
Many specialized technologies have been developed in recent years including External Gas Molding. With a properly designed mold, a cushion of gas is injected between the mold cavity and the plastic surface. Volumetric resin shrinkage is contained to the core side of the molding while holding appearance surface packed against the mold cavity. The process works quite well with counter-pressure and thermal cycling filling techniques. Explore webpage overviews of these technologies. Navigate from the “Plastics” category tabs.
This website was first published in 2000, making basic reference material available at no cost. The material may be reproduced with proper credit. Steve Ham is available as a consultant to industry to help with design and manufacture of products utilizing advanced injection molding processes.
Much of this website is devoted to Steve’s other interests. You are welcome to explore car stories, antique clocks, aviation history and more from the “Personal” category tabs. Enjoy………