This technical information has been contributed by
Piper Plastics

High Pressure Molding Technology Developed for Near Net Shape Plastics

CHANDLER, Ariz. — Piper Plastics (now Mitsubishi Chemical Corporation) has developed a proprietary high-pressure molding technology that is reported to yield near net shape polymers up to 2 inches thick without porosity, voids, or sinks. The process is suitable for larger parts and weights of up to 6 pounds per blank with large and varying wall thicknesses and complex geometries.

“This capability is especially beneficial for large CNC machined parts that were historically limited to extruded or compression molded stock shapes,” said Dave Wilkinson, materials engineering manager for Piper Plastics, in a company release. “In comparison to extrusion and compression molding, this new process yields parts that have higher strength—typically 15-20 percent stronger than extruded shapes, and 50 percent stronger than compression molded shapes—plus more consistent mechanical properties.”

The technology also allows Piper to offer small batch runs for mating the right polymer or blend for an application. “Distributors typically only carry about 50 types of engineering plastics, but with this technology, we can mold custom blanks from over 3,000 polymers and compounds, or develop a compound specifically for an application,” said Bruce White, vice president of Piper Plastics.

The process, which utilizes molding equipment designed and developed by Piper Plastics, allows the company to mold high performance thermoplastics, filled or unfilled, with isotropic mechanical properties. A major reason for developing the new technology was to save costs when machining finished parts from expensive high-performance materials, such as PEEK, PAI, or TPI.

“The molds are inexpensive since we are only molding a near net shape that will be machined after molding,” said White. “Because it’s close to the final part, a near net shape requires less machining. Less machining means less waste, which is an important consideration for green and sustainable programs.”

Mitsubishi Chemical Corporation (https://www.mcam.com/na-en/products/engineered-solutions/?r=1), a provider of high-performance polymer materials and precision machined components and assemblies, is a subsidiary of Quadrant Engineering Plastic Products.