As part of the first method, a hydraulically operated piston, which is integrated in the movable side of the mold, is immersed in a specially provisioned and appropriately dosed melt cushion.
Alternatively, the equivalent melt volume is available on the stationary side of the mold in the hot runner. In this case, the molten material is pressed into the cavity using a needle-valve-like mechanism. Both methods are currently being tested and refined by DuPont, with a current emphasis on minimizing the additional space required.
"We have conducted numerous injection molding trials with different semi-crystalline thermoplastic grades at our Technical Center in Meyrin, Switzerland, and were able to demonstrate, on the basis of producing standard bars used for tensile testing, the potential efficiency improvements," said Ernst A. Poppe, European manager for application and processing technology at DuPont Performance Polymers. "IMHP technology is particularly beneficial when molding DuPont™ Delrin® acetal resin, for which the hold pressure time constitutes a large proportion of its overall cycle time. Additionally we were able to demonstrate that there were no significant changes in terms of dimensional stability and mechanical properties between standard injection-molded samples produced with IMHP technology."
DuPont Performance Polymers is committed to working with customers throughout the world to develop new products, components and systems that help reduce dependence on fossil fuels and protect people and the environment. With more than 40 manufacturing, development and research centers throughout the world, DuPont Performance Polymers uses the industry's broadest portfolio of plastics, elastomers, renewably sourced polymers, filaments and high-performance parts and shapes to deliver cost-effective solutions to customers in aerospace, automotive, consumer, electrical, electronic, industrial, sporting goods and other diversified industries.
DuPont (NYSE: DD) has been bringing world-class science and engineering to the global marketplace in the form of innovative products, materials, and services since 1802. The company believes that by collaborating with customers, governments, NGOs, and thought leaders we can help find solutions to such global challenges as providing enough healthy food for people everywhere, decreasing dependence on fossil fuels, and protecting life and the environment. For additional information about DuPont and its commitment to inclusive innovation, please visit http://www.dupont.com.