Chicago — After about 10 years of research and development, Milliken and Co. unveiled what it calls a "game changer" for injection molded high density polyethylene (HDPE) applications. This new technology, which Milliken introduced at Pack Expo (booth E-10513), features a unique crystalline orientation that reportedly improves the mechanical performance of HDPE to levels approaching those of polypropylene (PP) impact copolymers.

The Hyperform HPN 210 M nucleator gives molders new processing options for packaging and material handling applications.

Reed Walker, business development and marketing manager for Milliken's plastics additives business, told PlasticsToday that the new additive is targeting material handing applications such as waste containers, totes, crates and pallets. The Hyperform HPN 210 M enables an improvement in physical properties part quality and production. For instance, an unnucleated HDPE pallet tends to experience warpage, whereas the new nucleating agent will help reduce this issue.

Walker said that the control of warpage opens the window for PE to become a preferred material in molds that traditionally run with PP.

"The industry wants something like this," he said. "It will improve operations and it allows flexibility for future designs."

Testing done according to the American Society for Testing Materials (ASTM D790-00) showed increased stiffness (modulus) of up to 50 percent vs. standard HDPE. This stiffness can enable thinner-wall designs, contributing to weight reductions of the final part. Additionally, Hyperform HPN 210 M nucleating agent improves HDPE's heat resistance, enabling it to be molded into a wide range of products where PP is already commonly used. High-density polyethylene nucleated with the new Hyperform HPN 210 M additive boosts heat distortion temperatures by 10 - 40°C, as determined by the ASTM D648-07 test.

Milliken's Hyperform HPN 210 M nucleator further improves the processing benefits of HDPE, including higher productivity due to shorter cooling times, according to the company. The new nucleator's unique ability to create lamellar crystal orientation of PE in the polymer flow (or machine) direction aids the reduction in shrinkage.

The new nucleating agent will be available in the U.S. on Dec. 1, and subsequently in Asia, Latin America and Europe, pending chemical registrations. Food contact approvals are also in process.