Stiff as PP: nucleator for HDPE significantly increases resin properties

• Nucleating agent with special crystalline orientation
• Up to 50% increased stiffness vs. standard HDPE
• Applications: material handling (waste containers, totes, crates, pallets)

At the recent Pack Expo International, Milliken & Company introduced a new nucleating agent for injection molded high-density polyethylene (HDPE). Featuring a special crystalline orientation, Hyperform HPN 210 M improves the mechanical performance of HDPE to levels approaching those of polypropylene (PP) impact copolymers. The new additive, which specifically targets material handling applications such as waste containers, totes, crates and pallets, is the first in a range of next-generation nucleators that Milliken is developing.

Up to 50% increased stiffness vs. standard HDPE

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. Furthermore, 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 increases heat distortion temperatures by 10-40°C, as determined by the ASTM D648-07 test.

Easier processing and shorter cooling times

In addition, the nucleator further improves the processing of HDPE, including higher productivity due to shorter cooling times. The ability to create lamellar crystal orientation of PE in the polymer flow (or machine) direction aids the reduction in shrinkage. Control of shrinkage and warpage contributes to an improvement in the overall quality of large, complex parts, opening the window for PE to become a potential material of choice in molds that traditionally run PP, without the need to re-tool.