Speciality chemical company Lanxess is working with 3D printing firms to provide the next generation of Low Free (LF) isocyanate urethane prepolymers that can be formulated into resins for 3D printing. These high-performance resins, based on Adiprene LF pPDI (para-phenylene diisocyanate) prepolymers, are easy to process and safe for industrial manufacturers as well as for the casual home, office or retail user, the company said.

The footwear industry is a key user of 3D printing technology for the midsole, upper, and structural components such as heels and toes. Footwear components are designed to require both very soft and more rigid elastomers. The wide flexibility to formulate LF prepolymers into printable resins enables 3D printers to drive toward mass customisation, enabling printing across a wide range of hardness from very soft elastomers for cushioning to the more structural shoe elements.

Adiprene LF pPDI prepolymers are designed to provide superior resistance to low and high temperatures, excellent toughness, and superior resistance to chemicals and abrasion. With excellent property retention up to six weeks at 150 °C, athletic shoes, for example, can be stored in a hot car for long time periods without losses. In addition, footwear components benefit from higher flexural fatigue resistance and cold temperature flex performance down to – 20 °C.

LANXESS offers urethane prepolymers for 3D printing with other chemistries, including LF MDI and LF HDI. High-performance LF pPDI prepolymers can be designed with lower viscosity for easier processing and higher productivity. Adiprene LF pPDI prepolymers contain less than 0.1% residual isocyanate, reducing the hazard classifications and protecting users from potential exposure.