Inkbit said its new elastomer can be used to replace or prototype soft rubber components, silicones, or molded TPUs that require precision and detailed features.

MEDFORD, Mass.—At the recent Formnext  2023 trade show, additive manufacturing company Inkbitintroduced a new soft-medium durometer elastomer that is reported to be an excellent choice for replacing or prototyping soft rubber components, silicones, or molded TPUs that require precision and detailed features.

In a release from Formnext, Inkbit described TEPU™ 50A as a thiol-ene polyurethane-based elastomer that has a Shore 50A durometer and low compression set. The latest addition to the Inkbit Vista™ ecosystem, TEPU 50A is said to provide excellent UV stability and strong chemical compatibility.

“TEPU 50A is the culmination of years of chemistry and process development driven by customers searching for an alternative to molded or cast silicones and rubbers for prototyping and beyond,” said Inkbit Co-Founder and CEO Davide Marini, in a statement. “Our novel thiol-ene polyurethane-based chemistries enable us to print soft but resilient elastomers that are UV stable and have excellent chemical compatibility.”

Inkbit said it developed TEPU 50A in response to “customer requests for a Shore 45-55A elastomer that could accurately produce intricate detail in a wide range of geometries with excellent surface finish and elastic resilience.” It is the second elastomer to be offered by Inkbit and follows TEPU 30A, formally known as the Vulcan Soft Elastomer 30.

According to Inkbit, TEPU 50A is “ideal” for demanding applications that require a medium-soft shore hardness and optimal sealing and compression attributes. It is said to be suited for applications like grommets, window and door seals, soft grippers, gaskets, and similar soft elastic components.

Inkbit said the new elastomer is not only a response to technical specifications; it also addresses real-world challenges faced by manufacturers when sourcing low-volume rubber-like components.

“Sourcing low-volume rubber-like components is a constant challenge for organizations,” said Maximilian Neck, CEO of 3D printing specialist ProductionToGo, in the release. “Traditional methods are expensive in small quantities and can take several weeks or months to procure, directly impacting overall production timelines. Before TEPU 50A, we couldn’t find a soft 3D printed elastomer option that combined good surface finish accuracy, fine detail reproduction, and stable mechanical properties to mimic nitrile rubber or molded TPU. We are excited about having this option available.”

TEPU 50A’s part properties are said to be highly stable due to a powerful thiol-ene chemical reaction during the print process. In addition, Inkbit’s unique Vision Control Jetting (VCJ) with closed-loop feedback control ensures that parts are built quickly and accurately every time, the company said.

When it developed TEPU 50A, Inkbit said it targeted properties similar to those found in nitrile rubber and silicone applications in automotive, as well as in other industrial applications where flexibility, sealing, and surface quality were critical. Key attributes in TEPU 50A are reported to include 7.7% compression strength set (23°C, 72 h); 49A Shore hardness; and 128 percent elongation at break.

Additional attributes include -28°C glass transition temperature (DSC-Tg);  9.4 percent change in elongation at break after 1,000 hours of UV aging; and 0.3 percent  weight gain after five days submerged in engine oil, the company said.