Envalior is introducing Durethan® FLX-RTM, a new impact-modified PA6 material that delivers excellent low‑temperature mechanical performance and is specifically engineered for rotational molding of tank liners, delivering excellent melt flow for complex geometries and exceptional mechanical performance. With rotational-molding specialist Elkamet, Dautphetal, Germany, the material has already been successfully processed into prototype tank liners.

By complimenting Envalior’s established materials for various liner‑production processes, Durethan® FLX‑RTM addresses the growing importance of rotational molding in tank manufacturing. Rotational molding offers a highly economical single‑stage process that produces homogeneous components—eliminating pinch‑off seams typical of extrusion blow‑molded liners and weld seams required in multi-part injection‑molded designs.

“Our heat‑stabilized compound offers high melt flowability for rotational molding, enabling precise formation of filigree screw‑thread areas or the integration of metal or aluminum boss parts. It also retains the strengths that characterize our Durethan® PA6 compounds for injection molding and extrusion blow molding,” explains Keestra.

Durethan® FLX‑RTM is a heat‑stabilized, impact‑modified, easy‑flow PA6 compound based on low‑molecular‑weight polyamide 6 with excellent flow properties. It maintains strong mechanical performance thanks to best‑in‑class impact‑modification systems and heat‑stabilization packages.

Key performance attributes include: Low hydrogen permeability, providing a high barrier against small gas molecules. Compatibility with liquid fuels, including CE10 gasoline and other apolar liquids. Exceptional toughness at temperatures down to –40 °C. High elongation and ductility. Combined, these properties support safe, durable liner solutions across a range of storage media and environmental conditions.

Together with Elkamet, a leading specialist in technical plastics with decades of experience in rotational molding, blow molding, and extrusion, Envalior has produced several prototype parts using electrically heated molds, vacuum assistance, and nitrogen purging to translate the material’s intrinsic properties into outstanding part performance.

Elkamet brings decades of experience in taking prototypes to series production and has deep expertise in hydrogen‑storage vessel manufacturing. The company supports customers in improving part design and optimizing mold construction for fast and efficient production.

Envalior and Elkamet support manufacturers with a comprehensive range of services throughout all stages of component development. This includes design, processing, and manufacturing expertise built over many years in plastic liners for high‑pressure tanks of various sizes, designs, and media.

A distinct advantage is Envalior’s comprehensive hydrogen‑permeation data, which few material suppliers provide. “With this data, customers can understand how permeation depends on pressure, temperature, and wall thickness, and optimize their liner design accordingly,” says Keestra. Envalior also provides detailed material data on mechanical behavior and processing properties and offers on‑site support for process optimization and series‑production startup.