Asahi Kasei Chemicals has developed a very high flow rate (250 g/10 min) thermoplastic vulcanizate (TPV) with good mechanical properties. Called “Sunvieo”, the new material can be injection molded as a cost-effective replacement for PVC in an instrument panel skin.
Use of the material in the 2014 Nissan Sentra compact car won the “Most Innovative Use of Plastics” award in the 43rd Society of Plastics Engineers (SPE) Automotive Innovation Awards program. Using the specially formulated compound, Nissan supplier Calsonic Kansei Corp. molded a 1-mm skin with deep draws and uneven undercuts without tearing, creating new styling potential.
Molded in a 60-second cycle, the new skin material is 25 percent lighter and 10 percent less expensive than PVC slush molding and also reduced tooling costs. And the newest metric: There is a 58 percent carbon dioxide savings compared to PVC slush molding since the process is less energy intensive. The skin’s good mold-release characteristics reduce the need for mold-release spray, cutting volatile organic compounds.
Another win: There is an improvement in cycle times over slush molding or thermoforming of 14-80 percent.
“One of the technical requirements–the 1mm (0.040 inch) thickness of the IP skin–is possible today, but only with costly and sophisticated tooling technology,” said Yukinori Nakajima, TPV technical manager for Asahi Kasei Chemicals. “Unfortunately, these types of resources are not readily accessible in every country in which OEMs conduct manufacturing. But what if we were able to reframe the problem? If the solution lay in a higher technology material, now your only limit is having access to an injection-molding machine large enough to produce a bumper. “
Sunvieo–with a specific gravity of 0.90 g/cm3— is highly cross-linked, creating the necessary softness.