Material improves design and space, exec says
TRAVERSE CITY, Mich. — Toyota Motor Corp. has added more in-house carbon fiber production capacity — and it’s not just for supercars and not just about cutting weight.
While the industry is wondering whether lightweight carbon fiber can become plentiful and affordable enough for automotive mass production, Toyota has begun producing a carbon fiber sheet molded compound in Japan for the liftgate on the Prius Prime plug-in hybrid.
The material is also being used for the doors and deck lid of the Lexus LC.
It is not only about weight reduction, a company executive told Plastics News, an affiliate of Automotive News, Monday at the CAR Management Briefing Seminars. Using carbon fiber sheet molded compound — referred to in the industry as SMC — means designers can improve package space in the Prius, even with additional room needed for batteries, said JP Flaharty, executive program manager for technical strategy at Toyota North America R&D.
The composite also enables Toyota to make narrower rear pillars, so drivers have an improved sight line.
“We’re looking for ways to benefit the customer that go beyond weight reduction,” Flaharty said. “It’s also about the structure and the way we’ve executed the car: better sight lines, better usability, better utility space.”
The parts represent a 40 to 50 percent weight reduction.
CF SMC is a new process for Toyota. The automaker has has used CF prepreg and resin transfer molding for its LFA supercar and high-performance variants of the Lexus IS and RC.
“Those are specialty use for those unique panels,” Flaharty said.
Working with material supplier Mitsubishi Chemical, the SMC process, with its chopped fibers rather than long fibers in prepreg and other processes, is both faster and has proved far easier for Toyota to bring in house, and in a mass market vehicle.
“The material we’re using is more similar in design and manufacturing conceptually to sheet metal forming,” Flaharty said. “You’re making a mold, you’re making a shape, it’s got this 3-D characteristic to it. So we’ve got a lot of know-how and a lot of understanding in how that works.
“We can align our capabilities to do this internally.”
Toyota assembles the Prius Prime at the Tsutsumi plant and the Lexus LC at the Motomachi plant, both near its headquarters in Toyota City, Japan.
