3M worked closely with automakers on some recent hybrid programs, including Toyota’s Prius and Auris and Honda's CR-Z. Now the technology company plans to bring its expertise and specially developed versions of Thinsulate material to Europe via its recently formed European Automotive Acoustics Group.
“The early adopters buying these cars expect hybrids to provide an efficient, premium driving experience with superior refinement,” said the head of the new group, Abs Master. “Balancing the weight and performance of the car’s acoustic package…requires lightweight materials optimized to manage the higher range of frequencies.”
He noted that 3M’s Thinsulate can effectively absorb the higher-frequency sounds produced by hybrid vehicles’ electric motors and transmissions. The material is said to be lightweight, compact, and compressible for ease of packaging and assembly.
3M was reluctant to provide specifics about the specially developed material since Thinsulate is not patent-protected and there are some trade secrets in the manufacturing process. Thinsulate is a mix of polypropylene, which provides the high-frequency noise absorption, and polyester, which makes the material compressible.
“Standard Thinsulate was a very good starting point and so development was really a process of fine-tuning the material for the application,” a company spokesman told SAE Magazines. “For the hybrid grade, 3M does one or two clever things with the polypropylene content to fine-tune its high-frequency noise absorption.”
The company expects the material solution to be particularly useful for vehicles that are based on platforms for which a hybrid version was not originally planned.
The original Prius was the first hybrid to use the material.
Applications of Thinsulate have included door panels, headliners, wheel wells, pillars, and instrument panels. For hybrids, it is used in the same locations but also can be applied around hybrid-specific parts such as electric motors, power electronics, etc.
The material replaces mixed-fiber shoddy mats, foams, and absorbers, reducing the weight of some acoustic-material parts by up to 40%, or “several kilos,” the company claims.
“It’s more cost-effective rather than lower-cost,” the spokesman said. “It depends on the application to an extent. If a vehicle has been modified to run as a hybrid, it is considerably less expensive than redeveloping the acoustics package using conventional sound-deadening materials. Because Thinsulate is also easier to attach and requires less packaging space, it is often more cost-effective than trying to work with conventional materials. You need a lot of shoddy to mask high-frequency noises.”
Thinsulate comes die-cut with slits so that it can fold and conform easily around the contours of the vehicle.
The material is available in the U.S., and 3M is already in talks with U.S. manufacturers, according to the spokesman.
Other transportation sectors are suitable outlets for the material as well, with current applications in off-highway and commercial vehicles.
“Its thermal insulation properties are making it an attractive option for applications such as lining cabin walls,” the spokesman said. “New regulations that stop drivers from idling their engines to heat the interior at night make this a growing issue for the industry.”
3M also has a range of acoustic solutions for aerospace and is reportedly talking to companies about applications in which Thinsulate could be used to absorb high-frequency noises.