Reducing the carbon footprint of vehicles with the NRC's SNAP Composites industrial R&D group
- Boucherville, Quebec
The transition to cleaner energy sources in the transportation industry in order to achieve net-zero emissions targets has proven to be a major technological challenge for all players in the supply chain. These new targets have led manufacturers to find new ways to improve vehicle design and production processes, including reducing their weight, known as vehicle lightweighting. Weight reduction is critical not only for the impact on fuel consumption but also to compensate for the additional weight created by new propulsion systems, such as electric batteries.
One of the solutions available to the industry for reducing the carbon footprint of vehicles is to use composite materials to build lighter, safer and more energy-efficient vehicles. As the name suggests, composites are created from a combination of materials, including polymers reinforced with fibres of different physical and chemical properties that act as one to increase vehicle strength, stiffness and durability. Once these high-performance thermoset composites are processed using a specific compression manufacturing method, they can be formed into any shape and provide numerous advantages. For example, the composites require less maintenance because they don't rust or corrode. In terms of the production process, using composite materials reduces assembly time and costs because, unlike metals and alloys, their great design flexibility creates structural components with fewer pieces and allows for fewer production steps.
However, because of the complexity of traditional manufacturing processes for thermoset composites components, the transportation industry has faced technical and financial issues when it comes to adopting these processes and material for their applications.
SNAP-ing to success
To address these challenges and help the industry take advantage of composite lightweighting solutions, in 2019, experts in advanced polymer composites from the National Research Council of Canada's Automotive and Surface Transportation Research Centre launched a new industrial R&D group called SNAP Composites (a name chosen to evoke the need for "short novel affordable processes" for composite manufacturing). This 3-year collaborative initiative brought together 10 companies from all sectors of the ground transportation supply chain and 2 academic collaborators to develop a rapid and low-cost manufacturing process of advanced thermoset composites for vehicle parts. Funding for this initiative was provided by PRIMA Québec and the Natural Sciences and Engineering Research Council of Canada (NSERC).
The group's goal was to find a flexible and innovative solution suitable for all parts of the transportation sector, from automobiles to heavy trucks. To do so, it evaluated and developed 3 different manufacturing processes:
Resin transfer molding (RTM) compression moulding (SNAP–RTM)
Prepreg-compression moulding (SNAP–PREG)
All 3 methods use highly reactive thermoset resins to rapidly manufacture integrated structural composite parts with a cycle time of less than 10 minutes. Each method is based on a compression moulding approach. For SNAP–RTM, this involves injecting and compressing liquid thermoset resins within dry reinforcements, while for SNAP–PREG, it involves consolidating low cost prepregs. For SNAP–HYBRID, it involves combining prepregs and discontinuous local reinforcements.
The SNAP Composites group used these 3 processes to successfully test and create a prototype part for coach buses for group member Prevost, a Canadian manufacturer of motor coaches and bus shells and part of the Volvo Group. The work covered all aspects of the development cycle, from material selection and characterization, design and simulation to manufacturing and performance evaluation. The results led to a composite vehicle part 35% lighter than the original metallic one. The group was also able to manufacture a 1-piece composite structural component with a very complex geometry and large dimension, in a process cycle time of 5 to 10 minutes.
According to Nathalie Legros, Program Leader at Polymer and Composite Products Manufacturing for the Automotive and Surface Transportation Research Centre, designing and manufacturing a lightweight composite prototype for Prevost's electric coach buses has been a collective effort made possible thanks to the contribution of all the partners involved. "Our industrial partners provided materials and design space as well as invaluable input throughout the project that directly addressed their needs and requirements. Our academic partners, McGill University and Centre technologique en aérospatiale, provided expertise that complemented ours," adds Legros.
The project was completed in December 2022, and Prevost is now testing the prototype at its facility. If the tests perform well, the company is eager to take the technology to the next level. "It is sometimes hard to imagine the result at the beginning, but in the end, it's great to see that we can make a difference by collaborating on R&D projects," says Alexandre Leger, Product Engineer at Prevost.
"The hard work of the National Research Council of Canada team combined with the important contribution of each partner made this project a real success, namely by reducing the risks associated with developing and adopting these manufacturing methods," says Leger. "The technology demonstrator manufactured during the project, once characterized, could be implemented in our new line of long-distance passenger coaches."