Magna tests Canadian fibers for eco-friendly car parts

Target applications for ConceroTM could include interior parts like the glove box, center console and instrument panel, among others. Source: Magna International

Mark Willliamson

The company's ConceroTM wood fiber and plastic composite is now being tried out in production-scale compounding and molding equipment at its automotive part plants.

The extra market potential for long fibers is music to the ears of pulp producers.

Not all new bio-fiber products require the trendy nano or micro scale cellulose to be revolutionary. On the contrary, there is still room for ground-breaking applications for wood cellulose using good old-fashioned macro-scale fibers that we in the industry are so familiar with. In fact, long fibers as they come from the pulp mill are being modified now to work in manufacturing equipment that are far removed from the paper industry. The objective is to produce reformulated end-use products – often displacing non-renewable ingredients - that exhibit equivalent or superior physical properties, are lighter and may cost less. Magna International is getting closer to achieving these laudable objectives. The extra market potential for long fibers in Magna's development of eco-friendly car parts is music to the ears of pulp producers.

Magna is now proceeding with factory production testing and verification of its new Concero trademarked wood fiber polymer composite for injection molded automotive part applications. These lighter weight and eco-friendly car parts are the result of a research and development program spanning about 2.5 years in collaboration with the National Research Council of Canada (NRC) and the Alberta Innovates Technology Futures (AITF) research organization in Edmonton, Alberta. AITF conducted the fiber characterization of pulp fibers from many different mills across Canada. The fiber processing and compounding development and pilot machine testing was done at the Magna-NRC Composites Centre of Excellence in suburban Toronto. The research effort is supported by the Centre for Research and Innovation in the Bioeconomy (CRIBE) and Alberta Innovates Biosolutions (AIBIO), investment arms of the Ontario and Alberta provincial governments respectively, and the Ontario BioAuto Council, a not-for-profit auto parts industry funding group which closed operations early in 2014.

The results of the program so far were described by Dr. Alex Baltazar, Magna's project lead at a recent Society of Plastics Engineers Automotive Engineered Polyolefins Conference in suburban Detroit. That's a clear-cut automotive industry audience hearing about the potential of wood fiber - an fascinating potential, to be sure! All fiber types evaluated were commercially available from a variety of pulp mills, including Kraft, TMP and BCTMP mills and included hardwood and softwood species from across Canada. The expertise development for fiber modification, fiber and polypropylene compounding and processing into finished products was a significant part of the effort required. Thus, pulp producers supplied a standard product.

The lightweight part development has been driven by regulations to reduce gasoline consumption and carbon dioxide emissions. Recyclability at the end of a part's lifecycle is also a major factor as the industry aims for 85% recovery. And, of course, the sustainability of parts manufacturing using a renewably sourced material that is not part of the food chain is a significant objective for manufacturers and consumers.

Body parts targeted

With the new wood fiber polypropylene composite Magna is targeting the replacement of parts currently made from 20% glass fiber-reinforced polypropylene. Automobile body parts comprise almost 40% of a typical vehicle's weight so substituting some those parts with a lower cost and lighter weight renewably sourced alternative is a logical way to get the most leverage for total vehicle weight reduction. Typical interior applications could be glove boxes, door parts, pillars, and consoles, among others.

Wood fibers offer advantages in final product density (hence weight), cost, production energy input and functional properties. For instance, wood fibers embedded in a polymer matrix offer improved stiffness and toughness if the fibers are long enough. Wood fiber aspect ratio and diameter can be altered and fiber surfaces can be modified to bond within the polymer matrix to give the required properties for the application. This modification is a key to the process development accomplished during the program.

Body parts comprise almost 40% of a vehicle's weight. Source: A2Mac1
Lower density, lower cost

Wood fiber and polypropylene composites have a lot going for them and have multiple advantages over glass fiber reinforced polypropylene, as explained by Dr. Baltazar in his presentation. Wood fibers are approximately 40 % lower in density and up to 50% lower in cost compared to traditional glass fibers. Finished product testing revealed that a wood fiber composite showed a significant improvement in tensile and flexular modulus over the benchmark product, with similar sub-zero temperature impact resistance. Dispersion of the fiber in the plastic matrix was also excellent, thus providing good physical properties and avoiding molding process problems like nozzle plugging.

Volatile organic compounds emitted by the fiber were kept in check by a special technique developed by Magna. Other properties like fogging, durability, aesthetics, flammability, odor, and service temperature were as good as the benchmark. Different fiber types imparted different physical characteristics and therefore could be matched to the application. For instance, in some products the visual appearance was important so the fiber type could be selected to achieve the right color.

One step closer

To wrap up his presentation Dr. Baltazar estimated the potential size of the market for wood fiber and lignocellulosic fiber-reinforced polymer molded parts. He calculated that in a typical automobile about 14 kg of cellulose fiber-reinforced composites could be deployed. Based on the historical production of 60 million vehicles per year worldwide, that would mean a consumption of close to 800,000 tonnes of composite per year with a cellulose fiber fraction between 20 to 40 %. That could be more if the projected global production of 87 million vehicles for 2014 is considered.

The move to production-scale testing signals that commercial products in automobiles are getting one step closer. The acceptance by auto manufacturers will be watched eagerly by pulp producers that naturally want another outlet for their fibers to bolster their profitability. Once market accepted, Magna could use these fibers in their plants. The company has manufacturing plants in North and South America, Western and Eastern Europe, Asia and Southern Africa.

Concero composites have been tested in Magna's production-scale injection molding processes like this. Source: Magna International
This article is based on a publication in Bio-Fibre Magazine, November, 2014