Automotive Bioplastics
Automotive Bioplastics in Automotive Applications First components are on the market, OEMs are evaluating and considering Flax 64,2% Hemp 9,5% Jute/Kenaf 11,2% Sisal 7,3% Other 7,9% source: nova-Institut Components of the Mercedes S-Class made of renewable raw materials (photo: Daimler Chrysler) The use of materials from renewable resources is really nothing new in the automotive industry. Natural fibres have been used for many years for their low density, their excellent mechanical and thermal properties, and of course their relatively low prices. Natural fibres that are used for automotive applications are flax, hemp, jute/kenaf, sisal etc. as well as wood and cotton. In a recent market study on natural fibres in the automotive industry the German „nova-Institut für Ökologie und Innovation“ published some figures on market volumes in Germany. nova-Institut found out that by the year 2005 approximately 30,000 tonnes of natural fibres were used in automotive applications in that country. The chart on the left shows the distribution of 19,000 tonnes of natural fibres, not including wood and cotton (for these two the institute could not obtain sufficient figures within their survey). However, nova-Institut estimates the quantity for 2005 at about 27,000 tonnes of wood fibre and about 40,000 tonnes of respective wood fibre composites. For cotton, previous studies (2004) had stated about 45,000 tonnes of cotton and about 79,000 tonnes of respective composites for the year 2003. “And the amount of natural fibres in cars has been continuously increasing over recent years”, says Michael Carus from the nova-Institut, “The matrix is still PP in most cases, but it might well be PLA in a few years,” he adds. 14 bioplastics MAGAZINE [01/07] Vol. 2
Automotive Applications of natural fibre composites include inner door linings (1.2 - 1.8 kg of natural fibres front and 0.8 - 1.5 kg in rear doors), trunk liners (up to 2 kg of natural fibres), rear shelves, roofliners, instrument panels, all kind of covers as well as injection moulded applications such as ventilation grilles. Pioneers in “automotive bioplastics” It was as early as in the first decade of the 20th century when Henry Ford started experimenting with the use of agricultural products for automotive applications. In 1915 a first production application was a coil housing for the Model-T Ford, made from a wheat gluten resin reinforced with asbestos fibres. Later Ford intensified his research on the use of a so-called soy meal. As fillers at up to 50 to 60 percent, cellulose fibres from hemp, wood flour or pulp from pine, cotton, flax, ramie, and even wheat, were used in combination with the soy meal. Soy meal plastics were used for a steadily increasing number of automobile parts, such as glove-box doors, gear-shift knobs, horn buttons, accelerator pedals, distributor heads, interior trim, steering wheels, instrument panels, and eventually a prototype exterior rear-deck lid (www. hempplastic.com). Polyurethane Even today, Ford Motor Company is investigating the use of soy for natural-based automotive applications. Ford researchers have formulated the chemistry to replace a staggering 40% of the standard petroleum-based polyol (one of the basic components of polyurethane) with a soy-derived material. While many in the auto industry are experimenting with a 5% soy-based polyol, “at 40%, we have the ability to make a significant impact on the environment, while reducing our dependency on imported petroleum”, says Dr. Matthew Zaluzec, manager of Ford‘s Materials Research & Advanced Engineering Department. PLA and kenaf Another pioneer of modern bioplastics for automotive applications is Toyota Motor Corporation. The Toyota RAUM, a domestic model introduced in 2003 is equipped with a cover for the spare tyre made of Toyota Eco-Plastic. This PLA material is based on sugar beet and, for the spare wheel cover, combined with kenaf fibres. At their own PLA pilot plant, the “Hirose Plant” with an annual output of 1,000 tonnes, Toyota have researched and tried various raw materials including sweet potatoes grown in Indonesia. The output of the plant is mainly for Toyota‘s internal use and external non-automotive applications such as on-desk cell-phone chargers, tennis racket strings or inner cases for cosmetics products, all of these being sold only in Japan. Toyota also produced floor mats making use of PLA in order to demonstrate this application to customers. This project has since been terminated, according to Hiroshi Higuchi, General Manager of Toyota‘s Bio-Plastic Project Department, Biotechnology & Afforestation Division. Henry Ford tests his car made from plant-based materials- including hemp „The axe bounced, and there was no dent...“ photo from „A Modern Introduction To Hemp“ by Paul Benhaim available www.hemp.co.uk photos: Toyota bioplastics MAGAZINE [01/07] Vol. 2 15
