Various automobile parts are made from plastics, which are reliant on the supply of petroleum. There is a need to find new materials for these parts so we can promote a post-petroleum era and reduce CO2 emissions.
All of Mazda's biomaterials fall under the Mazda Biotechmaterial brand name. Leveraging the latest biotechnologies, Mazda is dedicated to continuing its research and development of plant-derived materials for automobile parts.
In 2006, joint research by industry, academia and the Japanese government has successfully produced the automobile industry's first plant-derived bioplastic, which can be injection-molded to ensure thermal and shock resistance and a beautiful finish. Currently, we are aiming to develop a new bioplastic from non-food-based cellulosic biomass. In collaboration with local companies, we have also developed the world's first 100 percent plant-derived biofabric, which is well suited for automobile seat covers.
To be suitable for use as automobile parts, plant-derived plastics (bioplastics) must have the required strength (shock impact resistance) and heat resistance. Mazda participated in a joint research project between industry, academia and local government*1 in Hiroshima prefecture. It resulted in the creation of a bioplastic with the high strength, heat resistance and high quality finish necessary for injection-molded automobile interior parts. It is the first bioplastic in the automobile industry that maintains a high plant-derived content (over 80 percent). We altered the molecular structure of polylactic acid extracted from plants to raise its melting point and developed it as a nucleating agent. A compatibilizer compound*2 was also developed to highly disperse the shock-absorbing flexible ingredients. These two breakthroughs improved material's ability to uniformly absorb and release energy generated by impacts. This bioplastic is three times the shock impact resistance along with 25 percent higher heat resistance when compared to contemporary bioplastics used for items such as electrical appliances.
And unlike conventional bioplastics whose properties are suitable for press-forming only, Mazda's bioplastic can be extrusion-molded. Consequently, this bioplastic can be used for various car parts. The Premacy Hydrogen RE Hybrid featured this bioplastic in the vehicle's instrument panel and other interior fittings.
- *1 Hiroshima University, Nishikawa rubber Co. Ltd., Western Hiroshima Prefecture Industrial Research Institute, G. P. Daikyo corporation, Japan Steel Works Ltd., Kinki University School of Engineering, Nishikawa Kasei Co. Ltd., National Research Institute of Brewing, Yasuhara Chemical Co., Ltd., MANAC Incorporated and Mazda Motor Corporation.
- *2 An additive that is used to ensure uniform distribution of two or more different types of properties in order to improve the physical properties of the material. The additive is necessary to mix the polyactic acids with a combination of polylactic acid and an added element that is not chemically compatible.
Mazda's bioplastic is a plant-derived and carbon-neutral*3 material. It reduces reliance on fossil fuels and therefore also cuts CO2 emissions. In addition, its manufacture involves fermentation of natural materials such as starches and sugars. As a result, it requires 30 percent less energy to plastics, which means parts can be thinner so less material is required for production.
- *3 The same amount of CO2 that is released when the bioplastic decomposes or is burnt is absorbed by growing plants through photosynthesis. Therefore, Mazda's bioplastic has a negligible impact on total atmospheric CO2 levels.
Mazda developed biofabric made with completely plant-drived fibers that has quality and durability suitable for use in vehicle interior in collaboration with Teijin Limited and Teijin Fibers Limited, both are based in the Chugoku/Shikoku area, Mazda's home region.
This biofabric possesses the qualities and durability required for use in vehicle seat covers. Resistant to abrasion and damage from sunlight, in addition to being flame retardant, the new biofabric meets the highest quality standards. Based on this biotechnology, Mazda will strengthen its future research and development on non-food-based materials in consideration of the impact such technologies have on food supplies.
Suitability for seat covers
Mazda's biofabric uses a new polylactic acid*4 which was created during development of Mazda's bioplastic as a crystallization agent to control the entire molecular architecture of raw resins to form a “stereocomplex structure.*5 ” The technique was used to improve fiber strength until the fabric attained sufficient resistance to abrasion and light damage for practical use in vehicle seat covers.
The technology enables the production of fibers made from 100 percent plant-derived polylactic acid which are well-suited for automobile applications. Other crucial qualities necessary for the highest performing fabrics, such as fire retardant properties, were achieved through Mazda's accumulated experience in surface processing technologies built up through years of cooperation with several partner companies.
- *4 A plastic created by combining large numbers of lactic acid molecules that are made from fermented carbohydrates such as plant sugars.
- *5 A strong crystalline structure made by blending the L and D enantiomers of polylactic acid.