Evonik Industries has developed and launched on the market a novel combination of bio-based high-performance polyamides and bio-based high-performance fibers.
Reinforcing fibers, particularly chopped fiberglass, are often mixed into a plastic to improve its mechanical properties. But in the case of bio-based polymers this means that the bio-content is lowered, reducing the ecological advantage. The use of natural fibers, on the other hand, has so far resulted in significant deterioration of reinforcing potential, and also an unpleasant odor in the end product. VESTAMID® Terra with rayon fibers retains the high bio-content—along with excellent reinforcing potential.
Two polyamide grades of the VESTAMID® Terra product family form the polymer matrix: Terra HS and Terra DS. These polyamides are fully or partially obtained from the castor oil plant. Commercially available chopped rayon fibers form the reinforcing fiber substrate. Rayon is also known as man-made cellulose or technically as viscose fibers. These fibers are obtained entirely from wood residues (dissolving pulp), and are therefore also based on renewable raw materials. The overall bio-content is thus high, lying between 67 and 100 percent.
Compared with fiberglass reinforced systems, the combination of viscose fibers and polymer matrix offers a significantly improved carbon balance. As an example, CO2 savings for a viscose fiber system of PA1010 with a fiber content of 30% are 57 percent higher than for a 30% glass fiber reinforced PA66.
Additionally, viscose reinforcing fibers have a significantly lower density than mineral fibers: Depending on fiber content, bio-polyamides reinforced with viscose fibers offer a weight reduction of up to 10%, for the same reinforcing performance.