Zelfo - An engineering material fully based on renewable resources

The development of zelfo was based on a review on technologies for the prod uction of "papier mache" in the second half of the 19th century. However, i n contrast to "papier mache" Zelfo does not contain any additional bonding agent. Potential raw materials for the production of Zelfo include various plants and wastes with a high cellulose content (e.g., hemp, flax, waste pa per). The first production step is a refining process, in which the raw mat erials are simultaneously hackled and ground and mixed with water. The resu lt of this process is a microfiberpulp with a solid content of 1 to 15 m%. which is subsequently predried, cast or molded into a final shape and dried . Due to the possible variations in raw materials and in the production pro cess, properties of Zelfo can be varied over a certain range. For example, values for density from 0.5 to 1.5 g/cm(-3), for tensile modulus from 1500 to 6550 MPa and for tensile strength from 7 to 55 MPa can be achieved, Thus , Zelfo is likely to compete with both conventional plastics and chipboard for certain applications.