Low-cost natural fibers can help automotive companies looking to produce a more sustainable car. The headliner, usually a composite material that is adhered to the inside roof of a car, is a prime example of a low-cost part that could be made with sustainable materials.
Dr. Joseph Greene, professor of sustainable manufacturing and mechanical engineering at Chico State, conducted studies, funded by the Almond Board of California, to identify low-cost materials made from natural fibers and biodegradable plastics.
Using different recipes of almond shells and recycled polypropylene plastic, he compounded and molded plastic and natural fibers to produce several interior parts for testing. Biodegradable plastics were also made for comparison to recycled plastics. Dr. Greene and his team made 10 tensile bar and impact bar parts of various material combinations. They tested the plastic parts for tensile and impact strengths and quality appearance. They found that the addition of almond shells increased the plastic’s tensile and impact strengths.
Greene plans to work with Ford Motor Co. to produce interior parts for a new model truck, making parts with recycled polypropylene or biodegradable plastics that contain between 20 percent and 40 percent almond shells. He is developing a manufacturing and engineering process to produce sustainable plastics with almonds shells and recycled or biodegradable plastics.
Almonds, one of the largest food crops in California, leave large amounts of waste product in the form of its shells. Using the shells’ natural fibers reduces natural product waste and assists in the discovery of more sustainable solutions for cars at lower costs.
In addition, Greene is working on creating a plastic bag that has an attractive surface and a textured feel for use on the interior of a car. He made plastic bags with the natural fiber by blending almond shells, which contain about 50 percent cellulose, with recycled polyethylene. Plastic bags made with three percent almond shells had increased tear and impact strengths, he discovered that the bags’ texture felt similar to leather. Roplast Industries of Oroville, California, which produce reusable plastic bags and garment bags for Nike, is interested in producing the new cellulose polyethylene bag if an appropriate manufacturing process can be developed.