University of Houston studies exploring the potential of silk fiber composites

Youssef Hamidi, an assistant professor of mechanical engineering at the University of Houston-Cleanhu University, presented samples of his silk- fiber composites . He said silk fibers would make composites more resilient to impact and stress. This increases the likelihood of manufacturing load-bearing composites that can replace most of the steel used in automobiles and other finished products.

Youssef Hamidi, assistant professor of mechanical engineering at the University of Houston, Texas (UHCL), is studying silk fibers for composite materials to meet natural fiber reinforcement for strength, light weight and sustainability. The growing demand for composite materials.

In his recent study published in the journal Materials, Hamidi claims that silk fibers are more tough than traditional fiberglass or carbon fibers and have high tensile strength, making them less brittle and more resistant to impact. And stress. He said that this has increased the possibility of manufacturing load-bearing silk fiber reinforced composites for the automotive and other industries. Hamidi joined the UHCL School of Mechanical Engineering in 2018 and has been researching composite materials since 2000, focusing on how to reduce process-induced defects.

He and his colleagues at the School of Aerospace and Mechanical Engineering at the University of Oklahoma (Norman, Oklahoma, USA) began using silk a year ago.

"I think what is the most appropriate," Hamidi said. In most (biobased) applications, short plant-based fibers are used. But silk has higher performance. It is easy to buy. It is not lacking. ".

For the first time, Hamidi used silk that was extracted directly from silkworm cocoons, but found it troublesome. He soon found that the silk on the shelves worked best. However, he found that once the resin was dried, it left tiny voids or bubbles inside the resin, and the resin could not completely adhere to the fabric. Understanding how these voids are formed and how to eliminate them is the subject of Dr. Hamidi's thesis.

According to Hamidi, these are common problems in the manufacture of composites and are usually solved by using autoclaves to eliminate defects in the molding process. However, since the idea behind Hamidi research is to create a low-cost alternative to high-cost manufacturing processes, he is working to find a solution that does not rely on expensive autoclave therapy.

In his current research, Hamidi is addressing resin/fiber adhesion problems. To this end, he turned to scale adjustment.

Hamidi hopes that the use of a suitable sizing agent on silk fabrics will improve the adhesion of the resin and reduce voids, resulting in a significant improvement in the performance of the silk fiber composite.

He is currently working with a professor of chemistry at the University of California at Berkeley to come up with a better sizing agent. He said: "We need to find the right size to improve adhesion."

“Normally, the mechanical properties of a composite are determined by this combination. We can change most of the mechanical properties of a composite by changing the chemical composition and sizing of the sizing.”