Mechanical Behavior of Highly-Flexible Elastomeric Composites with Knitted-Fabrie Reinforcement

This paper examines critical issues associated with the fabrication and forming of highly-flexible polymeric composites, reinforced with knitted-fabric structures. Knitted-fabric reinforcements have not generally been preferred over more traditional woven reinforcements in high-performance composites, mainly because of their lower stiffness/strength performance when embedded in a rigid, thermosetting matrix material. In this study, elastomeric materials such as polyurea and thermoplastic elastomer (TPE) were used to fabricate composites with knitted-fabric. Two different types of arrangements were experimentally studied: knitted fabric embedded in the elastomer and a sandwich of knitted fabric between elastomeric skins. It is shown that by fully utilizing the high stretchability of the knitted fabric reinforcements, attractive material properties can be obtained especially for energy/impact absorption and forming applications. The improvement of thermoforming process stability with the use of carefully tailored knitted fabric reinforcements is also presented.