Thesis Details

Thesis Title: The ballistic resistance, tensile strength, flexural strength, and compressive strength of selected thermoplastic matrix composites
Thesis Author: Erick C. Miller
Abstract: Composites are materials composed of a fiber reinforcement and a matrix, or plastic, to bind the reinforcement together. The conventional manufacturing uses two steps. The first step is prepregging. The fiber reinforcement is soaked in a resin monomer. The resulting mixture is the pre impregnated reinforcement or prepreg. Layers of prepreg are stacked together. Heat and pressure are applied to cure the resin. Using a prepreg is costly. The prepreg must be refrigerated while stored. It has a limited shelf life. This thesis attempted to find a textile alternative to the prepregging process. Core spinning was used instead of prepregging. The staple sheath was a thermoplastic fiber: polyester polyamide and polyethylene were used. The core was Kevlar 29. Four performance measures were used to estimate the quality of the composites made: ballistic resistance, compressive strength, flexural strength and tensile strength. These properties were compared to the same properties for conventional composites. The compressive, flexural, and tensile strengths are lower than the strengths for conventional composites. The polyethylene matrix composites had excellent ballistic resistance. The polyamide matrix composites had the best compressive and flexural strengths of the composites made. Based on the information gathered for this thesis, this process is a viable way to make composites. Substantial improvements in properties are possible by changing fabric structure, more careful sheath fiber selection, adhesion promoters and by more thorough cleaning of the fabric.