Relationship between the processing parameters and tensile properties of air textured Kevlar yarns

Abstract

Air texturing is an extremely versatile mechanical yarn bulking process that improves the handle and tactile properties of continuous multifilament yarns. Kevlar, poly(p-phenylene terephthalamide) , due to its excellent mechanical and thermal properties has found wide ranging applications in protective clothing, however the filament has poor tactile properties. Air texturing could thus be the process of choice for improving handle by imparting bulk to the multifilament yarn however improvement of the surface characteristics is at the expense of tensile strength of the yarn.

The thesis reports an experimental study which was carried out to determine the influence of the key processing parameters on the resultant tensile strength, strain and moduli properties of the yarn. A further objective of the research work was to develop novel structures that will have good surface properties with minimal compromise in the axial strength.

In order to accomplish this goal, a literature review along with preliminary trials was conducted to document the texturing process and to select the key process variables. Based on these findings a three factorial experiment was conducted to achieve the objectives.

The results showed that processing conditions have an influence over the resultant tensile properties. The study also explores a novel yarn structure that has loops on the surface while the orientation of the core is retained.