Novel polymeric monofilament post-treatment study involving time-of-flight measurements

The goal of polymeric fiber post-treatment is to achieve--under reproducible, nontransient conditions--significant enhancement of the mechanical properties of drawn fiber over those of undrawn fiber. Mechanical property enhancement is closely tied to macroscale orientation imparted to the monofilament through a combination of heat and draw over a short period of time. Drawing is difficult to characterize because the effective draw ratio, (lambda) , varies as a function of time before it may reach a steady-state value. As a result, the monofilament line may break or develop nonuniform mechanical properties before the limiting regime is reached. A pilot device has been designed and built to characterize and control the vital parameters associated with monofilament post-treatment in order to study the conditions which lead to production of superior fiber product. This monofilament post-treatment device incorporates real-time computer feedback, microcontroller processing, and laser interruption time-of-flight techniques to study the conditions leading to steady-state, maximal draw of polyester blend fibers. The applications of this device are broad: it may be used to study the transient drawing behavior of an extensive variety of monofilaments.