Investigation on the pultrusion of thermoplastic preimpregnated polypropylene-glass tapes

Abstract

Pultrusion processes have been widely used and developed to produce composite profiles in fiber-reinforced thermoset. Recently industry and research community are investigating the adoption of thermoplastic polymers in the production of pultruded components exhibiting structural stability at higher temperatures and improved sustainability. Aiming to study the thermoplastic pultrusion process and how the process parameters settings affect the composite profiles produced, a laboratory-scale pultrusion line has been designed and produced. The pultrusion die is fed by polypropylene pre-impregnated tapes reinforced by unidirectional continuous glass fibers. It consists of a tapered converging cavity heated by electrical plates governed by PID controllers and a straight cooling die. This work aims to study the feasibility of the process, the consolidation of the tapes, and the interactions between the processed materials and the cavity walls by using embedded traveling thermocouples and load cells. The experimental test presented in this paper highlights that the preimpregnated tapes processed have been well-consolidated with the parameters adopted and the pultruded profile presents good quality at a visual inspection of the external surfaces and cross-section, indicating a good melting and hardening of the polypropylene matrix. The interactions between the processed materials and the die walls are evaluated by means of a cross-analysis of thermal and load data.