Tensile Properties of Extruded Short Glass Fibre/Low Density Polyethylene Composites.

Home-made single screw extruder was designed and constructed with screw length to diameter ratio 20:1 operating at different screw speeds ranging from 7-28 rpm and at different temperatures. The extruder was used to produce rod composite samples composed of low density polyethylene and short E-glass fibre. The effects of fibre contents and extruder operating variables on the tensile modulus and ductility were investigated. The tensile modulus increased with fibre weight percent up to 10.52 wt% as residual fibre content (20 wt% prepared sample before processing) and had a value of 827 MPa, then slightly decreased to lower values due to bad wettability and poor distribution/dispersion of fibres in the LOPE matrix. The clear decrease in fibre content after processing (residual fibre content) which is about 4055% is due to the sticking of fibres in hopper or in the different extruder zones. On the other hand, ductility as percentage elongation-at-break decreased significantly at low fibre concentration then decreased in lower rate at higher fibre contents. Operating variables of the extruder were found to affect the tensile properties of LOPE/glass fibre composites by affecting the interfacial adhesion between the two components. This effect was clear from the analyzed data of the modulus efficiency factor KE.