Studying the effect of irregular crumbling from recycled polymeric materials on selected characteristics of the extrusion process

Abstract

This work deals with the study of the effect of the irregular crumbling (Instability of cutting) for recycled polyethylene terephthalate (PET) bottles on the extrusion process using a twin-screw extruder and as a result its effect on the mechanical properties of the product and the amount of electrical energy consumption. The extrusion process was performed for cutting sizes of PET bottles (4.75, 6.75, 7.15, and 10 mm) in addition to raw material to compare, at temperature ranges between (200–205 °C) at speed of 50 rpm. Results showed that the cutting size has a direct effect on the crystallinity which affects mechanical and thermal properties, such as elongation and tensile strength decreases with increase cutting size but the elastic modulus increase with increase cutting size. The impact and hardness test proved that the impact strength and hardness decrease with increase cutting size, also, it was observed during the extrusion process when placing an equal amount of different sizes in the machine and ensure that the materials enter the machine at once for the sake of comparison, we find that the lower volumes consumed less electrical energy, compared to the rest of the other different sizes, except the raw material from (PET).