Abstract:
Plastic was frequently used in our daily life as a consumable product, it also causes large amount of plastic waste in the environment. This research is focusing on recycling virgin HDPE plastic pellets mixed with HDPE plastic from used chlorine tank. The ratio of blended 100 : 050 : 50 40 : 60 30 : 70 20 : 80 and 0 : 100 wt%, respectively. Thermal properties were tested using differential scanning calorimetry. It was found that thermal properties were not different and the melting temperature did not change. Therefore, 100% PCR plastic pellets was chosen for recycling with twin screw extruder at 0 5 10 20 50 and 80 recycle time, respectively. The thermal degradation result testing by simultaneous thermal analyzer showed slightly change during 0-5 recycle time and unchanged after that until 80 recycle time. The viscosity in term of melt flow index value increased during 0-10 recycle time and gradually decreased after 20th recycle time. The rheological property of recycle PCR exhibited shear thinning behavior and short linear viscoelastic after recycling. Moreover, the frequency measurement showed higher elastic solids character than viscous liquid character owing to the degradation of polymer molecules to carbon particle. Mechanical properties slightly changed after recycling more than 20th recycle time while the color of the plastic significantly changed after the 20th recycle time. Finally, using single screw extruder for processing did not change the property of PCR but using twin screw extruder for processing showed slightly change in thermal, physical, and mechanical properties due to heat accumulation and high shear force during processing