Abstract:
From the case literature reviewed, it was found that 54.66% of all defects from plastic sheet process were non-melted PVC particle on product surface. The value of this is about 1,561,716 baht per year. As the result, product was stored for recycling that incurs the higher cost for production. Thus, the objective of this research is to decrease the amount of defectives from non-melted PVC particle on product by using design and analysis of experiment. This is to study the influence of parameters that affect to non-melting of the PVC particles on product surface and to find the optimal conditions by using response surface technique. The result from statistical analysis indicated that 180°C melting temperature of PVC compound and 30 Kg./Batch of re-melted of PVC sheet scrap at the Mixing Roll are the appropriate set point which can generate defect less than 10 point/m2. Moreover, the number of non-passed limitation of non-melted PVC particle on product surface verification can be reduced up to 80%.