Study of injection process capability in production of plastic boxes

Abstract

Ensuring the process capability currently means the warranty that produced products will be in accordance with requirements, both on the company's as well as customer's side. This study focuses on the statistical control of injection process capability in serial production in a company focusing on products for healthcare. The injection process is evaluated by control charts, specifically by control chart for average and range ( , R). As the results showed, based on the chart for average and range, we are able to say that the injection process is under statistical control. The requirement for process capability was met; the indices of process capability Cp and Cpk are higher than the determined value 1.33. The normality of measured values was verified by histogram. The obtained values are: Cp = 1.85 and Cpk = 1.82. Therefore, we may consider the process as capable.