Study of process stability in injection molding based on product weight

This paper describes a stability study of a plastic injection molding process. There is a need - underpinned by economic considerations - to continuously improve and lead to a maximum reduction in the level of deficiencies in production processes. One of the methods that can help to improve the process is SPC (Statistical Process Control). One of the SPC tools are proces capability indicators (Cp, Cpk) or performance indicators, such as Pp, Ppk. In this paper, on a mass measuring station, a study was conducted on three types of products manufactured in a company, and the measurements concerned each piece of the product manufactured during one work shift. The data collected were used to calculate the process capability and to evaluate these processes.