Statistical process control of the vertical form, fill and seal packaging machine in food industry

Abstract

AbstractIn food industry, high variability is quite common due to seasonality of raw materials and perishable products. Statistical Process Control (SPC) is an effective methodology to reduce variability and to make predictable processes. Literature still lacks of practical approaches of SPC implementation in food operations. Thus, this paper aims to propose a SPC method for quality control of a packaging process of fruit pulp sachets. This method is based on phase I and II study of P control chart for process stability and capability assessment. In phase I, special causes of variation were found and corrected in order to prevent against recurrence. After eliminating special causes of variation, the process capability has been reported as 2 sigma quality level. In phase II, an online monitoring procedure has been implemented and there was no special causes of variation in the packaging operation, assuring process stability.Practical applicationsThe proposed method provides to the production supervisor a very powerful and straightforward tool for quality control. Basically, if at any daily production the fraction of defectives goes below lower control limit or above upper control limit, immediately, the supervisor has to conduct the procedure for detecting special cause of variation. The proposed method was very successful for assuring process stability during online monitoring. The fraction of defectives items was remained in statistical control while the ongoing monitoring was being performed.