A Comprehensive Solution with Low Preform Quality and Difficult Production Management

Category: Industry Information

Release time:2020-07-08

In the preform production process, especially the production of large preforms, there is a very headache - product quality control. How to prevent problematic preforms from flowing into the next process, how to isolate potentially problematic preforms in millions or even tens of millions of preforms, perhaps the previous solution was manual inspection. Now with SPC it can be easily solved.

The production of the above bad preforms is often a change in the production process, such as changes in process parameters such as temperature, speed and pressure, back pressure, time, etc. Controlling the stability of process parameters is the key to the quality of He Zheng preforms, and the basis for ensuring the stability of process parameters lies in the early warning and traceability of problems, which requires SPC to achieve.

　　SPC

Statistical Process Control, abbreviated as "SPC", is a process control tool with the help of mathematical statistical methods. It analyzes and evaluates the production process, finds the signs of systemic factors in time according to the feedback information, and takes measures to eliminate their influence, so that the process is maintained in a controlled state only affected by random factors, so as to achieve the purpose of quality control.

In the field of embryo injection, SPC can self-learn and detect the product process, and monitor it in real time according to the statistical model, helping users find problems in time and adjust the process to ensure the consistency of the product. In the exchange with some large domestic PET preform manufacturers, we found that their requirements for SPC are extremely strict, mainly because their customers have high requirements for the quality of preforms (such as Coca-Cola, Danone, Nestle, etc.), once the quality is not up to standard, it will cause return disputes. The full-featured SPC software package can help preform suppliers detect changes in production process parameters and curves in time, correct and alarm, and control shutdown in severe cases to avoid more scrap; Customers can comprehensively analyze the time and alarm event curves to determine the problem, increase the preform detection of the batch, and ensure the conformity of the product.

How SPC works

Samples are collected according to the system, and time and statistical calculation results are plotted. In process control, parameters fluctuate around the control mean. The horizontal centerline in the figure represents the controllable state, and the centerline serves as a reference line for drawing tracing points. When the process fluctuates, the average value changes, which is considered a state of loss of control. If the process is out of control at one or more plotted points in time, the corresponding fluctuations may be greater.

SPC in the FORAY embryo injection system. It makes products and services stably meet customer requirements through evaluation conclusions such as normal distribution, statistical control status, process capability, etc. Through the SPC mathematical model (process discrimination rule), the product quality problems that may occur in the future can be predicted to avoid production risks for customers.

According to the international SPC statistical method, we focus on providing analysis tools such as trend and distribution histogram, XBar plot, R/S plot and Cpk (process capability index).

SPC in the FORAY embryo injection system

1. Data report analysis

functionData report analysis function

Real-time comparison and monitoring of historical data of process parameters, as well as tabular extraction of data from the last one or two months stored in the historical database for analysis and comparison. The table can show a comparison of individual SPC process parameters for up to 2000 cycles (configurable) or directly from the historical database from previous periods (if hard disk space is available, historical data from a year or two ago) for analysis. At the top of the table, the SPC process parameters (upper and lower limits, Cpk (Control Process Capability) and other information for the current cycle are always displayed.

2. Overview of process data

It can list the upper and lower limits of all SPC process parameters, Cpk, and various alarm control information.

3. Historical data trend chart analysis

SPC is closely related to the historical data of alarm events, and users can click any time point to display the changes of the corresponding SPC process parameters and the modification of related alarms and control parameters, so as to understand the reasons for changes in process parameters in time. Functions such as zooming in/zooming out/searching forward/searching backward on historical data are also available for customer analysis.