Thermoforming Statistical Process Control Integral Part of QA
In keeping with our focus on thermoforming statistical process control, we use SPC, or Statistical Process Control, to monitor process variables. SPC is part of the ‘Six Sigma” philosophy, used to see how consistently our processes are controlled. Over time, manufacturing processes tend to deviate from the standard. Thus, we use the Sigma unit to measure the amount of deviation from the required specification. We use a CP Cpk worksheet (shown above) to enter data collected throughout production jobs in an attempt to evaluate our process. CP is the capability index which measures how well our data fits between the upper and lower specifications. In addition, we use histograms (image 2) to visually see the distribution of our data. The histogram illustrates this distribution of data. To summarize, the histogram is very helpful in allowing us to see how good our process is.