Now viewing: quality measurement

Ken Roney
By Ken Roney
Friday, August 9, 2013 - 15:30

As customer demands grow ever more complex and tolerances tighten, it is incumbent on us, as injection molders, to continually innovate and improve our processes to meet these growing demands. The tools of statistical process control are very helpful in understanding our process capabilities, identifying unwanted variation, and “fine-tuning” our processes. Overall, it enables us to efficiently and consistently meet our customer’s increasing demands for quality, cost and delivery.

Statistical techniques have been around for decades, having been most primarily developed by Walter Shewhart at the Bell Labs in the 1920’s. Since then many companies worldwide have implemented a wide variety of statistical tools to help reduce costs by working more efficiently; by reducing variation in their production processes. This in turn results in reduced scrap or re-works. These tools include things as simple as graphing to more complex tools/analysis including Pareto Analysis, Histograms, Capability Analysis, Fishbone Charts and Control Charts. Statistical software is available to make the “data crunching” quick, easy, and easily interpreted and used.

At Elite Plastics we use our statistical software package to provide us a quick view of how our injection molding processes are preforming by analyzing data from internal key product characteristics and/or customer driven product features. This data can be viewed as a line graph (individual charting), or by stratifying the data into a histogram (including process capability indexes – Cp, Cpk) or control chart (typically x-bar/R). These tools allow us to quickly identify our process condition and give solid data back to our process engineers in the event they need to investigate a production process issue.

The Value of SPC for Elite Plastics

It’s critical, when dealing with a large array of customer parts, to understand our machines capabilities and production processes. We work with a wide variety of part sizes, shapes, and complexities every day. Being able to make quick decisions based on statistical data, developed both during initial qualification as well as during in-process production, gives us flexibility in production and allows us to develop sound process controls. In turn, reducing scrap and re-work costs while maximizing our production activity.  In an upcoming blog I’ll discuss two of our most commonly used tools – Capability Indexes (Cpk) and Control Charts.

Bruce Wold
By Bruce Wold
Friday, November 11, 2011 - 13:03

As Elite Plastics continues to grow, one area in which we have had a constant focus is quality.  Recently we have added to our family of measurement equipment with this vision and touch probe capable CMM from Hexagon Metrology.  Qualification and validation of any process is key to any program's success.
Knowing that, it is very important that your equipment and fixturing is highly repeatable.  Here at Elite Plastics, repeatability is controlled and measured by performing Gauge studies.  This new piece of equipment adds to an already impressive arsenal of equipment and ensures we can continue to provide the best overall quality!