Clean Tech

Success with The Center

CLEAN TECH: Achieving Time & Cost Savings With Six Sigma

The knowledge I took away from The Center’s Six Sigma Black Belt course allowed our company to re-examine our processes to maximize efficiency and problem-solve our measurement system concerns.
-- Steve Slack, Quality Manager

In 1989, Clean Tech, Inc. ( was founded with the mission of reclaiming plastic from water containers and other post-consumer packaging. Now three decades later, the company recycles more than three billion bottles per year and continues to invest in recycling technology and operational improvements. Headquartered in Dundee, Mich., with 153 employees and a presence in Europe, Clean Tech is guided by the core values of accountability, integrity, innovation, environment, community and more. With these values still driving the business today, Clean Tech continues to meet high conservation standards while enhancing the health and safety for their employees and communities.


While reviewing plant metrics, sales orders and forecasts, Clean Tech’s quality team discovered extrusion lines were not reaching full capacity. Utilizing tools such as a Pareto Chart, the team identified the largest contributors for the reduced throughput and shutdowns. It was uncovered that the current measurement system needed to remove these shutdowns was not providing reliable data. Not only did the test take more time than was available, historical data between the lab and the line was not matching up, causing distrust in their system.


Image for Clean Tech

To gain the analytical skills and insight needed to evaluate and improve this process, Clean Tech’s Quality Manager attended Six Sigma Black Belt training at the Michigan Manufacturing Technology Center (The Center). As part of this training, he led his team through several rounds of improvements. Goals of the project include:

• Correct problems with the measurement system, which would enable Clean Tech to work on efficiency, reduce cycle time and produce timely data.
• Increase testing capacity to accommodate a new line, which was starting soon, that was expected to double capacity in the plant.
• Set and achieve an improved %Tolerance target.

To begin, the team used a SIPOC (suppliers, inputs, process, outputs, customers) diagram and a detailed process map to gain a better understanding of the process inputs and outputs. Focused brainstorming tools, such as a fishbone diagram and team voting, were used to list potential factors and prioritize what theories to investigate first. Various studies were conducted to determine which factors were important. With that data, the team proved the current measurement system could not be improved enough to meet the goals and a new piece of equipment was required.

The final phase of the project included installing and validating the new measurement instrument. It was found, by the initial out-of-the-box Gage R&R, that some tuning would be required. The team learned the sample could degrade if heated too long by the instrument. A water line was installed that would initiate a cooling ramp to keep the temperature lower. With the new test method and instrument in place, the team ran a new validation test to verify it was ready for production.
The project wrapped up with work instructions, calibration program updates, the creation of control samples, a formal reaction plan and key takeaways to ensure the gains achieved would be sustained over time.


  • Cycle time reduced from 236.6 mins to 51.63 mins. (184.97 min savings)
  • Increased Capacity: 90%
  • Achieved Gage R&R %Tolerance target of 92.4%
  • Created work instructions for new processes, updated calibration programs and established reaction plans for future failures.