High-volume Packaging Production Requires Flexible SPC

Any plant visitor to Portage Plastics Corp. (PPC) would be amazed at the variety of containers rolling off the production lines on a typical workday - from instant cereal bowls to clamshell packaging for windshield wiper blades to containers for baby wipes - more sizes and shapes of trays and lids than one could ever imagine.

PPC thermoforms packaging for a broad range of industries including food, automotive, electronics, personal care, agriculture, hardware and medical industries. For their larger customers, the production volume totals millions of units a year. Flange width, part depth and thickness are the most critical dimensions affecting part quality at PPC.

Their Synergy 2000™ SPC software implementation in 2006 brought an end to a disappointing eight-year relationship with their previous SPC software vendor. To turn the situation around, PPC embarked on an intensive nine-month evaluation of potential SPC systems including a pilot project to compare the available technologies. Their primary objective was flexibility.

Industry-independent analytics

"Because every customer's job is unique, I needed a program that would let me analyze the data in numerous ways regardless of the differences in our customers' processes," says Heidi Beaver, PPC's Certified Quality Technician.

Synergy 2000 has enhanced the company's ability to pinpoint and react to adverse events that occur during production such as oven or heating issues, ambient temperature changes, material issues, trim press vibration, equipment maintenance issues or over-adjustments to machines. The software is used within the Quality Assurance Lab at PPC headquarters in Portage, WI, and is networked to a satellite manufacturing facility in Brownsville, TX. Measurements are automatically entered into the software using calipers and digital indicators which eliminates keyboard data entry and improves accuracy.

New ways of looking at the process

"The versatility in the query function gives me the exact data I need at any given time. With our old SPC software, I could only look at a 48-cavity tool as the entire process: six rows across and eight deep," she explains. "Now I look at the process by individual rows because we can get performance difference with the outside rows than we do from the inside rows. Therefore, I can determine immediately that my biggest shrink factor is affecting the outside rows, or know we have heating issues if we get thin sidewalls."

A comprehensive selection of SPC charts allows PPC to see drifts in the process that might be missed by merely viewing spreadsheet data. According to Beaver, the overlay chart is one of her most useful analytical tools: "If we see trends we don't like, I can take data from several production runs and overlay them onto one control chart to make comparisons."

Integrated quality and production

Their Texas location is staffed with a Quality Technician for the day shift only, so real-time, networked SPC has been moved to the actual point of production. Operators have been trained to take their own part measurements and enter the data directly into Synergy 2000 during second and third shifts. At the same time, their Wisconsin headquarters is able to view the data and receive notification of what is occurring remotely.

"Our Engineers are absolutely sold on the system. Understanding how our processes work is definitely leading to better problem-solving and higher parts-per-million quality," says Beaver.

Quality Manager Paul Bauer agrees: "The biggest advantage from our SPC program is the ability to assess process capability. It provides us with the data to make process improvements one product at a time." As an example, PPC saved $21,000 by monitoring just one key quality characteristic on a high-volume product over the course of a year. That practice can make a substantial annual financial contribution considering the company's total production output across its large and diversified customer base.