The crisp autumn weather and the changing of the leaves in New England draws visitors from all over the world. From Massachusetts to Maine, people can feast their eyes on famous foliage with blazing reds, golden yellows, and burnished oranges that stretch into the White Mountains up to the Canadian border. But there are other reasons to visit the Northeast at this time of year, especially if you’re in the thermoforming industry. Here in our corner of the US, we have our own little ecosystem of thermoforming companies: machinery makers, toolmakers, die makers, and, of course, the most important element of all, the plug assist specialists!
Brueckner Group’s Kiefel Division typically hosts their “Packaging Technology Days” in Portsmouth, NH around September / October. This year, Kiefel invited CMT and Sharples to participate in a more hands-on seminar that included a visit to a local thermoformer and a special dinner at Gillette Stadium, home of the New England Patriots and the New England Revolution. 50 people from all over the US and Canada attended, and they were treated to a series of demonstrations on the new Kiefel KMD90 Premier in-line thermoformer. But instead of simply running the machine and putting it through its paces, Kiefel and CMT set up a series of trials to compare the impact of 3rd motion plug assist against a fixed plug. Specifically, we measured the material distribution and top-load strength of parts made via the two different processes.
Generally speaking, 3rd motion plug assist is now a standard feature on most equipment around the world. Deep-draw parts, complex trays, and high-volume parts like K-cups are all typically run on systems where a servo-driven axis controls the speed and position of the plug. Having this level of control over your process affords you greater ability to manage the material distribution. Our tests set out to measure how much of an advantage this might offer to converters.
The part in question was an 8oz round tub, made from 0.037″ (0.93mm) APET. The 30-cavity tool with HYTAC WFT plugs was set up to run first as a fixed-plug and then as a 3rd motion plug. Parameters were established for both trials, with the same part (cavity #15) used for material distribution and top-load strength comparisons. The parts were measured in 14 spots at the 0 and 90 degree positions. Using a Magna Mike 8600 from Olympus, the data was loaded into an Excel spreadsheet where it was displayed for the attendees.
The part formed with the fixed plug showed an average minimum thickness of 0.012″ (0.3mm) and a top-load strength (33lbf). The part formed with the 3rd motion plug showed a higher average minimum thickness of 0.014″ (0.35mm) and a higher top load strength (47lbf). The measurements showed a 16% and a 42% increase, respectively. Importantly, the 3rd motion part also showed a lower standard deviation of material distribution, meaning that the part was more uniformly formed. This has important economic implications for converters because better distribution allows for downgauging without compromising quality. As CMT continues to demonstrate with partners around the world as part of our “Thermoforming 2.0″ approach to applied research, the value of even 1 mil (0.001” or 100 micron) can have a significant impact on your bottom line.
Why not get in touch and let us know how we can work together to help you optimize your forming process?