Precise temperature measurement is critical in thermoforming plastic products and parts, and is the key that helped two Colorado companies master the ability to create parts for unique products. Associated Thermoforming, Inc. (ATI) of Berthold, CO specializes in technically challenging plastics solutions and has pioneered some unique twin-sheet thermoforming applications and techniques over the 27 years they’ve been in business. They’ve tooled and manufactured structural and decorative parts for many industries, including medical, automotive, recreation, food /beverage, and computer and data storage, and they know how to use heat to get the results their customers require.
But when representatives of SKYDEX, Inc. in nearby Centennial, CO came calling with new product part requirements, some serious head scratching went on, according to ATI President John Nix. SKYDEX had patented a cushioning and protective material that is used in footwear, helmets, seating, protective gear, playground surfacing and many other applications. Its materials are used by some of the most famous brands in a wide variety of high performance athletic products as well as the United States military and other militaries for applications ranging from paratrooper helmet components to Navy SEAL boat decking.
While ATI works primarily with material gauges of .060" up to .400" in a wide variety of resins, and can perform high definition pressure-forming to exacting tolerances, SKYDEX parts were different.
“Most products are heavy gauge and pretty forgiving, but with the SKYDEX products, a one or two-degree temperature difference wouldn’t get it done,” Nix said.
In the thermoforming process, parts are produced from a flat sheet of plastic that is placed under precise temperatures and atmospheric pressure. After struggling to meet the SKYDEX parts requirements, Nix decided he needed a better way to monitor his production process. He called Raytek, a worldwide leader in noncontact thermometry, looking for a solution.
“How we heat the sheet is critical,” he explained. “We didn’t know what the sheet was doing, we only knew what the oven was doing.”
ATI engineers had tried various ways to measure temperatures including putting probes on the sheet, and placing dots on it that would turn colors when they reached certain temperatures.
“They were crude ways to measure,” he added.
Then Raytek introduced the TF100 infrared temperature line scanner system. At the heart of the system is the MP50 process imager, which is mounted above or below the thermoforming sheet, wherever it has a clear viewing path. It measures a line of 256 points using a rotating mirror that scans a 90º field-of-view up to 48 times per second. The scanning can be initiated by the measured temperature, or by an external “trigger” signal. During the installation, Raytek engineers worked directly with ATI engineers to make the TF100 system software as user-friendly as their process needed.
“We really gained a tremendous benefit from using the infrared temperature line scanner,” Nix said. “We use zoned heating in huge ovens with a grid--like a spreadsheet. With the TF100 system, we can program each zone individually.”
In addition, the TF100 system provides accurate temperatures in real time and it has provided other benefits such as scrap reduction. Nix also uses it to look at his ovens.
“It’s become part of our preventive maintenance program,” he said.
ATI has six thermoforming machines and crews currently move the MP50 infrared temperature line scanner among them as needed. In the future, the company plans to add another machine and another TF100 system as well as other Raytek temperature measurement products including portable thermal imagers and hand-held model noncontact, infrared thermometers.
Nix said he doesn’t know the exact return on investment ATI has achieved as a result of the installation of the TF100 system beyond reduced scrap and the boost to his preventive maintenance program, except for the fact that he’s proud to be able to meet his customer’s needs.
“No one could have made these (SKYDEX) products without the line scanner,” he said. “It’s a key part of our process control.”
Noted by Kate McGuire, Raytek Corporation.