Advanced Energy Works to Improve XPRES Mug Decoration Process

December 13, 2000

XPRES Corporation is a world-leading manufacturer of decorative coffee mugs. Using vibrant colors, their mugs feature city scenes, NFL logos, famous corporate logos, Bugs Bunny, dogs, and the famous Harry Potter. They recently experienced some quality problems with the decorative printing of their products. Conducting tests at both the XPRES facility in Winston-Salem and in its own Industrial Energy Lab, Advanced Energy has analyzed the existing production process and identified methods to help XPRES improve both quality and productivity.

While XPRES is already familiar with infrared (IR) technology , they currently use more traditional heating methods for the sublimation decorating--or transfer printing--of coffee mugs. Before suggesting any major changes to solve their problem, Advanced Energy's engineering staff first took a closer look at the existing equipment to determine exactly how it was operating. Tracking the temperature history as the mugs traveled through the ovens, a thermal profile was developed to aid in further analysis.

After collecting this data and showing XPRES areas for potential improvements in the performance of existing equipment, Advanced Energy conducted tests in its Industrial Energy Lab , running the product through an IR oven. From this testing, it was clear that the reduction in oven residence time could lead to higher productivity, while also achieving higher quality image transfer.

While gas ovens heat the air inside the oven, which then heats the product to initiate the decorating process, IR heats the product directly, causing the product to reach target temperature much faster, thus speeding up the sublimation process. It was theorized that this would also improve the clarity of the finished print.

"I hypothesized that different inks in the prints tended to sublimate at different temperatures," says Ewan Pritchard , project manger for the XPRES account. "Given the non-uniform heating conditions found in the current oven, this could then create a situation where one ink was just beginning to transfer, while another had already done so and was beginning to blur. I theorized that by bringing the mugs to optimum sublimation temperature faster, greater clarity could be achieved."

Tests with the IR oven bore this theory out, and plans are under way to investigate the use of an IR prototype system to help them meet their Christmas rush of orders.

"The technology assistance has been indispensable to increasing the quality and productivity of our operation," says Samir Shah, senior process engineer for XPRES.

"Their willingness to run small experiments for us at their facility enabled our operation with a low risk way to explore new technologies."

In addition to assisting with in-plant diagnostics and IR testing at our lab, Advanced Energy has assisted XPRES with a proposal to convert their coating operation to powder coating , a move that would greatly reduce the company's impact on the environment. Due to the higher transfer efficiency of powder, the changeover could also achieve long-term financial savings.

To find out more about industrial process consulting and testing services available at Advanced Energy, please contact Ewan Pritchard at epritchard@advancedenergy.org or Dan Welch at dwelch@advancedenergy.org . Or, call (919) 857-9000 .