On New Year’s Day, The University of Notre Dame’s football stadium was converted into an outdoor hockey arena for the 2019 Bridgestone NHL Winter Classic®. With the Golden Dome and Touchdown Jesus in the background, the Boston Bruins defeated the Chicago Blackhawks, 4-2, in front of over 76,000 fans. If you were watching the game on TV, you saw a fun side story about a new technology being introduced at this game. The official game pucks featured a new coating technology that allows the pucks to change from purple to clear when the puck’s temperature is above freezing. This provides a visual indication to officials that the puck should be replaced.

According to Dan Craig, NHL Vice President of Facilities Operations, “Hockey pucks are made of vulcanized rubber, and glide smoother and faster when frozen. Freezing a puck eliminates bouncing, and game officials closely monitor the puck for temperature changes that affect performance while in play. A coating that changes color when the puck is above freezing will more accurately alert the officials that it is time for a replacement.”

The novel thermochromic coatings are supplied by PPG. The coatings meet the NHL’s requirements for withstanding game-environment impacts and low temperatures without impacting adhesion. The coating is dispersed into an ink system and screen printed directly onto an official NHL game puck. The coated pucks will be tested at NHL events during the 2018-19 season and will be further evaluated for broader use in the future.

“Working closely with our technology partners, LCR Hallcrest and QCR Solutions Corporation, we’ve been able to offer a smart and elegant solution to a problem that can significantly impact game play,” said Alicia Cafardi, PPG Senior Marketing Communications Manager, Industrial Coatings. “The custom dye pigment that changes color with temperature was developed specifically for this application on hockey pucks, but the solution represents an opportunity for other applications where an easy, visual reference could serve to improve the performance or use of an object.”  

PPG is actually the official paint of the NHL. The company’s paint products and coatings have a presence throughout professional hockey, protecting and beautifying hockey arenas throughout the United States and across Canada. In addition, the company’s coatings help to reduce chips and wear on hockey equipment, including goal posts.

As a Notre Dame grad, and 35-year resident of the suburbs of Hockeytown, I really enjoyed learning about this creative new technology and the venue for its introduction!