Did you know one of the most important aspects of a high-quality printed document is a high-quality sheet of paper? Just ask Shannon Gittermann, a process engineer at our Johnsonburg Mill. She leads the effort to optimize sheet formation to ensure premium printing outcomes.
One of the biggest challenges to achieving a clean and uniform print job is picking — the appearance of small white specs in the printed colors. Picking happens when tiny bits of the sheet pull away as color is laid during the print process.
“A lot of our customers use our high-quality paper for printing forms, brochures and flyers,” Gittermann says. “We want to ensure they always get good solid color when they print, so we have a process to test for picking and help guard against it.”
Our technicians use the wax pick test, which uses calibrated wax sticks to evaluate surface strength. The Domtar mills that produce Husky, Lynx and Cougar paper use this test as a predictor of offset printing cleanliness.
“We heat the wax so it will start to melt,” Gittermann says. “Each stick of wax has different adherence qualities. We apply each stick to the paper at a consistent pressure and let it cool for 20 minutes. After the wax sticks are cool, we pull them back and inspect.”
Technicians look for any disturbance in the sheet, such as rupturing of the paper surface, fibers sticking up from the paper surface or fibers sticking to the end of the wax stick after it is removed. “All of these results indicate the surface strength of the paper is lower than the adhesive value of the wax stick,” says Lori Slovik, Domtar’s technology manager for printing and publishing papers.
Slovik says engineers at our mills rely on these and other tests to assess manufacturing process variables that could affect the surface strength of our high-quality paper.
“When we do trials at our paper mills, we hold ourselves to a very high standard; if our paper holds up to the rigors of our own testing, then we have a high level of confidence it will also perform well with our customers in the field,” says Bill Edwards, vice president of manufacturing for communication papers.
There’s a lot of science, technology and functionality testing to ensure our high-quality paper products will perform as expected. So the next time you see a flyer or marketing brochure, remember that it’s much more than “just paper.”