Gerry Ring taught papermaking at UW-Stevens Point for nearly 30 years and led its paper science department (now the Department of Paper Science and Chemical Engineering) for 10 of those years. With all that background, if there is one area of papermaking Ring would list as most important, it would be formation.
His research has shown that the key to formation is not fiber alignment but rather control of the size of fiber matrices called flocs, along with the size and shape of the pores between those flocs.
Ring says this view of papermaking represents an entirely different and more effective way of understanding and creating quality paper. He hasn't "written the book" on this new way of thinking of formation, but he has written an award-winning paper on the subject. Published in 2011, "The hyperbolic theory of light scattering, tensile strength, and density in paper" was named Best Research Article of the year by TAPPI Journal.
Ring followed that up with a 2014 paper that detailed results of an experiment he conducted on the UW-Stevens Point pilot paper machine. Using a single paper run with a single furnish to take fiber characteristics out of the equation, Ring varied setup factors such as the jet to wire ratio on the fly to demonstrate how changing the size and density of flocs affected formation.
"The first paper says that the strength is based on the average size of the pore," Ring says, "and the second paper says that the mechanical differences in the two directions are due to the shape of the pore.
"Basically, [the two papers] changed the paradigm of what you know about paper," Ring says. "Most papermakers think of paper as being a matrix of fibers. They think about the fibers being the actual structural element. Whereas, I don't. And it's based on, when two fibers bond it's a well-known fact that the surface area disappears. So, you don't have a fiber-to-fiber bond. But everybody talks about the fiber-to-fiber bond even though it doesn't exist."
Ring gets the chance to spread the gospel of floc formation twice a year in the WIST course, "Advanced Hands-On Papermaking: Formation."
"And in my course, I go through the calculations showing you how close the fibers are and how many are in actual contact with each other all the time. So, papermaking is not a matter of distributing fibers, but breaking what we call flocs. The fiber network is broken down into flocs. Certain pieces of equipment tear the networks apart and produce smaller fiber networks, smaller flocs. And then the whole process of making paper is positioning the fiber flocs."
Ring says the change in perspective has practical implications in papermaking.
"One thing you've got to stop doing is playing around with the refiner, cutting fibers," Ring says. "You've got to concentrate on the equipment that breaks flocs and stop looking at formation as just something that is pretty but as something that is integral to the strength of the paper."
In the formation class, students spend mornings in classroom sessions and afternoons making trial runs on the university's Fourdrinier pilot paper machine and then testing the paper made.
"What I think is truly unique about our paper machine is that we can isolate the fiber factor," Ring says. Commercial papermaking machines can't make the kinds of setup adjustments on the fly that can be made on the pilot machine, and students gain immediate insight into the impacts of changes made. "The fact that we can setup on-the-fly jet to wire ratio is, I think, very powerful."
Ring says that papermakers typically think of formation as an appearance property when in fact formation is a strength property.
"I'm saying, if you don't form it correctly, it won't perform," Ring says. "Formation is the number one fundamental paper property."
The next WIST course on formation with Gerry Ring is set for October 10-11. See below for more information and links to register.