Substrates

Our paper-based markets are indeed converging; this includes rigid box, folding carton, and corrugated. At the 2018 Spring Meeting in Phoenix, the Association held a three-hour panel discussion moderated by your own Tom Weber and me, with five well-known and experienced companies in the area of small-flute corrugated and its application in the rigid and folding carton markets. Special thanks to Darin Jones of Pacific Southwest Container; Michael Drummond of Packrite; Tony Reilly of Schwarz Group; Dave Moreno of Greif; and Sharlan Kozak of CEL Chemical for their participation.

Looking back, via document search on my computer, it appears that there have been at least eight articles or webinars on “substrates” during the last 12 years. We are often confused by this term, which becomes a generic term that applies to paperboard, solid beached sulfite, coated recycled board, uncoated recycled board, solid unbleached sulfite, kraft linerboard, recycled linerboard, coated white-tops, and a host of others.

Cooperative research and articles for the past 20 years have focused on structural comparisons of the different grades and print image reproduction differences on the surface of the different materials. What we do have in common with the structural aspects of the different substrates remains the same in that we are not typically building to containmentbut to compression elements best described as stiffness or bending resistance. These are measured with TAPPI-approved testing protocols, except for one specific test that came from the beverage carrier market, and that is corner crush and block compression. (On a side note, if you are interested in the loss of box performance from score cracking, you now have access to a methodology that can measure that concern. We are developing a white paper on the entire issue of score cracking, and it is scheduled to be published soon.)

In regard to printing, be very aware that every substrate is uniquely made and has its own DNA profile. Even those within the same category will not perform the same. I very much enjoy working with one specific litho label printer who, over the years, has been very open with sharing his technical expertise and always answering my questions. He has noted that, in his process and in meeting his customers’ expectations, he is indifferent to four of the five C1S products that are on the market, but he cannot get that fifth substrate to perform. So, four out of five are viable suppliers, and the fifth one is not able to qualify.

Digital presents an entirely new challenge. All that we have known about substrates, anilox rolls, inks, plates, and printing presses goes away with this technology. And the technology is not all the same. While digital can overcome someit is still subject to all the corrugated vagaries of scoring, slitting, dust, warp, cracking, and washboarding. The February 2018 seminar hosted at SUN Automation discussed these and many more.

Valmet, one of the last remaining manufacturers of papermaking equipment, has announced it has taken paper-making across the web moisture profiling technology and developed a scanner for corrugators. I have not personally experienced one, but it should be very promising, even though we have seen earlier uses of similar technology in corrugated production.

So, please let me encourage you, as you attempt to move up the image reproduction scale, to reduce variation, remove costs, improve productivity, and create a better brand. Connect with Tom and me regarding your projects. We are here to save you heartache and pain.

Ralph Young is the principal of Alternative Paper Solutions and is AICC’s technical advisor. Contact Ralph directly about technical that impact our industry at askralph@aiccbox.org.