Rod Coating vs. Flood Coating

August 2, 2017

Geordie asks,

We’re considering some new equipment and looking for some information on flood coating versus rod coating.

If I were looking for new equipment I would probably lean toward rod coating. In my opinion rod coating is more effective and accurate than flood coating. Rod coating provides a very wide coating weight range. They also allow much greater precision in coating weight control and are typically much easier to operate. The rod coating process also provides superior cross machine coating uniformity as compared to flood coating.

Most modern rod coater designs make very easy and quick to change the coating thicknesses as well. So if minimizing changeover time is important to you that may be another advantage to rod coating.

— Ralph


Just how many corrugators are there?

August 2, 2017

Ron asks,

I’m doing some basic research on the corrugation market. My questions are:

  • How do I find out how many corrugators (machines) there are Worldwide by region?
  • And is there a way to know the width of each of the devices, such as over 2 meters, under, etc?
  • I’m also trying to answer the same question for Asitrades and Laminators.

That is a very tough question, especially from a global perspective! We know that the 432 +/- corrugators in the US are mostly 98″-110″.  Specs would be about the same in Europe and Canada.  Mexico is modernizing and we’re seeing 2.5 – 2.8 meter machines going in.  China is spending the capital.  Australia and New Zealand are modern. The rest of the word is, well, the rest of the world.  I would start by getting in touch with the corrugator manufacturers like BHS, Fosber, Agnati, etc. perhaps they can provide a worldwide overview of corrugator footprints. For Asitrades try touching base with Bobst. Most recently they are in the 65” range, but one of the newest located on the US East Coast is an 87” machine.

Industry publications often offer buyers guides, or directories of equipment suppliers. You may want to research some of those for lists of equipment suppliers. AICC’s member directory found on also provides a means to search equipment suppliers (Associate Members:) that may be able to provide information.

— Ralph

Do Board Grade and Flute Size Affect Pin Adhesion

August 2, 2017

Desi asks,

Do box grade and flute size have an effect on the Pin Adhesion Test? Also, I know that the double backer bond is stronger than the single facer so how do we know which side failed first in the normal pin adhesion test since no side is being held firmly to the base?

There is some thought that at the lower grammages and lower caliper the liner is not “rigid” enough to support itself or lay flat enough for the pins to do an adequate job of breaking the glue line. I have seen pin targets as low as 42 for 23# C flute.

The Pin Adhesion test is selective separation. The weakest point will be the first to give. In this test one side is supported while the other is tested, therefore sides should are tested separately. Using the TAPPI method, it should not be possible to test both sides in the same test.

If you search “pin adhesion” on this site you may find more helpful information.

— Ralph

GMI Certification for Corrugated Converters

June 15, 2017

John asks,

We recently had a customer ask if we were GMI certified. What do you know about this, how long does it take to receive the certification and do you know any Independents that have GMI certification?

Our associate Scott Miller at BCM Inks helped us with some background and industry knowledge on the subject.

The GMI certification awarded by Graphic Measures International (gmi), a St. Louis Missouri based company that certifies, monitors and measures the performance of packaging suppliers with a main focus on positioning plants to meet graphic standards of quality and color. Global brand owners often require this as a measure to help them maintain a consistent appearance of their brand.  Through training, process development, certification and continual monitoring GMI ensures plants are maintaining and running to industry standards.

The GMI certification process is rather in-depth and can take 3 to 5 weeks. The process measures everything from light booths to actual print samples. Many brand owners who are quality and color critical will only qualify or use printers who are GMI certified. This gives the brand owners the confidence that the printer has process control in place to provide repeatable results that will meet their global standards.

According to Scott he can name any [particular] corrugated printer who is GMI certified. “However, I see their certification stamp on a lot of light booths when I’m in plants.”


— Ralph