Archive for the ‘Testing and Specifications’ Category

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

What is the difference between ECT and ECV?

June 9, 2017

Charles asks,

What is the difference between ECT and ECV?

ECT (Edge Crush Test) is the testing method. ECV (Edge Crush Value) is the actual outcome or reported result of the Edge Crush Test. ECT is a measured in pounds per lineal inch of load bearing edge. Though it may sometimes be reported as ECV or lb/in it is typically reported or listed as an ECT value such as 23 ECT.

ETC has widely replaced the use of the Mullen test as ECT is considered by most as a more accurate test of the stacking strength of a corrugated box. It measures the edgewise compressive strength of a corrugated sample on an axis parallel to the sheet. Mullen, on the other hand, measures the bursting strength of the face of the corrugated sample, or on an axis perpendicular to the sheet.

– Ralph


Moisture Test Comparison MRA vs. non-MRA Box

May 24, 2017

Steve asks,

Would you have or could you please direct me towards any testing data/statistics on a box with MRA vs. a non-MRA box?  I would like to see what kind of improvement it shows in a moisture-related test.

The dimensions, flutes and composition range (very small to large boxes; B/C, E/B, and B flutes; 32ECT to 71ECT), and I don’t have much info on supply chain.  A customer just looking for any testing data that he can get on MRA to demonstrate that it does improve performance in moisture.

For assistance with answering this question I reached out to Clayton Clancy at Kruger. He has provided this this detailed study on stacking performance when using water-resistant adhesives, complied by the Institute of Paper Chemistry, which high-lights paperboard performance improvements when using WRA additives. He cautions that there are varying terminologies used when discussing water resistance such as (MRA, WRA and WPA), with that in mind I hope this will be helpful.

— Ralph

German to US Board Equivalents

March 22, 2017

Luke asks,

Quite often, I receive requests to spec out a box that was originally designed in Europe– most often Germany or Belgium. I have had a really hard time finding US equivalents to some of the board combinations used “over there”, both in flute and paper weights. What we struggle with most is the board codes (e.g. PLK 140/ WS 115/ TL 140 or TLW135/WS70/TL135, ZNNW43).

Is there a resource out there somewhere that I can utilize to best determine a US analog for flute combo/paper weights?

To answer your question about your specific combination above it would be coated liner 29#/ waste based 23#/Testliner 29# and test liner white 28#/waste based 14#/test liner 28#. I have no idea of the ZNNW 43 name. However, take a look at these two documents. They may give you the information you need. Alternative Requirements Table, Transport Quality Requirements.