The PPEC persuaded the Liquor Control Board of Ontario (LCBO) to modify the rules to allow suppliers the option of using the edge crush test (ECT) as an alternative to the burst strength (aka Mullen) test to assess the delivery performance of corrugated packaging.
The trade association said the move is “long overdue” and it “opens the door to producers of recycled board”.
The Mullen burst test is a measure of the force required to rupture or puncture corrugated board, according to Campden BRI.
“This force is indirectly related to the pack's ability to withstand internal and external forces and protect its content during storage and distribution.
“Edge crush test is linked to stacking strength. It is a measure of the edgewise compressive strength of corrugated board.
“A small piece of a carton is placed between two platens and compressed perpendicular to the direction of the flutes.”
Increasing concern
John Mullinder, PPEC executive director, said industry had become increasingly concerned over the reliance on the Mullen test, especially when the wine and liquor sector had started fining suppliers for not meeting its Mullen specifications.
“To our knowledge, the LCBO was the only major wine and liquor retailer in the world still using the Mullen test as a barometer for box failure and/or container breakage. Everyone else had moved to ECT.”
Method trials
The council started pilot laboratory trials using the measuring standards of the International Safe Transit Association (ISTA).
Various types of boxes and glass bottles were shaken, dropped, and slammed into hard surfaces to see how they performed.
The findings showed that the Mullen test was not a good predictor of actual box performance, regardless of whether it was made from kraft or recycled material, said the PPEC.
It also highlighted that any new performance-based testing procedure should include all the elements of the package (the outer box, partitions, and the container inside).
The PPEC said in one series of tests, the box with the highest Mullen (and the most likely to be the best performer according to LCBO specifications) was actually the worst performing box.
PPEC set up a technical committee two years ago and began to work with the LCBO to drop the Mullen test, which it has used for more than 20 years, or allow ECT to assess the packaging.