Putting Corrugated Boxes to the Test at ACC

In the late 1970s, some U.S. paper companies began to mix some recovered and repulped OCC (old corrugated containers) into virgin liner. Since then, some paper mills, such as mini-mills have run on 100% OCC. This is usually called ECT. (Most corrugated boxes ordered from catalogs are made from virgin kraft paper.)

When we consider what to test when corrugated boxes are being made, it helps to look first at what properties or qualities we want in the finished box or container.

In general, there are four things that all ACC corrugated boxes should have:

  1. Favorable Appearance: this includes sharp, clear printing with uniform print coverage, especially for bar codes and product or company identification, and exact panel dimensions with crisp scores, slits and s, ots.
  2. Protection for whatever is shipped or stored in the box.
  3. Compression strength to allow the filled container to be stacked for storage or shipping.
  4. Durability: the ability of the container to retain the above qualities over a desired period of time.

What should a corrugator or box plant test for?

Appearance is a highly subjective quality and is often judged by an expert eye. Strength properties are more quantifiable and the following box and combined-board tests provide the core for evaluating box construction and strength.

  • BCT (Box Compression Test)
  • ECT (Edge Crush Test)
  • Flexural Stiffness (Stacking Strength)
  • Pin Adhesion (Strength of Adhesive Bond)
  • Flat Crush (Flute damage)
  • Caliper (Thickness)
  • Burst (Mullen Test)
  • STFI or Ring Crush (at the mill)

For example, to demonstrate the strength of bonding, at your next opportunity, perform your own pin adhesion test on several commercial boxes by peeling the liner from the medium. You may be surprised at the number of boxes that demonstrate little or no fiber pull. This is a simple boxmaker’s guide to corrugator bonding with a marginal relationship between pin adhesion strength and ECT board.

We offer lab analysis. Most of these tests are performed for us in the professional laboratories at our mills or independent labs, with not cost to you, our customers.

Submit a quote today for the custom corrugated shipping boxes and other stock corrugated products you need. Or, contact CalBox Group for more information.

 
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