Does your corrugated measure up?
By David Luton -- Modern Materials Handling, 7/1/1998
Corrugated shipping containers, or "cardboard" boxes, as they are more commonly called, have been the dominant form of exterior packaging for decades. Their "sandwich" construction provides low cost cushioning and effective product protection.Historically, in designing corrugated containers, warehousing's needs were secondary to transportation's re-quirements-to limit the potential for product damage claims-be-cause of the influence coming from major transportation regulatory bodies.
To protect themselves, carriers set rules defining minimum construction requirements-bursting strength, for example-for shipping containers (see sidebar). In the past, there were no corresponding standards pertaining to container performance in warehousing.
Today's warehouse requires a measurement standard more suited to the ability of a specific container to safely bear a load without damage to the container or to its contents. (Warehouse product stacking heights have greatly increased, of course, since the standards were first developed.) And, as noted in my May column, the increasing use of flexible inner packaging greatly increases the need for a stacking height standard. Fortunately, one exists: the container's vertical compression strength.
Compression strength is a function of both the quality of the linerboard medium and the quality of boxmaking. Compression is measured by the use of a new standard called ECT, short for Edge Crush Testing. The standard was accepted by the American Trucking Associations in 1991 and by the railroads after a six year trial period in 1997.
The ECT standard provides the materials handling professional with a classification system more relevant to warehouse needs. There are also new interim categories which will provide a more complete range of containers to meet these needs.
The other major benefit of using the new ECT standard is the opportunity it affords to achieve material savings by use of high compression linerboard. In addition to improving performance, up to a 10% savings in linerboard is anticipated over time. For example, in the single wall 200 lb test container category based on the historic mullen standard, 37 lb high compression liners may be substituted for the traditional 42 lb liners.
Corrugated standards a brief look
With an eye to holding down freight damage, rules set 70-80 years ago, by the railroads, initially, and later the trucking industry, defined corrugated container manufacture in North America. Each box required a certification stamp.
Until recently, these rules remained relatively unchanged.
But standards reflecting the damage concerns of transportation rely upon two factors: The basis weight of the facing linerboard used to construct the container and the bursting strength of the walls of the container.
Bursting strength is an important and understandable test for the likelihood of freight damage. But its relevance to the needs of modern warehousing is indirect, at best. Over the decades, warehouse product stacking heights have gone way up.
For each category specified, the maximum weight of the box and its contents, and the maximum box dimensions (i.e., the length, width, and height added together) result in a standard classification code number.
There are no other articles related to this article.Talkback
Related Content
Related Content
Sponsored Links
View All Blogs
