If your cardboard box has a rounded number code (usually in the bottom left corner), don’t guess what those codes mean. They could make all the difference in the world by helping a packer determine whether that particular box is going to work properly.
Reading them takes less time than it does to write an email. And reading them will help prevent the wrong box from being packed with a very heavy product.
Those stamps are usually referred to as “box makers certificates”. They usually include information such as the name of the manufacturer, type of walls, maximum size limit and top weight. Not all stamps are alike, so take the time to read each line instead of making assumptions based on their appearance. The weight listed on the stamp is actually for the total package including the product, packing materials, tape and the box itself.
There might be a letter designation on some stamps that says ECT. ECT stands for Edge Crush Test. Edge Crush Test shows how well the material will withstand pressure applied to its edges. As packages are stacked, the lower packages must bear the load of the upper packages. There may also be a Burst Test designation on the stamp. That tests another form of strength. Do NOT treat these numbers as equal.
Some new packers get confused about what the size limit means. Size limits relate directly to both the box and the strength rating of that box, not necessarily how carriers charge per pound for larger shipments. Before shipping out a long or wide product, check the current regulations regarding the specific shipping method being used instead of just relying upon the size limit stated on the packaging.
No matter how high of a strength rating is given to a box, it still doesn’t matter if that box is poorly taken care of. Any deep cuts, moisture damage, ripped flaps and crunched edges to a box can significantly reduce its original value. A box that has been previously shipped may not perform exactly as one would expect from a brand-new box. Always inspect used cardboard boxes from every angle prior to loading products into them.
That little stamp also doesn’t guarantee that anything you’re shipping will arrive safe and sound either. Proper distribution of weight, enough empty space to allow adequate filling and solid taping to seal each flap can greatly affect performance. Items requiring special protection (sharp items, breakable etc.) may require additional support. When shipping something that requires extra handling, consult with the manufacturer/seller or carrier which rating best applies to that specific shipping requirement.
Show employees where to find the certification and explain the key points. Consider keeping a sample near the packing station with the rated capacity and strength markings highlighted. This simple reference tool will greatly decrease errors related to identifying similar appearing cardboard boxes. What appears to be nothing more than an unassuming stamp at the bottom may provide valuable guidance to your packing staff before adding labels to the top.