Square cases are the key to getting your cases to pack, stack, and palletize better. That’s not a ground breaking revelation. In fact, many companies invest in a case erecting machine to help achieve this goal, and we’ve written a lot about case erectors in the past.
What can sometimes be overlooked, however, is the importance of not just erecting cases but also sealing them.
The integrity of the whole
So let’s start out with what makes a good case. Firstly, it’s important to understand the purpose of a case. Form follows function, and this is true for ideal cases.
Cases are stacked, one on top of another and side by side, to create a load that can be wrapped on a pallet and transported. The ideal case, then, needs to be uniform in its dimensions and construction with the other cases it will be stacked with.
Picture stacking building blocks into a tower. If all the blocks are exactly the same size, the tower is stronger and sturdier than if you build with blocks of varying size. If the blocks you chose are different sizes, your tower won’t be able to go as high without falling.
The same principle applies to the cases that make up a load. When cases are uniform in construction it allows for vertical alignment, and therefor strength, of the load. In fact, cases that aren’t vertically aligned lose 30 percent of their stacking strength.
And, because cases are 3D objects, this means that their tops need to be as flat and uniform as their sides. To go back to the building block example, imagine if the tops and bottoms of some of the blocks you are building with have lumps or raised areas. These blocks won’t sit flush with the blocks above or below them and, again, you won’t be able to build the tower as high before it becomes unstable and falls.
Cases with horizontal, flat tops and bottoms stack better without leaning, maintain a vertical alignment, and are stronger.
How can a multi-stage flap system can help?
One of the things that makes a good case sealer is a good case erector. It’s hard, after all, to seal the tops and bottoms of a case flat without square sides. In order for the tops and bottoms to become horizontal, the case must already be square from the case erector.
A multi-stage flap system ensures that the case gets folded correctly.
For an example of this watch the video below, and pay attention to the folding of the front flap. A two-stage flap folding process breaks the score and relies on the plow to push the flap down. After this process, either the glue nozzle glues or the tape dispenser tapes the flaps closed.
The glue or tape matters
Another aspect of a good case sealer is the way it handles the sealant itself.
If glue is being used, the pattern it is applied in should be adequate to seal the case but not excessive. Meaning that there shouldn’t be so much glue that it’s oozing out of seams or distorting the corrugated.
Placement is also important for the tape. When tape is being used, however, it’s good if the tape is easy to change.
Remember, good case sealers have:
- Positive control of the front and trailing flaps
- Plows that close the major flaps
- Repeatable, reliable performance
- Precise glue application/easy to change tape