Why a consumer wants, and how a manufacturer produces folding boxes that crease without cracking.
Obviously you want folding paperboard box that houses your product to look and function as well as it is possible.
Folding paperboard boxes are made to fold at creases. No kidding right? There are in my mind however a couple of things regarding creases that I think would be of interest to people who purchase folding boxes.
Central thought in my mind is that a good crease does not crack the paperboard. A cracked crease ruins the graphics. Typically boxes one purchases are going to have creases that fold without cracking. Hopefully you will be interested as to how this is accomplished. The paperboard used to make folding boxes consists of layers of fiber. When the board is struck by the die the cutting rules cut, the creasing rules both create a “U” along the crease and break the bond between the layers of fiber along the crease. This accomplishes two things necessary for the crease to fold without cracking.
One the “U” shape on the printed side stretches the top side so that when paperboard is folded there is slack that can be taken up without breaking the top side. You may ask why, and it is because as the board fold the edges of the panels pull slightly away from each other.
Secondly, by breaking the bond between the layers of fiber that make the paperboard the board moves out creating a “bead” along the inside of the crease. If the material would not be pushed out it would create a force that would break the crease on the top side as putting a stone in a hinge of a door would break the hinge when you closed the door.
To create a “U” and to break the bonds of the fibers requires that your crease is of the correct height, and that the “channel” the crease pushes the paperboard into, is of the correct width. The type of paperboard and the thickness of the paperboard are used to calculate the proper settings.
Gary R. Gross