Tape has a finite working life
A BOPP roll is not inert. Over time the adhesive can migrate into the film, the film can yellow, and the layers can bond to each other so tightly that the roll will not unwind cleanly. Most manufacturers work to a twelve month shelf life from production when the roll is stored in reasonable conditions, and that figure drops sharply in a hot warehouse.
The two environmental enemies are heat and direct sunlight. A pallet stored against a south-facing window or under a translucent roof can reach 50C in summer, which softens hot melt adhesive and accelerates ageing in acrylic grades. UV also degrades the polypropylene film itself, making it brittle at the edges.
Storage rules that pay for themselves
Keep stock in a dry, shaded area between 5C and 30C with relative humidity under 60 percent. Store cartons on pallets rather than directly on a concrete floor, because concrete wicks moisture into the board and then into the roll edges. Leave space between stacks so air can move.
- Rotate stock first in, first out
- Keep rolls in their original cartons until use
- Avoid stacking above 1.8m
- Do not store near solvents or printing inks
If a roll has been in storage for a year, test it before releasing it to the line. Apply a strip to your own board, leave it overnight at ambient temperature and check the edges. That five minute test is cheaper than a pallet of cartons arriving open.
