Sanpo-yoshi Communication

Printing Column] Bitter Memories of Silver Foil Paper

At Marushin, we have banned the use of foil paper—which is aluminum foil laminated onto creased cardboard—and instead recommend vapor-deposited foil paper, which is PET paper coated with silver. This is because we have a very “bitter” memory associated with it.

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It was toward the end of the year a few years ago. It happened on a Friday in the middle of the month.

I immediately checked the retained samples at our factory. However, even when I bent the lid of that box, it didn’t break. Upon arriving at the customer’s warehouse, I asked…
When I checked the boxes in question, I found that—to my surprise—the creases at the base of every single box had split wide open when the lids were closed, and on top of that, the split aluminum sections were curling upward.

The room temperature at the Marushin factory, where the boxes are manufactured, is about 25 degrees. However, since it is winter, the temperature inside the customer’s warehouse is around 5 to 10 degrees. The cold caused the aluminum surface to contract, and when the lid was closed, the chilled foil section was pulled, causing it to crack due to a lack of strength.
So I thought, “Why not try stretching it out again?” I used the end of the ballpoint pen opposite the tip to firmly trace along the crease, and the cap closed securely without breaking. It seems that tracing it a few times generated some frictional heat, which caused it to stretch.
The next day, the entire staff pitched in to carry out the repairs. However, we discovered that there was additional inventory, and when we moved it to the storage area, the temperature there was below 0 degrees. As expected, even when we performed the same repairs, the items still cracked.
We're short on boxes for our New Year's products! This is a major crisis. We offered our customers alternative solutions and managed to make it work in the end.
Since then, Marushin has banned the use of aluminum-based foil paper, which can crack at low temperatures. Looking back, it’s a bittersweet and nostalgic memory.
I’d like to express my gratitude to the customers who taught me so much and to everyone who helped with the repair work.