Corrugated boxes lose strength before they ever get packed. A box that tests at 32 ECT on the day it leaves the plant can perform well below that after a few months in a damp corner of a warehouse, stacked wrong, next to a loading dock door. The same goes for tape that has baked on a radiator-side shelf or stretch film that spent a summer in a hot trailer. If you have ever had a box crush on a pallet or a tape roll that would not stick, the storage conditions are the first place to look. Here is how to store packaging supplies so they perform the way you paid for.
Why Humidity Is the Biggest Threat to Corrugated
Corrugated board is paper, and paper absorbs moisture from the air. As the fibers take on water, the board gets softer and the fluting loses its ability to hold a load. Box manufacturers rate strength at standard conditions of about 50 percent relative humidity. Push the humidity up into the 80s and 90s and stacking strength can drop by half or more. That is not a defect in the box. It is just how paper behaves.
Chicagoland makes this harder than most regions. Summer air off the lake is humid, and a warehouse with a dock door open all day is effectively outdoors. In winter, heated spaces get very dry, which makes board brittle and prone to cracking at the score lines. Then spring and fall swing back and forth. Boxes that go through several of these cycles get weaker each time.
How to Store Corrugated Boxes Correctly
- Keep bundles off the concrete floor. Concrete wicks moisture. Store flat box bundles on pallets or racking, never directly on the slab.
- Store them flat, not on edge. Bundles stood on end put weight on the scores and warp the board. Flat stacks with the weight spread evenly keep boxes square.
- Leave the bundle straps and wrap on until you need them. The strapping keeps the stack tight and the wrap slows moisture pickup.
- Keep boxes away from dock doors, exterior walls, and sprinkler risers. These are the dampest spots in most buildings. The middle of the warehouse is usually the driest.
- Rotate stock first in, first out. Put new bundles behind the old ones. A bundle that sits at the back of a rack for a year is a bundle that fails.
- Do not stack bundles too high. Bottom bundles under a tall stack take a permanent set. Follow the manufacturer’s stack height if one is printed on the bundle, and otherwise keep it reasonable for the board grade.
If you are running custom sizes or printed boxes, storage matters even more, because a damaged run cannot be replaced from stock overnight. Our custom boxes and bulk orders page covers how we handle larger runs and staggered deliveries so you are not warehousing six months of boxes at once.
Tape: Heat and Cold Both Cause Problems
Packing tape adhesive is sensitive to temperature. Hot melt tape stored in a hot area, like a mezzanine near the roof deck in July, can get gummy and pull off the roll with the adhesive stringing. Stored too cold, the same tape gets stiff and loses tack, which is the usual reason tape “will not stick” in a cold warehouse in January. Acrylic tape has a wider tolerance but still performs best applied near room temperature.
- Store tape in its case, in a climate-controlled area if you have one, and bring only a day or two of supply out to the packing line.
- Keep cartons out of direct sunlight. UV degrades both the adhesive and the film backing.
- Use older cases first. Tape does have a shelf life, and most manufacturers recommend using it within a year or so of purchase.
Stretch Film and Poly Bags
Stretch film relies on its cling layer and its ability to elongate. Heat degrades both. A pallet of film left in a trailer or against a sun-facing wall will lose cling and tear more easily on the wrapper. Cold is less damaging, but very cold film applied by hand tends to break at lower stretch, which means you use more of it. Store film cases upright as shipped, out of sunlight, in a moderate temperature, and let cold rolls warm up before use.
Poly bags are more forgiving, but they still should not sit in heat or sunlight. Dust is the bigger issue. Open cases of bags on a shelf collect dust and debris that ends up inside the bag with your product. Keep cases closed until they go to the line.
How Much Should You Keep on Hand?
The best way to avoid storage damage is not to store more than you need. Many businesses buy large quantities to get a better price, then lose part of that savings to crushed, warped, or stale stock. With a local supplier, you do not have to choose between price and freshness. KMS Distributing keeps stock in Prospect Heights, and most in-stock orders placed before noon deliver the next business day anywhere in Chicagoland. Orders over $1,000 ship free. That lets you hold two to four weeks of supply instead of six months, keep it in a good spot, and reorder on a schedule.
A quick storage audit is worth an hour. Walk the warehouse, find where boxes, tape, and film actually sit, and move anything that is on the floor, near a dock door, or in the sun. Then check your oldest stock and use it first. If you need to restock, you can browse our full line of boxes, tape, film, and supplies at kmsdistributors.com/Shop.
Need boxes, tape, or film that arrive fresh and ready to use? Call KMS Distributing at (847) 630-7502, email orders@kmsdistributing.com, or browse 20,000+ products at kmsdistributors.com/Shop. Free Chicagoland delivery on orders over $1,000.
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