Guide
Poly liners for gaylords
A poly liner is a bag inside a gaylord. It keeps fines in and moisture out, and it is the cheapest upgrade a box can have.
A poly liner is a plastic bag that lines the inside of a gaylord. It keeps fine or flowable loads clean, keeps a little moisture out, and makes unloading cleaner. It does not add strength to the box. Ask for one when the load is a powder, a pellet that sheds dust, or anything you do not want in the corrugated.
| Load | Liner? | Why |
|---|---|---|
| Powders and fines | Yes | The flaps never seal a powder; the liner does |
| Pellets and regrind | Often | Keeps dust and moisture off; easier to empty |
| Produce | Rarely | Fruit wants air; ventilation matters more |
| Metal parts | No | Dense parts tear a liner |
| Scrap for recycling | No | Liners complicate OCC |
Liners and the cold
A liner helps on a dock because it keeps condensation off the load, not because it keeps the box dry. Condensation forms on and in the board when a cold box moves into warm air; a liner shields what is inside. AICC warns that moving corrugated between temperature zones causes internal condensation or moisture migration.
Liners and recycling
A liner has to come out before the box goes to OCC. Pulling it is quick; leaving it in complicates recycling. Say on the request whether liners are still in.
What not to expect
- A liner does not make a used box food-safe. Food-contact reuse depends on the buyer's own rules.
- A liner does not strengthen the box or add stack height.
- A torn liner is a failed liner: check before you load.
See lids and liners, slip sheets and full and partial bottoms.
Choosing a liner by load
Liners come in different thicknesses, and the right one depends on what is going in. Fine powders and pellets want a thicker film that does not tear when the load settles. Light parts and packaging want less. A liner that is too thin splits at the corner and spills the load into the dock; one that is too thick is a cost without a gain.
Fit matters as much as thickness. A liner that is too small cannot be folded over the top, and a liner that is too large bunches in the corners and traps air. If you are buying a mixed lot of boxes, tell us the footprints and the heights, and the liner size can be matched.
Finally, ask who removes the liner. A box that goes to recycling should lose it first. If your team will not do that, say so, because it affects which grade the box can be sold as.
When to skip a liner
Many loads need none. Parts that do not shed, sealed bags and bundled goods are fine in a plain box. A liner adds a step at the fill end and another at the empty end, so add one only for a reason you can name.
Questions, answered
Do gaylord liners come with the box?
Not by default. Ask for one and say what the load is.
Sources and last reviewed
Facts on this page were last reviewed 2026-11-11.
- AICC: strengthening corrugated against cold weather: Industry guidance on cold weather, condensation between temperature zones, and strength lost over 90 days under load.
- Container Exchanger: the gaylord box guide: A reseller's plain-language guide to gaylord sizes, walls, capacity ranges and bottoms.