PETG freezer packaging is one of those applications where the material datasheet and the freezer floor disagree. Room-temperature impact figures look generous; at minus 18 C the same tray can crack on the corner from a 600 mm drop.
A ready-meal producer in the Netherlands switched 1.2 mm PETG trays into a minus 22 C line and lost 3 percent of packs to corner cracks in the first month, all during pallet handling rather than in the freezer.
PETG freezer packaging gauge and format
- Shallow trays to 40 mm: 0.8 mm, low fill weight
- Standard frozen meal trays: 1.0 to 1.2 mm
- Deep or heavy packs: 1.5 mm, high-impact grade
- Below minus 25 C: validate a high-impact grade, or change polymer
Gauge selection follows the fill weight and the drop height, not the shelf appearance. A 1.2 mm tray carrying 400 g survives a 600 mm drop at room temperature; at minus 18 C the same tray may not, because the polymer stiffens and energy absorption drops.
The cold drop test that settles the question
Freeze a full pallet of packs to the real service temperature for 24 hours, then drop cartons from the height used in your distribution trial, at the temperature they will actually be handled. Cracked corners appear within one pallet and tell you more than any datasheet.
Sealing is done warm at the filling line, so the cold room does not change the seal. What it changes is peel behaviour in service: a film that peels cleanly at 20 C can shatter or delaminate at minus 18 C. Validate the pack frozen.
Condensation is the other cosmetic issue. A cold pack in a warm retail case fogs, and a fogged lid reads as poor quality. A slightly matte film and a controlled case temperature reduce it.
Where the pack also needs a food-contact statement, the PETG FDA compliance guide covers the grades, and the PETG packaging guide covers the sealing and print side.
Thickness tolerance matters more in packaging than in glazing, because a thin pack fails a drop test that the drawing said it would pass; the PETG thickness tolerance guide explains why.
Send your pack format, fill weight and freezer temperature to oversales@rpplexiglass.com for a PETG specification.
Frequently Asked Questions
Is PETG suitable for frozen food packaging?
It is suitable down to about minus 20 C in most formats, but impact strength falls noticeably below that. For deep-frozen packs at minus 30 C, a high-impact grade or a different polymer is usually the safer choice.
Why do frozen PETG trays crack at the corners?
Low-temperature embrittlement plus wall thinning at the base radius. A tray that survives a drop test at room temperature can fail at minus 18 C; the test has to be run cold.
Can PETG be sealed with a lidding film in a cold environment?
The seal is made before freezing, at the filling line, so the cold room does not affect the seal itself. What the cold chain affects is the peel strength in service and the film choice, which must be validated frozen.