Frozen foods are usually packed in sealed plastic bags, which go into strong corrugated cartons. For export, cartons are often stacked on pallets and stretch-wrapped before loading into the reefer.
Each layer has a job. The bag protects the food from drying and contamination, the carton protects it from crushing, and the pallet makes loading faster and more stable.
Agree every layer in writing before production. Packing faults are a common cause of arrival complaints, and they are cheap to prevent but costly to fix once the reefer is at sea.
Inner packs
Bags must be made of food-contact material that suits frozen storage. Ask for the supplier's food-contact declaration for your market. Seals must hold at low temperature, and bags should carry a lot code.
- Foodservice fries: commonly 2.5 kg polyethylene bags, though sizes vary.
- Retail bags: printed laminated or polyethylene bags in smaller sizes.
- IQF vegetables: retail bags or large bulk liners for repacking.
- Snacks: trays inside printed boxes, or bags of a set piece count.
- Flatbreads: stacks separated by sheets so pieces come apart frozen.
Cartons
Cartons for frozen food must keep their strength in cold, damp conditions. Corrugated board loses strength when it picks up moisture, and condensation forms when cold cartons meet warm air. Strong board, often 5-ply for heavier packs, and a good stacking design prevent collapse.
- Product name, net weight and number of inner packs.
- Production date, best-before date and lot number.
- Storage instruction, for example keep at minus 18 °C or colder.
- Your brand or a neutral carton, as agreed.
- Importer details if required by your market.
Pallets or floor loading
Palletised loads are faster to load and unload and suit customers with forklifts. Floor-loaded cartons fit more product into the reefer but take longer to handle, which can expose cargo to warm air. The choice affects how much fits, as covered in how many cartons fit in a 40 ft reefer.
Wooden pallets for export generally need ISPM 15 heat treatment and marking. Plastic pallets avoid this rule but may need to be returned or charged for. Check what your market and customer accept. Corner boards and strapping help keep tall pallets square during the voyage.
Common packing failures
- Crushed cartons at the bottom of stacks, from weak board.
- Split bags from cold-brittle film or poor seals.
- Missing or unreadable dates and lot codes.
- Labels that peel off in the cold because of the wrong adhesive.
- Inner bags packed too loosely, leaving air that turns to frost inside the pack.
- Cartons that block airflow because they are stacked beyond the load line.
How we help
We review bag, carton and pallet specs with the plant before production, and check marking, seals and stacking on loading day. Photos of every stage go into your file. Ask for a free sourcing review.