Airflow Through Palletised Loads: Cooling, Condensation and Stability
Manufacturers put a lot of effort into controlling product temperature through cooling tunnels, cold stores and refrigerated transport.
But one part is often overlooked:
what happens after the pallet is wrapped.
For many ambient products, solid stretch film is the right choice. But where a product is still warm, still cooling, releasing moisture or continuing to respire, the way the pallet is wrapped can affect what happens next.
Why airflow matters
Cooling is not simply about placing a pallet in a cold room.
Cold air needs to reach the product and heat needs a route out.
If airflow is restricted by cartons, pallet configuration or solid stretch film, cooling can take longer and temperature differences can develop through the load.
This matters particularly for:
Hot-fill products
Chilled food
Cheese and dairy
Fresh produce
Bottled and canned beverages
Frozen products
Hot-fill and condensation
Products such as sauces, preserves, baby food and wet pet food can still be releasing heat after palletisation.
If the pallet is wrapped too tightly in solid film, that heat and moisture can become trapped.
Typical signs include:
Condensation beneath the film
Damp cartons or labels
Pallets remaining warm longer than expected
Long cooling periods before despatch
Condensation is not always caused by the stretch film, but poor airflow can make the problem worse.
Chilled and frozen products
A cold store or freezer can only work effectively if air can move around and through the load.
If the outside of the pallet cools but airflow cannot reach the centre, the product may take longer to reach the required temperature.
The right question is not simply:
Is the cold store cold enough?
It is:
Is the cold air actually reaching the product?
Fresh produce continues to breathe
Fruit, vegetables, salads and other fresh produce continue to respire after packing.
They release heat, moisture and carbon dioxide, making ventilation an important part of storage and transport.
The challenge is maintaining that airflow without compromising pallet stability.
Too little ventilation can restrict cooling.
Too little containment can create an unstable pallet.
The wrapping process needs to balance both.
Where perforated pallet wrap fits
Perforated stretch film is designed for applications where a pallet needs both airflow and load containment.
The openings allow air, heat and moisture to move through the wrapping layer while the stretch film continues to secure the load.
However, perforated film is not automatically better than solid film.
Performance still depends on:
Film specification
Wrap pattern
Machine settings
Pallet profile
Product weight
Required containment
Airflow through the packaging itself
Changing the film will not solve an airflow problem if carton vents are blocked or the pallet is poorly configured.
Airflow and stability should be considered together
The objective should not be maximum ventilation or maximum containment.
It should be the right balance for the product and supply chain.
At Excelerate, we look at the complete pallet wrapping process, including the product, film, wrapping machine, airflow requirement, cooling process and load stability.
Because sometimes the issue is not the cold store or the refrigeration system.
It is how the whole palletised load has been designed to perform after wrapping.
If you are experiencing condensation, long cooling times or difficulty balancing airflow with pallet stability, speak to Excelerate about reviewing the wrapping process.
Time to access your current wrap setup? - https://www.excelerateltd.com/contact-us
Review some relevant case studies - https://www.excelerateltd.com/case-studies
