To reduce the temperature variations of a sensitive product
such as ice cream during long term storage, a low diffusivity
material can be used as a protective panel around the containers.
In this paper, insulation material (polystyrene) and a
PCM (a salt hydrate) have been experimentally tested during
140 days storage. Crystal size was characterised for the two
packagings and a significantly smaller mean crystal size was
identified at the end of the experiment. The main advantage of
using a PCM design is the small thickness necessary to get the
same damping effect compared to the insulation material.
A second test exposed the boxes to ambient air during a
limited time (40 min) and to monitor the temperature rising at
the surface and at the core of the product. PCM thermal protection
in this case provided the best results and could limit
the temperature rising below 1 C. Only a 4 mm thick slab is
necessary to keep the product at the required temperature
during a 40 min temperature abuse.