An ice pack is a sealed cooling element frozen in advance that absorbs the heat coming in during transport. Its filling takes heat from the surroundings as it melts; when it solidifies again in the freezer it gives that heat back, and the freezer removes it. The difference from ordinary ice is covered in the ice pack and ordinary ice comparison.
Are ice packs and eutectic plates the same thing?
In everyday language ice pack is the name of a broad group: soft gel packs and rigid water packs are both sold under it, and the water-based ones melt at around 0 °C. A eutectic plate is a rigid element whose filling is formulated for a particular melting temperature; it melts at that point below zero and holds its temperature there until it has melted. Every eutectic plate is an ice pack, but not every ice pack counts as a eutectic plate.
GEBHARDT eutectic plates have a food-safe polyethylene shell and a non-toxic brine filling. The melting point is read from the cap colour, so different types do not get mixed up in the store:
| Melting point | Cap colour | Recommended freezing |
|---|---|---|
| -3 °C | Red | -8 °C, 24 hours |
| -14 °C | Yellow | -19 °C, 24 hours |
| -18 °C | Green | -23 °C, 24 hours |
| -21 °C | Blue | -26 °C, 24 hours |
The preparation rule can be read off the table: the freezing temperature must be at least 5 °C below the melting point, and the filling must be frozen solid before use. Depending on the cooling technology this takes 8 to 24 hours, and an air gap is always left between plates so the cold air can circulate. In an Isotec container the plates sit on the upper rails or on an intermediate grid, and the rails take up to six plates.
The right plate follows from the product's transport range. The -3 °C plate, melting just below zero, sits close to the chilled range, while the -18 and -21 °C plates sit close to frozen product; placing a cold-sensitive product next to a -21 °C plate can freeze its surface. The plate's melting temperature and the product's temperature are not the same value either, because the product warms according to its starting temperature, distance from the plate, load layout and the container's insulation. Duration is covered in how long a eutectic plate keeps cold, and selection in how to choose the melting point.
A cost comparison counts preparation as well as the plate price: freezer space, the 24-hour cycle, cleaning, return transport and losses. Send us the route, product and target temperature and we select the plate type and number together; where a temperature profile calculation is needed, we obtain it from GEBHARDT and pass it on.
