Improving Thermal Performance? + Roll Cage Fill

3. What Can be Done to Improve Thermal Performance?

Certain attributes can be improved whereas others cannot. For example, product weight and specific heat capacity are inherent and unchangeable attributes. However the starting temperature of the product can be changed.

The following changes will improve temperature retention:

3.1 Core Temperature Prior to Distribution

3.1.1 Keeping product temperature down prior to distribution means core as well as surface temperature. Blast freezing or leaving products near a freezer air outlet will only provide superficial benefit. Core temperatures will only be affected if a product is left in the optimum temperature for a long period of time (depending on the size of the product).

3.1.2 Thus, the buying function may need to factor in the time and cost arising from the need for adequate product refrigeration at either the supplier or retail warehouse.

3.2 Improved Thermal Cover/Liner

3.2.1 The thermal cover/liner can be improved through enhanced filling (new products are coming to market almost continuously). The great problem is that reduced thermal conductivity requires thicker filling.

However, there are limitations on the thickness/bulk that can be achieved:

3.2.1.1 Handling: they are harder to fold and stow

3.2.1.2 Weight: they are heavier and thus are slower to put on and take off and may occasionally require extra labour (2 people instead of 1) etc. They will also cost more in diesel

3.2.1.3 Vehicle and storage cubing: if they are too thick they may not fit side-by-side on a vehicle or in storage, thus using extra vehicles or extra storage

3.2.1.4 Thicker covers/liners will rub against each other and rub against other objects more forcefully, potentially limiting their life (and the life of other objects)

3.2.1.5 In production they can only be a certain thickness before the stitching operation that seals them in becomes unworkable

3.2.2 However new products are increasingly achieving improved insulation with less bulk/weight by using improved foundation materials or through weaving or layering. Thus each new generation of covers or liners achieves improved performance for the same bulk of filling.

3.2.3 The thermal covers or liners can also be covered with thicker skin (both internal and external). This will improve thermal performance while improving durability.

3.2.4 Changing to a shiny colour (silver ideally).

3.2.5 Inclusion of eutectic plates (either loose or in pouches).

 

4. Roll Cage Fill

4.1 Air is a good conductor of heat and therefore undermines thermal protection.

4.2 Retailers will already have systems in place to minimise the amount of partially full roll cages being employed. However this factor adds to the importance of this issue and thus, a greater emphasis on this issue may be appropriate

4.3 Partially full roll cages can be bulked out with other objects e.g. other thermal covers or liners can be bundled in the cage or even empty boxes can be used.