The threats to cold chain logistics lie in two areas: the cold store itself and the carriers of the temperature-controlled goods, be they by air, sea or land, and of these the former is where the most problems arise and where the losses from poor temperature control the most horrific, reaching millions of pounds.
Regarding in-transit temperaturecontrolled cargoes, while it is understood that the longer the journey the more careful the temperature has to be controlled, unfortunately the converse is also taken as acceptable, that is the shorter the time the less care is needed. However, the increase in the use of HACCP techniques in transit temperature monitoring using portable recorders and whole chain monitoring by RFID systems, together with ever tighter food safety legislation, will increasingly highlight where real problems lie. It will also ensure that responsibility for product losses results in financial loss to those responsible, which is not always the case.
All refrigerated vehicles should be equipped with on-board electronic temperature monitoring and event logger and must be properly qualified for the designated operating environment so that equipment will not be damaged over unsuitable roads. Passive shipping systems, however, can either dispense with mechanical means of temperature control or make refrigerated vehicles more flexible, as food distributor, Budgens, found when wanting a solution to sending fresh, warm bread at plus 15 deg C within multi-temperature refrigerated trailers which were split chilled/frozen/ambient. It decided to turn the frozen compartments in the trailers to warm ones by reversing the operation of the refrigeration unit and using Olivo portable, insulated containers for the frozen produce.
This also introduced more flexibility in Budgens’ schedules. These passive, portable insulated containers use Olivo’s own manufactured eutectic plates which are cooled down to the correct temperature along with the open-doored containers in a cold store. This pre-cooling helps with temperature control. Such containers may not be cheap, particularly if they are used in air freight and unlikely to be returned. To resolve this the Alternative Pallet company developed its ISPM 15-exempt, 750 kg capacity insulated Pallite pallet box. Its XPS 25mm thick honeycomb board yielded a 12% better insulation performance compared with a corrugated box. When combined with insulating liners and frozen gel packs they make an effective, 100% recyclable, reusable alternative for under £100. They are also stackable and collapsible.
The far bigger source of problems, as already mentioned, lurks within the cold store and as always it is critical to get the design right first time. Apart from the potential horrors around the need to control temperature and air circulation precisely, cold stores can be a money sieve through energy waste, and energy usually accounts for between 20-25% of total running costs. In this respect it is usually worthwhile looking at lighting bills. LEDs would be a good choice because they generate less heat and so less cooling is needed. Their longevity and low maintenance costs are also appreciated.
The key mantra that must never be ignored is that cold chains must always be considered as a whole to obtain best results.