A British team of scientists at TLX Cargo Ltd. invented a cargo cover/thermal blanket that incorporates phase-change material (PCM) into its structure in order to resolve the problem of hot lane temperature excursions on the tarmac.
TLX PCM is designed to remove the problem of the temperature spikes seen on most pallet data loggers in air cargo when the pallet is off-loaded on to the tarmac at hot locations. It’s described as a game-changer in the temperature-controlled logistics sector, solving problems such as: excursions on 15°-25° C routes, power outages on 2°-8 o C routes, upgrading and reducing the size of parcel shippers, along with controlling temperatures of ULD’s for perishables.
TLX PCM cargo covers combine an outer surface that reflects 97% of thermal radiation over the measured spectral range with TLX PCM Fibre-Flex technology within the structure of the cover, remaining flexible even when frozen. It can be molded around corners, while being thin, light and easy to handle.
In its liquid state the PCM fiber will hold the PCM in any orientation, which means TLX Fibre-Flex can be used for walls as well as the top of cargo covers. According to the company, traditional PCM’s are expensive and difficult to use. They crystallize into a frozen block but even in a liquid state they must be contained in rigid containers or gel packs. PCM packs have the potential to burst if pressure is applied; corners and joins in rigid packaging create gaps that are thermal weak points. Traditional PCM’s are also heavy and can be difficult to apply in thin layers.
The TLX Cargo 15°-25 o C blankets freeze at around 18o C (i.e. in the aircraft hold) and then, once out in the sun on the tarmac, they inhibit the heat build-up within the pallet load by absorbing the heat from the sun. With this system, the freezing and melting process can be repeated continuously through the journey as the pallet is loaded and off-loaded on to the tarmac.
Phase-change materials are able to absorb energy as they change from a solid to a liquid, so they can act as heat buffers. How long they absorb heat for is dependent on the ambient temperature.