Cold, refrigerated or temperature-controlled shipments all involve the same activity: the transport of goods in the cold chain. The growing need to transport temperature-sensitive products safely over long distances saw the birth of cold chain logistics. Today, cold chain logistics is an important part of any successful modern supply chain solution.
Certain products due to their nature or conditions require specific storage conditions. Some foods, for example, are perishable and may deteriorate if they are not kept at a specific temperature. Temperature-controlled transport guarantees this preservation. These products, which include food, medicine and laboratory tests, rely on temperature-controlled logistics to protect their properties throughout the different stages of the supply chain: production, storage, and transport.
What is the difference between normal and cold chain?
The main difference between the cold chain and the normal supply chain is that an almost uninterrupted trace of low temperature (or desired temperature) is maintained during storage and transport of the goods, whereas in normal supply chains this is not the case. For example, in normal supply chains, products can be left in a waiting area or holding area after being picked up from their storage locations before being transferred to transport vehicles.
Transport companies usually provide everything necessary to move the cargo safely. All these processes should be carried out as quickly as possible, and if possible, in dedicated areas. It is also advisable to use shipping labels that show the perishable condition of the goods and indicate to the operator how to handle or preserve them. When choosing a transport company to ship refrigerated cargo, you should ensure that it meets the minimum requirements for preserving your goods.
The keys to effectively managing cold chains are: selecting the right type of containers to package temperature-sensitive products, monitoring temperature and humidity conditions during handling and transport, and avoiding temperature fluctuations.
The cold chain logistics cycle
Temperature-controlled transport refers, therefore, to all processes involved in the order preparation, transport, and delivery of goods under special refrigerated conditions.
Goods must be stored after production until they are shipped to a distribution point or a customer. The storage of certain types of goods must be in temperature-controlled conditions that are protected from temperature fluctuations and power outages. Power outages can lead to quality deterioration or degradation of the goods.
Most temperature-controlled warehouses are backed up by uninterruptible power supply (UPS) systems to deal with these unforeseen hazards. Infrared thermometers are used in cold stores to help record temperature remotely.
When normal thermometers are unable to function due to the extreme cold, hard-wired digital thermometers are used. They are often found in freezer warehouses or in freezer transports.
When transporting temperature-sensitive goods from one point to another, they must be transported in temperature-controlled vehicles that are equipped with refrigeration devices to meet the temperature requirements of the goods. These trucks have a separate compartment or container where the temperature is controlled by portable refrigeration units.
Refrigerated trucks usually have electronic temperature monitoring and recording devices that record and report temperatures and other conditions such as humidity, etc. inside the vehicle, from the time the devices are switched on after the goods are loaded until the goods are unloaded. Some have alarm systems that can send alarms to the operator under certain conditions, or are activated when the vehicle door is opened or when the temperature is below or above a set threshold.
Another method of maintaining low temperatures inside a transport vehicle with a separate storage compartment is the use of dry ice or frozen gel packs. Dry ice is solid carbon dioxide used as a cooling agent, and frozen gel packs use water, a thickening agent and silica gel. This method is often used for short distance transport of products that need to be stored in cold environments.
Temperature-controlled goods also require special packaging in order to protect them during transport. The main types of packaging for cold storage are:
- Cardboard: An affordable, customisable, and durable material, which is widely used in the e-commerce industry. However, there are better options for securing the cold chain.
- Aluminised Foam: This is an insulating material that is used to coat the package to provide a second layer of protection.
- Polyurethane: Plastic material with high insulating capacities. It can be used both to shape the packaging and to give it an extra layer of insulation.
- Cold engines: These are cold accumulation devices that are inserted into the packaging to maintain the cold chain in any condition. You can find them in solid or gel form.
- Reefer containers: Popularly known as reefer containers, they are often used as tertiary or secondary packaging for cold shipments. Basically, they are like a small portable cold room that protects the product during transport and distribution.
- Special tanks (dry shippers): They are used only for the transport of goods with extreme cooling mechanisms, such as dry ice or liquid nitrogen.
Different products have different temperature requirements. The term “cold chain logistics” can sometimes be confusing. Depending on the type of product, the temperature requirements for storage and transport vary. Not all products need to be kept at very low or sub-zero temperatures. Some may need to be stored and transported at room temperature to preserve their texture and quality, which can be challenging in certain climates.
The growth of global trade in recent decades has seen several innovations and evolutions in the way business is done, as well as in the equipment and infrastructure used for storage and transport of products, and temperature-controlled transportation is no exception. The evolution of cold chain logistics is a direct result of the growth of global trade and supply chains.