Millions of tonnes of perishable commodities are on transit around the world every day. Technology is keeping them as fresh as possible to reach the end consumer in total integrity. A look at the brave new world of perishable logistics.
While globalization has made the relative distance between regions of the world much smaller, the physical separation of these same regions is still a very important reality. The greater the physical separation, the more likely freight can be damaged in one of the complex transport operations involved. Some goods can be damaged by shocks while others can be damaged by undue temperature variations. For a range of goods labeled as perishables, particularly food (produces) their quality degrades with time since they maintain chemical reactions which can be mostly mitigated with lower temperatures. It takes time and coordination to efficiently move a shipment and every delay can have negative consequences, notably if this cargo is perishable. To ensure that cargo does not become damaged or compromised throughout this process, businesses in the pharmaceutical, medical and food industries are increasingly relying on the cold chain.
The cold chain involves the transportation of temperature sensitive products along a supply chain through thermal and refrigerated packaging methods and the logistical planning to protect the integrity of these shipments. There are several means in which cold chain products can be transported, including refrigerated trucks and railcars, refrigerated cargo ships as well as by air cargo.
The cold chain is thus a science, a technology and a process. It is a science since it requires the understanding of the chemical and biological processes linked with perishability. It is a technology since it relies on physical means to insure appropriate temperature conditions along the supply chain. It is a process since a series of tasks must be performed to prepare, store, transport and monitor temperature sensitive products.
From an economic development perspective, the cold chain enables many developing countries to take part in the global perishable products market either as producers or as consumers. The growth in income is associated with a higher propensity to consume fruits, vegetables, fish and meat products. Consumers with increasing purchase power have become preoccupied with healthy eating, therefore producers and retailers have responded with an array of exotic fresh fruits originating from around the world.
In all the supply chains it is concerned with, cold chain logistics favor higher levels of integration since maintaining temperature integrity requires a higher level of control of all the processes involved. It may even incite third party logistics providers to acquire elements of the supply chain where time and other performance factors are the most important. As a growing number of countries focus their export economy around food and produce production, the need to keep these products fresh for extended periods of time has gained in importance for commercial and health reasons.
Markus Muecke, global head for airfreight trade lane, management and procurement, for Panalpina, says it is important for every stakeholder to build a multimodal infrastructure for smooth perishable transport from origin to destination. “Sea freight will continue to be the major mode of transport for perishable shippers as this mode offers cheaper and value for money service,” said Muecke. However, he asserted that when it comes to transportation of seasonal products like fruits we need airfreight at the beginning of the season, during the season and at the end of the season.
The success of industries that rely on the cold chain comes down to knowing how to ship a product with temperature control adapted to the shipping circumstances. Cold chain operations have substantially improved in recent decades and the industry is able to answer the requirement of a wide range of products. Different products require the maintenance of different temperature levels to ensure their integrity throughout the transport chain. The industry has responded with the setting of temperature standards that accommodate the majority of products. The most common temperature standards are "banana" (13 °C), "chill" (2 °C), "frozen" (-18 °C) and "deep frozen" (-29 °C), each related to specific product groups. Staying within this temperature range is vital to the integrity of a shipment along the supply chain and for perishables it enables to insure an optimal shelf life. Any divergence can result in irrevocable and expensive damage; a product can simply lose any market value or utility.
The major cold chain technologies in providing a temperature controlled environment during transport involve: Dry ice. Solid carbon dioxide, is about -80°C and is capable of keeping a shipment frozen for an extended period of time. Gel packs. Large shares of pharmaceutical and medicinal shipments are classified as chilled products, which means they must be stored in a temperature range between 2 and 8°C. The common method to provide this temperature is to use gel packs, or packages that contain phase changing substances that can go from solid to liquid and vice versa to control an environment. Eutectic plates. Also known as "cold plates". The principle is similar to gel packs. Instead, plates are filled with a liquid and can be reused many times. Eutectic plates have a wide range of applications, such as maintaining cold temperature for rolling refrigerated units. Liquid nitrogen. An especially cold substance, of about -196°C, used to keep packages frozen over a long period of time. Quilts. Insulated pieces that are placed over or around freight to act as buffer in temperature variations and to maintain the temperature relatively constant. Thus, frozen freight will remain frozen for a longer time period, often long enough not to justify the usage of more expensive refrigeration devices.
Reefer is a generic name for a temperature controlled transport unit, which can be a van, small truck, a semi trailer or a standard ISO container. These units, which are insulated, are specially designed to allow temperature controlled air circulation maintained by an attached and independent refrigeration plant. A reefer is therefore able to keep the cargo temperature cool and even warm. The term reefer increasingly apply to refrigerated forty foot ISO containers with the dominant size being 40 high-cube footers (45R1 being the size and type code). Refrigerated containers, reefers, account for a growing share of the refrigerated cargo being transported around the world.