When it comes to temperature-sensitive shipments, there is no room for error. That’s why we practice an efficient Cold Chain strategy when moving these types of shipments and ensuring successful delivery.
Cold Chain, which refers to all the supply chain steps involved in moving temperature sensitive shipments from first step to last mile, generally involves all the suppliers, products, and logistics involved in making this happen. Compromising steps at any point in the process can result in spoilage, damage, and waste, not to mention harsher implications if health or lives are impacted by a Cold Chain failure.
By examining the factors in success and phase change, you can gain a better understanding of the links in Cold Chain strategy.
Factors for Success
When considering the success of a cold chain strategy it is beneficial to think of two key factors: containment and logistics.
Containment refers to the shipping or transportation container, as well as any thermal refrigerants used in keeping the ambient inside temperature at optimal levels. Common refrigerants include gel packs and blankets, dry ice, and liquid nitrogen for long-term, deep-freeze conditions. Containers come in a variety of shapes, sizes and materials, including corrugated boxes, polystyrene insulated containers or liners, multi material packs with urethane foams, foils, pouches, totes, and even the 100% biodegradable Green Cell Foam®.
Logistics is all about the shipping and transportation of product from origin to destination, and every step in between. Some cold chain strategies include refrigerated trucks or rail cars, while others rely on freight carriers to move parcels expeditiously, including shipping perishables with next day or 2nd day deliveries. Anticipating transit stops and seasonal weather conditions along this path is critical for overall success.
The R Factor Factors for Success
On a technical level, R factor is a measure of thermal resistance. Common building and shipping materials allow varying temperatures on either side of the material to permeate through, and R factor describes the resistance of allowing this permeation to occur. The higher the R factor, the more resistance a material is to heat transfer. For example, because polystyrene has a higher heat transfer resistance than wood it makes a better insulating material. When choosing packaging, focus on increasing the thickness of the insulating material, not the density of the material, for better insulation value.
Phase Change Materials:
Substances are said to change phase when they transform from solid, liquid, or gas to another state. In packaging, phase change materials (PCMs) absorb or release heat when they change phases.
PCMs you might be familiar with? Gel packs, which release heat in a freezing environment and change to a solid state of low temperature. As they thaw inside an insulated container, they are absorbing heat in order to change phases back into a liquid form. The heat absorption pulls that heat from the rest of the container, keeping the contents at a cool temperature. Once they revert back to liquid state and acclimate to the internal temperature of the container, they lose their ability to absorb more heat and become ineffective.
Another PCM used in shipments you might recognize is dry ice, but because it changes from a solid straight into a gas through a process called sublimation, there are shipping hazards to consider. Freight carriers classify dry ice as hazardous— sealed containers can build up enough pressure to fail during sublimation — so certain rules and regulations must be followed when using dry ice as a PCM.
While there are a lot of aspects to take into consideration in a Cold Chain strategy, keep these key concepts in mind. Understanding the fundamentals can lead to successful implementation and transportation of temperature-sensitive products.