The term “Cold Chain” refers to a temperature-controlled supply chain. A cold chain is an uninterrupted series of storage and distribution structures and activities which maintain a given temperature range for the product. This controlled temperature can be very cold (cryogenic), frozen (typically -5 to -30˚C), “tissue” (2 to 8˚C), or some other value. The Cold Chain is used for extending and ensuring the shelf life of a wide variety of products ranging from fresh produce and flowers to DNA tissue samples.
As a certified test lab, Westpak uses environmental chambers to simulate temperature profiles that a package may encounter in distribution. A Cold Chain package normally consists of a thermal barrier or insulation medium protected by a “distribution” package exterior with thermal masses (wet ice, dry ice, gel packs, or similar) on the interior. Most Cold Chain packages are “passive” in that they rely on the “preconditioning” of the product and/or the thermal mass to maintain temperature. “Active” Cold Chain packages can also be employed if the product and/or the distribution environment demand it. Active Cold Chain packages require a power source and are not commonly used.
During the performance testing for Cold Chain package systems, thermocouple probes and separate temperature dataloggers measure temperatures within the product to determine the response to the test condition which is designed to mimic the intended distribution environment. Test results can be used to defend the package configuration when audited by regulators. It should be emphasized that both the thermal performance of the Cold Chain package as well as its mechanical integrity is important for a successful distribution. Therefore it is important not only to determine how long the package will maintain the required temperature, but also its ability to withstand the normal impacts, vibration, and other mechanical excitation common in product distribution. Westpak has extensive experience in lots of equipment for a variety of different Cold Chain related testing services.