Phase-change materials are essential for next-generation cold packs. Do you know the secret behind their efficiency?

Phase-change materials: the eutectic revolution


Temperature-controlled transportation poses constant challenges for all those involved in the supply chain, and technological improvements are always welcome. Phase-change materials offer effective solutions to keep transportation temperatures stable and regular.

In this post, we want to tell you about “smart” materials, how they work and how we use them at Tempack to ensure efficient and safe cold chain logistics.

What are phase-change materials?

From a very broad perspective, a phase change is a transformation that affects the state of any material when its environment’s conditions change and reach a certain point.

Let’s take water as an example. Its “natural” state is liquid (this is the phase it is in), and the temperature can make it change to other states: i.e. a solid state if the temperature drops to below 0oC or gas if it goes above 100oC.

So, why do we talk about “phase-change materials” in cold logistics when referring to very specific materials? Because certain materials change phases in very particular ways, which are especially efficient for fulfilling our purpose of maintaining a constant, regular temperature.

Another example of a phase-change material would be dry ice, which goes from a solid state to gas (without being liquid) in a process called sublimation.

Dry ice, in fact, is commonly used to control the temperature when transporting food. However, this option presents a series of disadvantages as it is difficult to handle, which is why Tempack’s PCM cold packs are the perfect alternative.

Each material with its phase change

The mechanics behind it are simple: a given material (or a mixture of materials) will absorb the heat (or cold) of its environment until it reaches its phase-change point. But not all materials do it in the same way: some have a high heat absorption capacity (called “latent heat”).

Furthermore, if different materials are mixed together, an even more efficient heat absorption capacity can be obtained, offering great thermal stability over a long time. Some of the most popular materials are organic, such as paraffin wax, or inorganic, like hydrated salt.

These mixtures are the basis of eutectic passive cold technology because inadequate combinations make these materials “smart”, allowing their designers to adjust the temperature ranges and maximise the efficiency of the thermal energy transfer between the materials and their surrounding environment.

Tempack’s PCM packs

Our PCM packs are a fine example of eutectic cooling and the use of phase change in our industry. They can be modified to work in given temperature ranges, for example, between +2oC and +8oC or between +15oC and +25oC, making them the perfect solution for thermolabile products, i.e. biomedical samples, temperature-sensitive medicines, gourmet products, etc.

The main difference compared with traditional cold packs is that the temperature range’s high precision means the number of cold packs can be adapted in accordance with the total transportation time, and where necessary, obtain constant temperatures for up to 120 hours, preventing initial temperature excursions.

Another advantage that our customers particularly appreciate is that the PCM packs are filled with chemically inert materials and are made of high-density polyethylene; therefore, they are environmentally friendly, as well as being reusable.

Real cold logistics solutions

Being committed to optimal phase-change materials is being committed to safe, reliable isothermal transport. Do they align with your business model?