Phase change material coated fabric
PCM Fabric is can passively absorb and release heat. Working like a battery if given energy (exposed to warm temperatures) it draws that in, holding that energy until it is needed (exposed to cooler temperatures). It works well in work out gear helping maintain the right body heat in different environments.
When I show PCM fabric to people they are always surprised, it’s the ability to consume heat often makes it feel like the material has come out of a fridge, when in fact it’s actually drawing in heat from the surface of your skin. Its benefit comes from the ability to store this heat and release it later, though it is important to note there are limits to how much heat can be stored and how quickly it is released. It is important to remember that the PCM is a coating to a fabric. The amount and distribution of these particles limit the effectiveness of the material. The rub is that the more particles you add the rougher and less pleasant to the touch the material becomes, an extremely high amount has an amazing effect but you certainly wouldn’t want clothes made from it. Companies, like outlast shown on this page, have found ways to build more of these PCM particles into their clothing without sacrificing the texture but limits remain.
The fabric is still underutilised in my opinion, with some of the most popular uses being bed sheets and underpants. I think there is huge scope to expand how this material is used, both in medical and commercial situations. Though I am pleased to see it starting to be used in battery tech.
Outlast is one of the companies offering this technology, their offering is solid and they are pretty accurate in their marketing.
|Material category||Smart Material|
|Manufacturing properties||Treat as textile|
|Sustainability||No specific process|
|Key limitation||Heat retention is limited by the amount coated, the more coating the rougher the fabric|
|Maker||Outlast, Scoeller and others|
The principle at work is the same as we see in those hand warmers where you click a disc and it then releases heat as it changes from a liquid to a solid. You can then reuse them by boiling them. (Don’t know what I’m talking about, there is a good summary of the effect on this site, which also provided the picture)
Phase change material fabric wouldn’t be anything without the Phase change material powder coating it. The powder itself is available separately.
The example I often use is it’s great for joggers who may run, building up the heat reserve and then encounter rain that cools them, then the PCM fabric releases it’s energy back into them helping them stay at the right temperature.
I’ve added a great video of a biker explaining how it helps keep him at the right temperature while he is out on the bike. It’s really helpful to understand the process as well as the importance of the application.
My favourite suggested application is to help keep babies, whose bodies are small and prone to rapid change in temperature, at the right body temp when they have a fever.