Science shows the functionality of a sheep fleece
Man-made fibers can’t get close.
Herdwick are hardy from birth and native to the rugged fell mountains of the Lake District. It rains in the here, almost all the time.
Whilst the Lake District might conjure up images of Windermere bound coaches stuffed with wheeled luggage, and passengers barely pre-coma on Kendal mint cake, it is also the wettest place in the UK.
The weather is extremely variable, with several heavy showers possible each day, even on sunny days. It’s mountain weather in the North West of England. Atlantic winds hit Britain at this height – but having passed over Ireland and the lowlands first, they are hectic and very changeable.
It is obvious that the sheep’s fleece is getting wet when it rains. With a moment’s thought it is equally obvious that the sheep itself isn’t. A wet sheep in these parts would be a dead sheep very quickly. Even on a sunny day hill walkers are advised by the government to check the weather. Locals will tell you to expect rain today, every day.
The capacity to absorb up to 30% of its own weight in water sounds like a sales pitch from Vileda. But the way sheepskin handles moisture couldn’t differ further from what is happening in the mop. In the mop we see the capillary action in full effect, holding onto water after a drenching. The mop is saturated. The sheepskin of course gets better treatment, and in return you get to feel like your bed was prepared for a Disney princess. So, what is this sheepskin actually doing with the moisture then?
Herdwick Sheep | Heritage Breed
Staying dry is easy: all you have to do is not tolerate water.
Sheepskin has several advantages we make use of, and one spectacular feature that we don’t. Firstly, each individual wool fiber is hydrophobic. Wool fibers repel water and dry easily. Secondly, the physical structure of the fibers traps the air (and in the UK this mean moist air). Thirdly, the moisture in the air causes friction as it condenses on the (happily reluctant) wool fibers. The water has to give up its own sweet vibration before it can condense, and as we all know it takes a lot of energy to change matter from a liquid to a gas. The sheepskin resists the water condensing upon it, until the energy the water gives up is sufficient. It is this energy that the sheepskin harvests for free. It is this friction that makes sheepskins get warm and stay dry – incidentally, a sheepskin has to be really quite wet before it feels too damp. It’s these specific physical properties that set sheepskin way above all man made fibers on the utility score chart, but don’t discount the fact it looks lush and feels good on the skin to. Oh, the sheepskin quality we leave at the farm gate? Lanoline. Sheep naturally have very oily fleece, which we reduce dramatically during the tanning process. If your princess happens to have sensitive skin just wash the sheepskin first like a pair of jeans with your normal washing powder.