BEHIND THE SEAMS
MADE TO PERFORM
At Expio ALL our styles are FULLY WATERPROOF. We achieve this with innovative farbics and advanced membranes beneath.
What is a membrane? Why do I need one?
A membrane is an additional layer found bonded to the back of the fabric. When a garment is lined, this is completely hidden, yet the membrane is critical to ensure that the item is waterproof. A good one will prevent water from passing through the external layer, but still allow body heat and perspiration to pass back the other way. This enables the wearer’s body to "breathe".
WATERPROOF & BREATHABLE
Interested to know some more techy stuff? Read on…
Membranes are very thin, about 0.01mm, and come in a variety of types. The most common are Microporous and Hydrophilic.
Microporous membranes are defined as a thin-walled structures having an open spongy morphology of precisely controlled pore size typically ranging from 0.03 μm up to 10 μm in diameter. Simply put, lots of tiny holes that allow airflow to pass through them but not water droplets, so you stay dry whilst still allowing perspiration to pass out of the garment.
Hydrophilic membranes by contrast are solid films that lack any visible holes, as a result, they provide complete protection against wind. However, these membranes have the ability to allow moisture in liquid or vapor form to travel through them in only one direction.
This is achieved through molecular diffusion, where moisture moves from areas of higher temperature to areas of lower temperature. Although it may seem contradictory for a membrane without holes to be able to "breathe," it does transfer moisture effectively, creating a microclimate that keeps you dry inside the garment. In our opinion, if the inside of the garment remains dry, then it can be considered as breathing effectively.
eVent® BIO Membrane
Our Optim™ Wool Styles are made especially water and weatherproof by the use of a revolutionary new membrane made using eVent®’s bio-sourced (castor oil) nylon film.
While most membranes are constructed from similar materials, eVent’s process is different. Their product has billions of microscopic pores built in for ventilation, so the fabric doesn’t need to be wet to release water vapour. Gore-Tex, for example, won’t begin to release water vapour until your body produces a certain amount, in contrast to eVent, which begins to breathe immediately. As a result, the fabric can be more breathable in a variety of weather conditions.