Introduction into GORE-TEX

Gore-tex over many years has come to be the industry leader in modern waterproof fabrics, its light-weight and breathable property's put Gore-tex at the top of the market.  Gore-tex was created in 1969 by Bob Gore. He created a material called Polytetrafluoroethylene (other wise known as PTFE). The material was then stretched to form ePTFE (an expanded version of Polytetrafluoroethylene).

ePTFE membrane at the microscopic level

Note that GORE is the company name, so if the label says "GORE..." don't immediately assume its Gore-tex as Gore makes many different types of fabric that are not waterproof such as GORE WINDSTOPPER which is a totally windproof fabric membrane.


The beauty of Gore-tex is that it the microscopic structure of the material has properties that allow air out but not water in.Gore-tex fabrics have pores (tiny gaps in the fabric) that are around 20,000 times smaller than a droplet of water however these pores are 700 times bigger than a molecule of water vapour (sweat) which allows the fabric to allow perpreation out (giving the fabric its breathable property's). In a square inch of Gore-tex there are approximatly 9000,000 pores which allow water vapour to vent out. And because these pores are so damn small wind cant pass though making Gore-tex totally windproof.

Gore-tex layering structure 

Gore-tex fabric is made in a process called lamination, this is were all the different layers of the fabric are adhered together to make one material- the final material that your gore-tex product will be made out of. The layers of a Gore-tex fabric may vary because there are different versions of Gore-tex about, but typically Gore-tex consists of 3 layers.

Layer 1: This is the outer most layer, it consists of a outer fabric (known technically as "face fabric") and is the most rugged part of the material. This layer of material is designed to cope with the stresses of uses and is treated with a DWR (durable water repellent) to make that outer fabric hydrophobic. Hydrophobic fabrics have the a very unique property that when water comes into contact with it the fabric it doesn't adsorb it-but rather the water beads up on the surface as seen below.    

Layer 2: The inner layer (this is where the Gore-tex membrane is found). this is what allows a Gore-tex jacket to breath and remain totally waterproof. You wont see this membrane unless you tear the outer or inner fabric (which I don't suggest you do) because it is sandwiched or "laminated" between the outer and inner fabrics. Because neither the outer or inner fabrics are technically waterproof the Gore-tex membrane can become contaminated with sweat or dirt, that's why after extensive use you should wash your Gore-tex gear but we'll talk about that later.

Layer 3: The inner most layer. This layer is what you see on the inside of the Gore-tex fabric. Its  usually a softer fabric for next to skin comfort, but some more hard wearing products just have a layer to protect from sweat contamination. 

Gore-tex products carry the famous "guaranteed to keep you dry" promise on all types of Gore-tex products. This guarantee covers the all three aspects of the fabrics quality's ,weather it be windproofness, waterproofness or breathablity.

Gore-tex however isn't just one type of fabric, There are multiple types of Gore-tex fabric but im going to cover the main 4.

Gore-tex Pro Shell-   Designed for use in extreme weathers for activity's like mountaineering.
Pro Shell uses a 3 layer construction making it the most durable of all the gore tex fabrics.

Gore-tex active shell- Designed for single day activity's that are highly aerobic. The active shell fabric is designed with breathability in mind and is the most breathable variant of goretex.

Gore-tex shell- The standard Gore-tex shell for use over multiple outdoor activity's.
2 layer construction uses the outer and membrane fabrics which are bonded together and uses a lose mesh inner material.    

Gore-tex Paclite- Light weight and packable waterproof for casual use.
Paclite uses a carbon "half layer" to complete the fabric construction.