1. WHAT IS A PERMEABLE MEMBRANE?
A membrane is a technologically advanced, specially designed material used in many branches of the economy, particularly in the leather and textile industry. We wear clothes which contain membranes, we walk in shoes with a membrane as well as live in houses in which, in the process of construction this versatile material is also used.
2. WHAT DO WE ACTUALLY NEED THAT MEMBRANE IN OUR SHOES FOR?
Shoes are the last element we put on our foot to protect it from unfavorable weather conditions. And what threats are we exposed to? Wind, rain, snow, on the one hand. On the other, sun and high temperatures. Such protection would not be possible to such a high extent if it was not for the membrane.
3. WHAT DOES A MEMBRANE LOOK LIKE?
By saying “membrane” we simplify the entire concept to a big extent. Both in clothes and in footwear membrane is used in the form of a “laminate”. What is a laminate? It is nothing but combination (laminate) of membrane with another material which has an effect on the operation of the membrane as well as its functionality.
4. WHAT PROPERTIES DO MEMBRANES HAVE AND WHAT DO THEY PROTECT US FROM?
First of all, a membrane protects us from soaking our shoes. Thanks to its application shoes become waterproof and we can successfully use them when it rains or snows.A membrane protects us not only from what is outside, but also our own moisture (sweat) - and this is what we call breathability, i.e. transmission of vapor out of the material. Thanks to these properties our foot stays dry.
5. WHAT TYPES OF MEMBRANES ARE AVAILABLE ON THE MARKET?
Membranes can be divided into two categories.
The first division according to the type of material used for their production:
- Teflon (PTFE) membranes – e.g. GORE-TEX membrane,
- polyester (PES) membranes – e.g. SYMPATEX membrane,
- polyurethane (PU) membranes – the most modern membranes – OUTDRY membrane.
The second division according to the method of installation in the product (shoe):
- sock membranes - GORE-TEX or SYMPATEX,
- directly laminated membranes - the most modern and most effective technology - OUTDRY membrane.
6. WHAT DOES IT MEAN THAT A MEMBRANE IS A SOCK OR DIRECTLY LAMINATED MEMBRANE?
The name sock membrane was inspired by the fact that a sock-shaped element is sewn from the membrane, which is then inserted into a shoe and sewn in.
A directly laminated membrane is mounted in a shoe with the use of a special 3D machine. Due to its exposure to air and high temperature the membrane is “thermally ironed” into the inner part of the shoe. In order to better understand this technological process, let us imagine that we are turning the boot top inside out and a machine resembling a very modern iron presses the membrane into the shoe.
7. WHICH MEMBRANE IS BETTER AND WHY? WHAT ARE THE DIFFERENCES?
Thanks to its modern features and innovation, the OUTDRY membrane is superior to traditional sock membranes in every respect. Here are a few of the most important advantages:
Due to the innovative membrane placement technologies, the OUTDRY membrane has significantly better waterproof properties than Goretex membranes. Thanks to the 3D lamination machine, the entire process of mounting the membrane into a shoe lasts merely a few seconds. In this technology no sewing machines are used, there are no seams through which water could permeate. Therefore, such shoes are completely waterproof.
In this parameter, the OUTDRY membrane also has a big competitive advantage thanks to the use of membrane technology. In order to use a sock membrane, e.g. Goretex, inside a shoe a membrane “sock” must be sewn first - an d this already involves elements which has to be sewn together - in this way seams are made, which must be protected - i.e. an adhesive must be used and to put it simply, glue the parts. Next, such a membrane sock must be sewn inside the shoe and here, again we need sewing and gluing. All of those procedures in the form of sewing and gluing reduce vapor permeability, to a large extent. There has been no adhesive invented so far that would be air permeable. The OUTDRY membrane is a seamless and non-adhesive technology, thanks to which a shoe can “breathe” with all its surface and not just the glued parts.
The light weight of the boot will be most appreciated by those who ever had to walk for many hours in heavy, water soaked shoes on a difficult terrain. As studies show, shoes can double their weight because of soaking. Not everybody knows, however, that there are no waterproof leathers available on the market, only those with limited waterproofness. Their application in shoes, even the best ones, does not guarantee that after a few hours of walking in moist terrain, such boots will stay dry. The guarantee of waterproofness is the very membrane. A question may be asked, what does a membrane have to do with leather getting soaked with water and weight. The answer is simple - not a membrane as such is crucial here, but the method of its installation inside a boot.
And here again, OUTDRY proves superior to traditional sock membranes. As we wrote before, a sock membrane of Goretex type is nothing but a shoe with a membrane sock sewn inside it. It looks as follows - we have an outer shoe leather - under the leather, inside the shoe there is everything that is usually there, and namely, footwear sponge fillings, a fabric or leather lining and on top of that, an additionally sewn in membrane sock. The impact of water exposure has the following consequences. After some time even the best waterproof leather gets soaked and lets water through into a shoe. All lining materials get gradually soaked with water. It goes without saying that a sponge, even the one used in footwear production, likes water. Water fills the inside of a shoe and gets to the membrane sock. It is usually here, if of course a membrane sock is well made and protected, that the water journey inside a shoe ends. A foot stays dry, but there is plenty of water inside the shoe, which must additionally be carried. Besides that, drying of such soaked boot is not that easy, either.
Things are different with the OUTDRY membrane. In this technology, however, we have an external waterproof shoe leather. On its inner part there is a seamless membrane which thermally pressed in, followed by all the rest, i.e. the above-mentioned inside materials, footwear sponges and lining fabrics. When used on a wet terrain - water - which after some time “wins over” the waterproof leather encounters an unsurmountable obstacle - the OUTDRY membrane. Thanks to that all fabrics used inside the shoe as well as the foot stay dry, while the shoe only slightly and unnoticeably increases its weight.
8. HOW TO CLEAN SHOES WITH THE OUTDRY MEMBRANE?
The membrane is a material located inside a shoe and it does not have a direct contact with footwear cleaning and maintenance agents. It is very important, however, to select the right cleaning agent that will match a specific type of leather our shoes are made of. Agents used in the case of grain leather (plain) differ from those used for velour leather (commonly called “suede”). It is very important, since the use of unsuitable agents makes leather lose its properties (e.g. if we polish leather with a thick layer of shoe polish, it will lose its breathability, and as a consequence, also deteriorate membrane properties, as in this way we will reduce vapor permeability). Footwear cleaning and maintenance agents should be bought in shoe stores, where the range of such products is wide and we can rely on professional advice.
9. I HAVE SHOES WITH THE OUTDRY MEMBRANE BUT THEY GET SOAKED ANYWAY. WHY?
The question if we use such footwear properly is very crucial. In majority of such cases water permeates into a shoe “from the top” and we think that our shoes actually let water in. There are numerous examples to prove this theory. The most common one is putting trouser legs with water dripping down on them into our shoes. It often happens that we walk in shoes on high, rain- or dew-wet grass. In such conditions trousers get soaked very quickly and “transport” water into a shoe. Let us remember that by setting off to a difficult, wet terrain we must be equipped not only with proper shoes, but also the right clothing, which protects us from water.
10. HOW TO CHECK IF SHOES WITH THE OUTDRY MEMBRANE ACTUALLY FULFILL THEIR DECLARED PROPERTIES?
There are many types of tests and inspections. Starting from those performed in accredited laboratories (i.e. such in which results are unquestionable and recognized basically around the world) to regular field tests performed by appropriate persons who deal with a given profession (e.g. forest officers) or those using footwear because of a given hobby (angling, hunting, trekking, etc.). For us - a footwear manufacturer - customer feedback is very important - thanks to your reviews and suggestions we can constantly improve our shoes.
As a manufacturer of footwear with the OutDry membrane, we make sure that our shoes are always of top quality. We therefore have our own company laboratory, in which we test and check every batch of shoes ourselves. The shoe testing machines we have are equivalent to those used in accredited laboratories. Two of them are particularly worth mentioning:
- WALK TESTERA footwear test performed with the use of this device consists in simulation of walk in water. A shoe is put on a special last (a type of an artificial foot/leg), which is equipped with a number of electronic sensors which record increase of moisture or water leaks. We pour water and start the machine. The test imitates a walk over a distance of 100 km in wet conditions. After a test, a shoe is weighed - and if it increased its weight by more than 10% and the sensors did not record soaking, the shoe is considered as having the right quality.
- CENTRIFUGEA centrifuge resembles a large centrifugal separator. You put shoes to metal “boxes”, pour water in them and place the “boxes in a machine”. After activating the centrifuge, the boxes begin to rotate at 250 rpm. In this way water pressure of 30 Kpa is generated. It is with such a power that water makes an impact on shoes, testing their leak-tightness. The pressure can be compared to a rapid torrent of a mountain stream.