– an original hydrophobic Teflon membrane with a porous structure and integrated oleophobic protection, developed by BHA Technologies. Its features are excellent breathability, high moisture resistance, evaporation is removed directly through a pore-free membrane without diffusion. This membrane works better than others at sub-zero temperatures and high external humidity, and also reduces the likelihood of overheating. As a result, eVent materials allow human body always stay in your comfort zone. Unlike other membranes, eVent uses Dry System and Direct Venting technologies. Therefore, there is no need to protect the membrane from body secretions with an additional polyurethane coating. All fibers of the material are treated with such a substance for oil based, which creates a structure of constantly open pores. This increases the conductivity of body evaporation.

The most important advantage of eVent membranes is that they remove moisture equally well at both high and low humidity levels. Independent laboratory tests from the renowned Swiss institute EMPA have confirmed that the eVent membrane is currently the most breathable of all similar materials on the market.
There is another unique feature of the eVent membrane. Its fibers are treated with a substance of such a composition that allows the product to be washed repeatedly using ordinary detergents. And this does not reduce the breathability and waterproof properties of the membrane. Moreover, to maintain excellent vapor permeability, BHA Technologies engineers recommend washing products made from eVent membrane fabrics more often.
eVent Pro 3L is a new exclusive material that takes into account the most progressive trends in the development of membrane materials. It surpasses the classic eVent in many respects: breathability, moisture resistance, softness and durability of the inner layer. This material high level Provides comfort during active movement and prolonged precipitation. The body not only does not get wet, but also does not overheat, maintaining a normal temperature.

On this moment There are many products on the market with the eVent membrane, which differ significantly in functionality and cost. This is due to the fact that the owner of the rights to the eVent brand and the manufacturer of the membrane, GE, has allowed manufacturers to use their own names for fabrics with the eVent membrane since 2011. True, most of these membrane materials are still inferior in properties to the classic eVent produced by Mitsui.

What are membrane fabrics used for?

The main goal is to produce waterproof and, at the same time, vapor-permeable clothing?
Why are rubberized fabrics or materials such as PVC films not suitable, because they truly provide one hundred percent moisture protection?

For the purpose of thermoregulation (a person’s ability to maintain body temperature, primarily the brain and other internal organs, within narrow certain limits, despite significant fluctuations in the temperature of the external environment and its own heat production), moisture evaporates from the surface of the skin through the pores. With increased physical activity, heat production increases and, accordingly, sweating and heat transfer. If clothing does not cope with the removal of fumes, the person overheats and, as a result, gets wet through in his own sweat. Therefore, clothes through which fumes cannot pass are uncomfortable. The use of vapor-permeable membranes in fabrics helps to minimize this disadvantage. The membrane is not able to completely eliminate it, since in terms of vapor permeability it occupies an intermediate position between simple fabrics and completely impervious to moisture materials, that is, figuratively speaking, membrane fabric breathes better than polyethylene, but worse than tarpaulin. This way we get fairly high moisture protection at the expense of vapor permeability (breathability).

The downside of membrane fabrics is that, due to the ability to transmit steam, absolute moisture protection is not provided, that is, under certain conditions the membrane can get wet (leak). In this regard, two main indicators of membranes are considered, namely vapor permeability (the ability to allow water vapor to pass through) and water resistance (the ability to keep water out).

In general, everything is clear with water resistance; this is the height of the water column in millimeters, the pressure of which the membrane fabric can withstand without getting wet. The higher the water resistance of the membrane, the more intense precipitation in the form of rain it can withstand without leaking.

With vapor permeability the situation is somewhat more complicated. The most common indicator is vapor permeability MVTR - Moisture Vapour Transfer Rate (the amount of water vapor that the membrane can transmit), usually indicated in grams per square meter per 24 hours (g/m2/24h). The higher this value, the more comfortable the clothing, but this indicator does not quite adequately reflect the behavior of the membrane in real conditions, since measurements are carried out under some ideal conditions.

It is believed that another indicator more adequately reflects the level of comfort - the resistance of the membrane to vapor penetration RET - Resistance Evaporative Thermique. The lower this figure, the better.
For the production of membranes, polyurethane PU and polytetrafluoroethylene PTFE are most often used.

There are two fundamentally different types membranes - microporous and non-porous (hydrophilic).

The hydrophilic membrane is a monolithic thin PU film, the molecules of which enter into chemical bonds with water molecules, ensuring their transport through the thickness of the film. Such membranes have an undeniable advantage, which is expressed in the fact that they are not critical to contamination, but they are not without significant drawbacks. First, the membrane must first get wet in order to begin to remove moisture. The second is that the process of transporting molecules is quite slow. Third, chemical bonds are not unidirectional; accordingly, the transport of water molecules can occur in both directions. In the case when the absolute humidity outside the membrane is higher than inside, the partial pressure gradient will be directed inward and the movement of water molecules, accordingly, will also occur inward.

The structure of the microporous membrane is similar to a multilayer web, the size of the holes and the high water-repellent properties of PTFE polytetrafluoroethylene allow the membrane to withstand fairly high water pressure without letting it pass through the structure. At the same time, water vapor molecules freely penetrate through the pores of the membrane. Such a membrane was created about 30 years ago by W. L. Gore, but it soon became clear that body fat, detergents and dirt, accumulating in the structure of the membrane (settling on the fibers) greatly reduced its water-repellent and breathable properties.

To protect the PTFE membrane from contamination, Gore engineers decided to cover it with another membrane - a hydrophilic one. The structure of the PTFE membrane is such that it allows laminating a very thin PU membrane, several times thinner than the same membrane applied directly to the fabric (as is done in conventional hydrophilic membrane tissues), and the thickness here is of fundamental importance, because, as noted above, the process of transporting molecules is quite slow and its speed directly depends on the thickness of the membrane layer. As a result, the breathability of the Gore-Tex membrane deteriorated noticeably, but was still much better than most other membranes before the invention of eVent ® . eVent ® is an advanced expanded polytetrafluoroethylene (PTFE) membrane that forms a waterproof barrier while maintaining high vapor permeability properties.

This material was created by BHA Technologies, USA. The main difference between eVent ® and other membranes is that eVent ® uses Direct Venting and Dry System technologies, which eliminates the need to apply an additional polyurethane coating to protect the membrane from body secretions. All fibers are treated with a special substance (oil-based), which allows you to create a structure of constantly open pores, to increase direct conductivity and evaporation of body secretions, instead of initially falling on the protective polyurethane layer.

eVent ® direct ventilation technology (eVent Direct Venting™ technology) works at any temperature and relative humidity inside. Simply releases fumes directly and immediately.

Laboratory testing results for eVent ® fabrics:
breathability RET - 3–5 method for measuring fabric resistance to evaporation ISO 11092:1993 vapor resistance coefficient; breathability MVTR - 15000–25000 g/m2/24h, inverted bowl method JIS L 1099 B2 moisture evaporation coefficient.
Comparative breathability tests between Gore-Tex and eVent ® membranes were conducted at the University of Kansas, results in the chart:

Dynamic Moisture Penetration: Tested at Kansas State University (ASTM F2298). XCR ® is a registered trademark of W. L. Gore & Assoc.

The breathability of the eVent ® membrane exceeds that of Gore-Tex membranes by 30–200%, depending on the degree of humidity. The most important advantage is that eVent ® removes moisture equally well, both at low and high levels of humidity. At 70% humidity, eVent® breathes 30% better than Gore-Tex XCR, and at 30% humidity it breathes 200% better.

The well-known Swiss institute “EMPA” conducted independent laboratory tests and officially stated that today the eVent membrane is the most “breathable” of all those on the market.
To the above mentioned features of the eVent ® membrane, one more should be added - the composition of the substance with which the fibers are processed allows the products to be washed multiple times using conventional detergents without reducing the waterproof and breathable properties of the membrane. Moreover, BHA Technologies engineers recommend washing eVent ® membrane fabrics more frequently to maintain high vapor permeability.

In Russia, at the moment, VNA Technologies has issued a license for the production of clothing from eVent ® membrane fabrics only to the Five Stars company, which produces clothing for active recreation, tourism and extreme sports under the Sivera trademark, with the right to sew at its own production facilities.

Konstantin Tikhonov. year 2009

EVent is the world's only hydrophobic polytetrafluoroethylene (PTFE) pore membrane with integrated oleophobic protection. Manufactured by BHA Technologies since 1999. The eVent membrane has been successfully used in activewear and outdoor activities as one of the most highly breathable membrane options on the market.

Today eVent is a whole series of waterproof fabrics with moisture resistance ratings ranging from 10,000-30,000 mm water column.

In the world of outdoor clothing, footwear and equipment, the traditionally trusted name is microporous membranes, that is, membranes consisting of a hydrophobic material (usually polytetrafluoroethylene). Such membranes have many microscopic holes, the size of which does not allow water droplets to penetrate inside, but is large enough to allow individual molecules of water vapor to pass through during evaporation. It is believed that such membranes provide the highest level of protection from external influences and durability of the product; Gore-Tex is the undisputed leader here. The main problem with microporous membranes based on pure polytetrafluoroethylene is contamination of the pores with dirt, body fat, etc. As a result, performance qualities are reduced, and above all, breathability and water-repellent properties suffer.

Combining microporous and non-porous (hydrophilic) membranes into a kind of layer cake somewhat solves this problem, but the breathing characteristics still deteriorate. The famous company Gore-Tex followed the path of creating a sandwich structure and, indeed, throughout the 2000s, its products were the best in terms of all their performance qualities.

The main advantage of the eVent membrane is its unsurpassed breathability with the required high level of moisture protection. In the production of the eVent membrane we use Direct Venting technology, direct ventilation. Thanks to this, there is no need to protect the membrane from secretions from the surface of the skin (oils, salts, etc.) with the help of an additional polyurethane coating of the fibers, unlike combined membranes, such as modern versions of Gore-Tex.

Thanks to the oleophobic treatment of the fibers that make up the membrane, the pores of the membrane remain open constantly. eVent membranes are the only ones in the world at the moment that have not only hydrophobic, but also oleophobic qualities. Moreover, their performance characteristics (water resistance and vapor conductivity) are among the best on the market. It is worth noting that the evaporation of excess moisture occurs directly through the membrane, without diffusion. That is, contact of wet materials with the surface is not necessary. Actually, the technological details of imparting protective oleophobic properties to the PTFE base are kept secret by the manufacturer.

eVent membranes also have a number of advantages over non-porous polyurethane membranes: to remove moisture, the eVent membrane does not require increased humidity on the inner surface of the fabric, which often leads to discomfort.

During intense exercise in nature, you are constantly balancing between overheating the body if excess moisture is ineffectively removed to the outside, and freezing, which follows as soon as the load and, therefore, the release of heat stops. Therefore, it is very important to remain in the comfort zone, which only the most vapor-permeable membranes can provide.

It should be noted that the weaknesses of eVent membrane materials are often cited as possible lower wear resistance and durability. Unlike Gore-Tex, which has been actively tested for four decades, in the case of eVent this has yet to be confirmed or denied

According to the breathability tests (RET and MVTR), the eVent membrane outperforms most known membranes on the market. Thus, according to the results of individual tests, the vapor permeability of the eVent membrane, consisting of PTFE film with oleophobically treated fibers, is practically no different from the vapor permeability of pure PTFE film, which, of course, can be considered an excellent result. It is also important that the eVent membrane effectively removes moisture, even at subzero temperatures and low humidity.

Vapor permeability RET (evaporation resistance coefficient): 3–5 , method for measuring fabric resistance to evaporation ISO 11092:1993 Vapor permeability MVTR (water vapor transport rate) - 10,000–30,000 g/m²/24 hours, inverted bowl method JIS L 1099 B2

Thanks to the use of Direct Venting technology, the membrane is not afraid of repeated washing. Moreover, the manufacturer recommends washing products as often as possible to maintain high moisture removal rates. Recommendations: normal washing in water at a temperature of about 40°C, using liquid detergents without bleaches or dyes.

New line of eVent materials

Since 2013, the eVent membrane range has been completely redesigned. Today, eVent materials are divided into three groups:

waterproof- waterproof fabrics; windproof- windproof fabrics; professional- fabrics for professional use.

All eVent materials are based on Direct Venting technology, so the names of new materials now begin with the abbreviation DV.

eVent fabrics allow the body to remain in a comfortable zone. The fumes escape directly to the outside of the fabric.

eVent– the world’s only porous hydrophobic Teflon membrane with integrated oleophobic protection.

Peculiarities:
- High moisture resistance;
- Excellent breathability;
- Unlike porous and combined membranes, it removes evaporation directly without diffusion through a non-porous membrane;
- Works better than other moisture-proof membranes at high external humidity;
- Works better than other membranes at sub-zero temperatures on the membrane;
- Reduces the likelihood of overheating compared to conventional membranes.

Structure of the eVent Teflon membrane

eVent® fabrics let the sweat out™

Comparison of eVent membrane with a combination membrane

Direct Venting™ technology

The fumes escape directly to the outside of the fabric.

Works at any temperature and relative humidity inside.

Precursors based on polyurethane membranes

This membrane needs to become wet before it begins to remove moisture.

The polyurethane membrane requires more high temperature inside.
A polyurethane membrane requires higher humidity inside.
The polyurethane membrane requires a higher partial pressure from the inside.

In the comfort zone with eVent fabrics

eVent fabrics allow the body to remain in a comfortable zone.

For a long time, eVent was laminated onto fabric exclusively at the production of the Japanese company Mitsui. Since 2010, the eVent membrane began to be laminated to fabric in a variety of production facilities different levels, including in South Korea and China.

The properties of the laminate are determined by the selection of fabrics and the perfection of lamination technologies. There are many products with eVent membrane on the market, differing significantly in cost and actual functionality.

Since 2011, GE, the membrane manufacturer and owner of the rights to the eVent Brand, has allowed manufacturers to use their own Brand-name for fabrics with the eVent membrane. There is currently on the market a large number of membrane materials based on eVent technology and under different trademarks.
Most of them are inferior in their properties to the classic eVent from Mitsui.

An idea of ​​the functionality of a particular material can be made based on studying its characteristics: moisture resistance and breathability.

eVent Pro

New exclusive material developed in accordance with our requirements, taking into account latest trends development of membrane materials and progress of technology.

Careful selection of fabrics and improvement of the lamination process made it possible to obtain a new generation of material.

eVent Pro surpasses the classic eVent in almost all comparison indicators: moisture resistance, breathability, durability of the inner layer, softness.

*Data for eVent 3L, manufactured by Mitsui, used in Torok and Az Torok models.

Comparison of the inner surface of three-layer membranes

Classic eVent 3L Knitted structure.

eVent Pro 3L Woven structure. Wear resistance is much higher.

Features of eVent Pro 3L:
- Maximum breathability of all membranes with moisture resistance above 20000mm - MVTR A1 10000 g/m2/24h, MVTR B1 32000 g/m2/24h;
- Maintains efficiency with a small difference in partial pressures of water vapor, which provides a high level of comfort during prolonged precipitation and active movement;
- Due to the effective transport of water vapor, it prevents overheating during movement;
- High moisture resistance 40,000 mm;
- Durable woven laminate inner layer;
- Durable nylon upper material;
- Made in Japan.