exposing the biggest lie in the textile business

The following information is factual and gives all of the information that is necessary to understand why it is impossible for a fabric that is actually extremely waterproof and vapor permeable which there are many will not necessarily allow moisture out except in a certain situation which I will explain later in the article. The information contained here also explains why Gore-Tex and every other material stated capable of doing what Gore-Tex has claimed for years and has never done and all the rest of the pack can’t do either.

Sweat glands

The sweat gland is a long, coiled, hollow tube of cells. The coiled part in the dermis is where sweat is made, and the long part is a duct that connects the gland to the opening or pore on the skins's outer surface. Nerve cells from the sympathetic nervous system are connected to the sweat glands.

How sweat is made

We are constantly sweating, even though we may not notice it. Sweating is your body's major way of getting rid of excess body heat, which is produced by metabolism or working muscles. The amount of sweat produced depends upon our states of emotion and physical activity. Sweat can be made in response to nerve stimulation, hot air temperature, and/or exercise. First, let's concentrate on how sweat is made in an eccrine sweat gland.

When the sweat gland is stimulated, the cells secrete a fluid (primary secretion) that is similar to plasma -- that is, it is mostly water and it has high concentrations of sodium and chloride and a low concentration of potassium -- but without the proteins and fatty acids that are normally found in plasma. The source of this fluid is the spaces between the cells (interstitial spaces), which get the fluid from the blood vessels (capillaries) in the dermis. This fluid travels from the coiled portion up through the straight duct. What happens in the straight duct depends upon the rate of sweat production or flow:

Low sweat production (rest, cool temperature) - Cells in the straight duct reabsorb most of the sodium and chlorine from the fluid. This happens because there is enough time for reabsorption. In addition, water is reabsorbed osmotically. So not much sweat reaches the outside. Also, the composition of this sweat is significantly different from the primary secretion. There is not as much sodium and chloride, and there is more potassium.

High sweat production (exercise, hot temperature) - Cells in the straight portion do not have enough time to reabsorb all of sodium and chloride from the primary secretion. So, a lot of sweat makes it to the surface of the skin and the composition is close to, but not exactly like the primary secretion. The sodium and chloride concentrations are about half as much, and potassium is about 20 percent higher.

Sweat is produced in apocrine sweat glands in the same way. However, the sweat from apocrine glands also contains proteins and fatty acids, which make it thicker and give it a milkier or yellowish color. This is why underarm stains in clothing appear yellowish. Sweat itself has no odor, but when bacteria on the skin and hair metabolize the proteins and fatty acids, they produce an unpleasant odor. The maximum volume of sweat that a person who is not adapted to a hot climate can produce is about one liter per hour. Amazingly, if you move to a hot climate such as the American desert southwest or the tropics, your ability to produce sweat will increase to about two to three liters per hour within about six weeks! This appears to be the maximum amount that you can produce.

Function of sweat

When sweat evaporates from the surface of your skin, it removes excess heat and cools you. This is actually due to a neat principle in physics, which goes like this. To convert water from a liquid to a vapor, it takes a certain amount of heat called the heat of vaporization. This heat energy increases the speed of the water molecules so that they can escape into the air. For water, this value is 540 calories/gram or 2.26 x 106 joules/kilogram. So, if you can produce one liter of sweat, which is equal to 1000 g or 1 kg (density of water is 1 g/ml or 1 kg/l) in one hour, then 540,000 calories of heat can be removed from your body. This is an extreme example using the maximum amount of sweat that a person can make. Typically, all of the sweat does not evaporate, but rather runs off your skin. A major factor that influences the rate of evaporation is the relative humidity of the air around you. If the air is humid, then it already has water vapor in it, probably near saturation, and cannot take any more. Therefore, sweat does not evaporate and cool your body as efficiently as when the air is dry.

Now that you have a good understanding of sweat as I do, actually I was thinking that vapor came out of our pores but not so. Therefore the concept of vapor moving out of a garment before it is converted to liquid does not happen. In order to convert the water to a vapor heat is required and here is why I now believe when I was lost that the moisture froze on the exterior of my Antarctic parka and none inside the clothing I was wearing.

The insulation was so efficient that it trapped the heat my body was producing which was adequate to cause the change from liquid to vapor. Recently I wrote that the L-3 layer of Lamilite used in my Ducksback zippered jacket performed this task as well in milder than arctic conditions.

Note that evaporation does not happen when there is moisture in the air. What is in the air when it is raining; correct moisture! So the idea that the moist vapor coming from the inside of a garment into a moisture laden air situation cannot happen and to suggest that it can is just nonsense.

Are ALL of the companies like Gore simply ignorant of the reality of sweat or are they aware of what I have found on the internet? I personally believe they ALL know their products do not work as advertised and therefore are simply lying to the general public. I do not believe the retailers such as L.L. Bean and REI actually know the reasons that these products don’t work other than to know they don’t work anyway. So these companies and all the rest who sell these products are perpetuating the lie.

Will there ever be a time that Gore will fess up to their original lie? Will the consumer protection agency ever present fraud papers to Gore and the other companies that have been selling these materials on the pretense that they will do what they claim? Will consumers who have wasted their money on products that are made from these materials finally wake up and demand refunds and further stop buying garments made with a material that has ZERO chance of working as is advertised?

If any of the companies that market these bogus materials believes that I am wrong, you can always find me in Grand Junction, Colorado and prove me wrong!!!