Waterproof fabric

Last updated December 03, 2023

A wax coating makes this Manila hemp waterproof 49-QWSTION-BANANATEX-FABRIC.jpg — A wax coating makes this Manila hemp waterproof

Waterproof fabrics are fabrics that are, inherently, or have been treated to become, resistant to penetration by water and wetting. The term "waterproof" refers to conformance to a governing specification ^[1] and specific conditions of a laboratory test method. They are usually natural or synthetic fabrics that are laminated or coated with a waterproofing material such as wax, rubber, polyvinyl chloride (PVC), polyurethane (PU), silicone elastomer, or fluoropolymers. Treatment could be either of the fabric during manufacture or of completed products after manufacture, for instance by a waterproofing spray. Examples include the rubberized fabric used in Mackintosh jackets, sauna suits, and inflatable boats.

Definition and specifications

Waterproof/breathable fabrics resist liquid water passing through, but allow water vapour to pass through. Their ability to block out rain and snow while allowing vapour from sweat to evaporate leads to their use in rainwear, waterproof outdoor sports clothing, tents, and other applications.

Standard laboratory testing protocols ^{[ which? ]} define the performance of these fabrics. Water resistance is measured by the amount of water, in mm, which can be suspended above the fabric before water seeps through.^{[ citation needed ]} Breathability or moisture vapor transmission rate is measured by the rate at which water vapor passes through, in grams of water vapour per square meter of fabric per 24-hour period (g/m²/d),^[2] often abbreviated to just "g". In recent years ^{[ timeframe? ]} some,^{[ who? ]} but not all, sporting goods manufacturers have begun including this information on their product labels. Typical mid-range fabrics tend to have values of 5,000 mm of water resistance and 5,000 g of breathability; the best materials have 20,000 mm and 20,000 g.

One specific definition of "waterproof/breathable" requires the fabric to withstand a pressure of over 1,000 millimetres of water (9.8 kPa) pressure without leaking (see hydrostatic head).^{[ citation needed ]}

These values should be taken with some caveats. Rain room tests show that some fabrics with less than 1,000 mm of water resistance keep water out sufficiently for practical purposes.^{[ citation needed ]} Garments made from these fabrics tested in the Leeds University Rain Room show no signs of leakage after 4 hours of simulated rain five times heavier than heavy rain.^{[ clarification needed ]} However, some garments made from fabrics that exceed 20 000 mm have leaked through zips, hoods, and seams. Fabric head ratings do not totally specify water resistance of a garment, as it does not test closures such as zips. In addition, the breathability of nearly all waterproof/breathable fabrics is very dependent upon weather conditions, especially temperature, humidity, and wind.^{[ according to whom? ]}

Directional fabrics

Fabric construction which directs water away from the body, rather than membranes, coatings, or laminates, can be used to keep the wearer dry. This means that perspiration can be moved away from the body more effectively, as both liquid water and water vapour can be directed. These are directional fabrics such as Nikwax Analogy and FurTech, which are also breathable in the conventional sense (although these examples are actually a combination of two different fabrics, a directional "pump" layer underneath a distinct windproof and water-resistant outer layer; while effectively completely waterproof against rain, they would fail a strict hydrostatic head test as given in the definition above).

In combination with thermal insulation

Garments that combine waterproofing with some thermal insulation, such as those manufactured by FurTech and Nikwax Analogy, resist cold bridging, heat transferred through layers of poorly-thermally-insulating materials in close contact that would be prevented by a small airspace. When there is cold bridging, vapour on the dry side can condense on the cold surface, making it appear that the thin waterproof breathable fabric has leaked.

Related Research Articles

A wetsuit is a garment worn to provide thermal protection while wet. It is usually made of foamed neoprene, and is worn by surfers, divers, windsurfers, canoeists, and others engaged in water sports and other activities in or on water. Its purpose is to provide thermal insulation and protection from abrasion, ultraviolet exposure, and stings from marine organisms. It also contributes extra buoyancy. The insulation properties of neoprene foam depend mainly on bubbles of gas enclosed within the material, which reduce its ability to conduct heat. The bubbles also give the wetsuit a low density, providing buoyancy in water.

Gore-Tex is a waterproof, breathable fabric membrane and registered trademark of W. L. Gore & Associates. Invented in 1969, Gore-Tex can repel liquid water while allowing water vapor to pass through and is designed to be a lightweight, waterproof fabric for all-weather use. It is composed of stretched polytetrafluoroethylene (PTFE), which is more commonly known by the generic trademark Teflon. The material is formally known by the generic term expanded PTFE (ePTFE). Gore-Tex products free of "PFC of environmental concerns" repellent coating lacks the ability to repel oil that "Gore DWR" provided.

<span class="mw-page-title-main">Raincoat</span> Waterproof coat

A raincoat is a waterproof or water-resistant garment worn on the upper body to shield the wearer from rain. The term rain jacket is sometimes used to refer to raincoats with long sleeves that are waist-length. A rain jacket may be combined with a pair of rain pants to make a rainsuit. Rain clothing may also be in one piece, like a boilersuit. Raincoats, like rain ponchos, offer the wearer hands-free protection from the rain and elements; unlike the umbrella.

<span class="mw-page-title-main">Gabardine</span> Tough, tightly woven fabric used to make suits, trousers and some other garments

Gabardine is a durable twill worsted wool, a tightly woven fabric originally waterproof and used to make suits, overcoats, trousers, uniforms, windbreakers, outerwear and other garments.

Waterproofing is the process of making an object or structure waterproof or water-resistant so that it remains relatively unaffected by water or resisting the ingress of water under specified conditions. Such items may be used in wet environments or underwater to specified depths.

Durable water repellent, or DWR, is a coating added to fabrics at the factory to make them water-resistant (hydrophobic). Most factory-applied treatments are fluoropolymer based; these applications are quite thin and not always effective. Durable water repellents are commonly used in conjunction with waterproof breathable fabrics such as Gore-Tex to prevent the outer layer of fabric from becoming saturated with water. This saturation, called 'wetting out,' can reduce the garment's breathability and let water through. As the DWR wears off over time, re-treatment is recommended when necessary. Many spray-on and wash-in products for treatment of non-waterproof garments and re-treatment of proofed garments losing their water-repellency are available.

Moisture vapor transmission rate (MVTR), also water vapor transmission rate (WVTR), is a measure of the passage of water vapor through a substance. It is a measure of the permeability for vapor barriers.

SympaTex is a type of fabric that is branded as waterproof but "breathable", made or licensed by SympaTex Technologies GmbH a company founded in 1986. The fabric features a waterproof, windproof and breatheable membrane that is laminated to fabrics either on its inner surface or sandwiched between two fabric layers. The latter system offers greater durability, by better protecting the integrity of the SympaTex layer from abrasion to both the outside and the inside of the garment.

Windstopper is a windproof breathable fabric laminate made by W. L. Gore & Associates. One of its most common applications is a lamination with polar fleece, to compensate for fleece's lack of wind resistance.

A tuilik is an Inuit watertight jacket, used when paddling a kayak. It is sealed at the face, at the wrists and around the cockpit coaming. In this way the paddler can capsize and come back upright without getting wet, and without getting any water into the kayak.

Layered clothing is the wearing of multiple garments on top of each other.

The Extended Cold Weather Clothing System is a protective clothing system developed in the 1980s by the United States Army Natick Soldier Research, Development and Engineering Center, Natick, Massachusetts. The first generation ECWCS consisted of parka and trousers plus 20 other individual clothing, handwear, headwear and footwear items which are used in various combinations to meet the cold weather environmental requirements of the US military. The Extended Climate Warfighter Clothing System, or Gen III ECWCS, is designed to maintain adequate environmental protection in temperatures ranging between -60° and +40° Fahrenheit

Ventile, is a registered trademark used to brand a special high-quality woven cotton fabric first developed by scientists at the Shirley Institute in Manchester, England. Originally created to overcome a shortage of flax used for fire hoses and water buckets, its properties were also useful for pilots' immersion suits, but expensive and leaky if exposed to sweat or oils.

Robert W. Gore was an American engineer and scientist, inventor and businessman. Gore led his family's company, W. L. Gore & Associates, in developing applications of polytetrafluoroethylene (PTFE) ranging from computer cables to medical equipment to the outer layer of space suits. His most significant breakthrough was likely the invention of Gore-Tex, a waterproof and breathable fabric popularly known for its use in sporting and outdoor gear.

Breathability is the ability of a fabric to allow moisture vapor to be transmitted through the material.

Nikwax Analogy is a two-component fabric system for weatherproof clothing based on "biomimicry" of fur.

Waxed cotton is cotton impregnated with a paraffin or natural beeswax based wax, woven into or applied to the cloth. Popular from the 1920s to the mid-1950s, the product, which developed from the sailing industry in England and Scotland, became commonly used for waterproofing. It has been replaced by more modern materials but is still used by the country sports community. The main drawbacks are two: waxed fabric is not very breathable, and it tends to be heavier and bulkier than modern synthetic waterproof materials.

Páramo Directional Clothing is a British outdoor clothing company. It was founded by Nick Brown, who also started the Nikwax waterproofing products company.

<span class="mw-page-title-main">Oilcloth</span> Type of cloth with a waterproof coating

Oilcloth, also known as enameled cloth or American cloth, is close-woven cotton duck or linen cloth with a coating of boiled linseed oil to make it waterproof.

Textile performance, also known as fitness for purpose, is a textile's capacity to withstand various conditions, environments, and hazards, qualifying it for particular uses. The performance of textile products influences their appearance, comfort, durability, and protection. Different textile applications require a different set of performance parameters. As a result, the specifications determine the level of performance of a textile product. Textile testing certifies the product's conformity to buying specification. It describes product manufactured for non-aesthetic purposes, where fitness for purpose is the primary criterion. Engineering of high-performance fabrics presents a unique set of challenges.

References

↑ ASTM D3393-Standard Specification for Coated Fabrics – Waterproofness
↑ "Water Vapour Transmission Rate Measurements". National Physical Laboratory. 1 June 2011. Archived from the original on 13 April 2014. Retrieved 23 May 2017.

External links

"Breathability" comparison of commercial outerwear shell layers, Phil Gibson, 2000, Materials Science Team, United States Army Soldier Systems Center
Water Resistant vs Waterproof – What's the Difference? Allthingswaterproof.com Article 2016

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[1] ASTM D3393-Standard Specification for Coated Fabrics – Waterproofness

[2] "Water Vapour Transmission Rate Measurements". National Physical Laboratory. 1 June 2011. Archived from the original on 13 April 2014. Retrieved 23 May 2017.

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