Nikwax Analogy
Encyclopedia
Nikwax Analogy is a two-component fabric system for weatherproof clothing based on "biomimicry" of fur
(the system was originally called "Nikwax Biological Analogy").
Unlike a conventional waterproof fabric
, Analogy would fail a hydrostatic head
test (if used to seal the bottom of a tube containing water, only a very short column could be supported). However, like fur, Analogy causes water to flow away from the body of the wearer and with water typically moving out faster than it arrives the garment is effectively waterproof from the wearer's point of view. Without a formal seal required, Analogy does not need the taped seams required by e.g. Gore-Tex
rain-wear, and punctures in the outer layer do not compromise the action of the twin-component design.
The "pump" layer and the shell fabric both rely on a Durable Water Repellent
treatment; this treatment in combination with the fabric structure of the "pump" layer creates the capillary depression effect that allows water to be driven away from the wearer. In common with other waterproof garment technologies, this water repellent treatment must be maintained in order to remain effective.
Clothes made from Analogy can also be heavy compared to many examples of waterproof "hard shells" (but not necessarily to the combined weight of these and an insulating layer) and are relatively expensive. Though the veracity of this may depend on the system it's compared to, as for many applications it means that less overall items need to be carried, potentially reducing the total garment count and expendature.
The weight issue has been addressed by the production of Nikwax Analogy Light which uses a lighter windproof outer with the same Pump Liner fabric, resulting in garments that are 19-20% lighter than the same style made in standard Analogy fabric. Examples of these are the Velez Adventure Light Smock, the Quito Jacket, the Vista Jacket and the Velez Adventure Trousers.
The high "breathability" of the system makes it more suitable than conventional "hard shell" waterproofs for general use, as opposed to only being used in foul weather. This can offset the extra weight of the system, as extra garments for different conditions are less likely to be required.
Similar twin fabric systems are used by Furtech and Finisterre, though not using fabrics sourced from Nikwax.
Fur
Fur is a synonym for hair, used more in reference to non-human animals, usually mammals; particularly those with extensives body hair coverage. The term is sometimes used to refer to the body hair of an animal as a complete coat, also known as the "pelage". Fur is also used to refer to animal...
(the system was originally called "Nikwax Biological Analogy").
Technology
The key to the system is the inner "pump" layer which is designed to move moisture from one face to the other by means of capillary depression (a surface tension effect causing fluid to move along a tube in the direction of increasing diameter). Combined with an outer layer that slows down incoming rain and wind, the "pump" layer is able to push water away from the wearer at a rate which should keep them dry. Since both components of the system are, by themselves, porous and air-permeable, the Analogy system is considerably more breathable than waterproofs relying on a non-porous layer. Unlike most "waterproof breathable" fabrics, Analogy can pass out liquid water as well as vapour.Unlike a conventional waterproof fabric
Waterproof fabric
Waterproof fabrics are fabrics that are inherently, or have been treated to become, resistant to penetration by water and wetting. They are usually natural or synthetic fabrics that are laminated to or coated with a waterproofing material such as rubber, polyvinyl chloride , polyurethane , silicone...
, Analogy would fail a hydrostatic head
Hydrostatic head
When generating hydropower, the head is a general term used to describe the distance that a given water source has to fall before the point where power is generated. Ultimately the force responsible for hydropower is gravity, so a hydroelectricity plant with a tall/high head can produce more...
test (if used to seal the bottom of a tube containing water, only a very short column could be supported). However, like fur, Analogy causes water to flow away from the body of the wearer and with water typically moving out faster than it arrives the garment is effectively waterproof from the wearer's point of view. Without a formal seal required, Analogy does not need the taped seams required by e.g. Gore-Tex
Gore-Tex
Gore-Tex is a waterproof/breathable fabric, and a registered trademark of W. L. Gore and Associates. It was co-invented by Wilbert L. Gore, Rowena Taylor, and Gore's son, Robert W. Gore. Robert Gore was granted on April 27, 1976, for a porous form of polytetrafluoroethylene with a...
rain-wear, and punctures in the outer layer do not compromise the action of the twin-component design.
The "pump" layer and the shell fabric both rely on a Durable Water Repellent
Durable Water Repellent
DWR is a coating added to fabrics at the factory to make them water-resistant . Most factory-applied treatments are fluoropolymer based. 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...
treatment; this treatment in combination with the fabric structure of the "pump" layer creates the capillary depression effect that allows water to be driven away from the wearer. In common with other waterproof garment technologies, this water repellent treatment must be maintained in order to remain effective.
Characteristics
A factor of the two-fabric system is that it inevitably adds insulation, due to the requirement of the inner "pump" liner: being a fur substitute with a definite and designed structure it traps air as well as channeling water, which has an insulating effect. While this can be useful in cooler conditions it is less suitable for higher temperature and/or high activity conditions where overheating is more of a problem than an alternative which provides less insulation. Adding venting features to garments helps address this problem, but it is only a partial solution.Clothes made from Analogy can also be heavy compared to many examples of waterproof "hard shells" (but not necessarily to the combined weight of these and an insulating layer) and are relatively expensive. Though the veracity of this may depend on the system it's compared to, as for many applications it means that less overall items need to be carried, potentially reducing the total garment count and expendature.
The weight issue has been addressed by the production of Nikwax Analogy Light which uses a lighter windproof outer with the same Pump Liner fabric, resulting in garments that are 19-20% lighter than the same style made in standard Analogy fabric. Examples of these are the Velez Adventure Light Smock, the Quito Jacket, the Vista Jacket and the Velez Adventure Trousers.
The high "breathability" of the system makes it more suitable than conventional "hard shell" waterproofs for general use, as opposed to only being used in foul weather. This can offset the extra weight of the system, as extra garments for different conditions are less likely to be required.
Clothes and Market
The main user of Analogy is Nikwax's sister company Paramo with some other small specialist suppliers (such as Hilltrek and Cioch Direct) also producing garments from it. While Analogy clothes have a dedicated following among UK mountaineers, Paramo distribution and marketing to the mass market and outside the UK seems to be extremely limited.Similar twin fabric systems are used by Furtech and Finisterre, though not using fabrics sourced from Nikwax.