Sealskinz Mid Thermal Waterproof Sock

Outdoor Clothing UK > Sealskinz Mid Thermal Waterproof Sock

Sealskinz Mid Thermal Waterproof Sock
Sealskinz Mid Thermal Waterproof Sock Ref: 200

RRP £30.00
Price £24.95

Delivery Time: 3 Days

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Colour: Black

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Product Description


SealSkinz® are the world's only range of waterproof, breathable, close-fitting socks. Suitable for a wide variety of uses, from outdoor pursuits to gardening, you're sure to stay dry with SealSkinz® on!

Using a high density loop pile padded layer of Merino wool as a lining, the Mid Thermal is the warmest SealSkinz sock available and is available in both black and olive green.

Mid calf length.
Waterproof and breathable
Seamless for increased comfort
Stretch technology to ensure a perfect fit.

Inner: Merino wool and nylon lycra make this sock very comfortable. It is warm and wicks away moisture for maximum comfort.

Membrane: Porelle P540 Black

Outer: Acrylic/ Elastine. This is fast drying and very durable.

Sealskinz Socks Sizing Chart

Small: 5 - 7

Medium: 7 - 9

Large: 9 - 11

Sealskinz - How do they work?

Waterproof and breathable Socks - Why both ?

Sealskinz waterproof Socks need to be both waterproof AND breathable. A totally waterpoof but non-breathable sock would be very uncomfortable to wear, as perspiration (as water vapour) would have no means of escaping, thus condensing on the inside of the garment, leaving the wearer 'wet from within' and feeling cold.

Conversely a very breathable but non-waterproof sock would be so open, allowing air, and perspiration (as water vapour) to pass freely through, that it would offer little protection from the elements (e.g. canvas tents let water through if you lean against them!)

Types of Waterproofing ...

There are two commercial ways to make a fabric resist water:

Some garments are made water-resistant by coating the outer surface with a layer of hydrophobic ("water hating") chemical or wax. When water droplets fall onto the fabric they "bead" due to the surface tension of the water, and roll off. However, coatings are not always durable, and can be damaged during repeated washing and flexing (wear)

A more durable method is to use a waterproof breathable film or "membrane", which is laminated (‘glued’) to a layer of fabric inside the garment. SealSkinz® waterproof socks and hats incorporate a Porelle membrane which is laminated between the inner and outer layers. Porelle membrane is both waterproof AND breathable, and will never wash away.

Waterproof Membranes

There are two types of polyurethane film used to make waterproof breathable socks:

1. Microporous ...

Microporous films are full of microscopic holes or pores. These pores are approximately 5 microns in diameter whereas water droplets are typically 500 - 5000 microns and 'drizzle' droplets can be as small as 200 microns in diameter and are therefore too large to penetrate the pores in the film. It is impossible for water droplets to pass through, and therefore the film is 100% waterproof.

Water vapour molecules, generated by the body perspiring, are much smaller (typically less than 0.0003 microns) and pass easily through the holes, carrying moisture away.

2. Hydrophilic ...

SealSkinz® socks and gloves use a different type of membrane called hydrophilic ("water loving"). Hydrophilic membranes are totally solid, without pores. It is therefore physically impossible for droplets of liquid water to pass through the membrane, however, it is breathable because water vapour molecules are transmitted from molecule to molecule through the membrane on the polymer chain and expelled on the other side. The driving forces are the differences in humidity and temperature between the atmospheres on each side of the film.

The internal climate, next to the skin, is hot and humid because the body is generating heat and moisture as it exercises. The external climate is much drier and cooler. Consequently water vapour is driven from the inside of the garment to the outside. As the foot gets hotter during an activity, so the film becomes more efficient at expelling moisture.

SealSkinz® 100% Waterproof Testing …

Every single SealSkinz® product is tested before it leaves the factory. The hat is mounted onto a machine which subjects it to water pressure. If any product leaks, the item is rejected and diced. Every SealSkinz® product is therefore guaranteed to be 100% waterproof.

The waterproof film can withstand 10psi of hydrostatic head pressure, the equivalent of a column of water 700cm high standing on the fabric surface. This is 7 times the level required to meet European Standards for waterproof clothing.

Breathability Index.

Breathability is measured by a water vapour permeability index in accordance with BS 3424: Part 34: 1992 Method 37. In this test, pieces of laminated fabric cover a small cup holding a measured mass of water.

The cup is allowed to stand in a controlled climate for several hours. At the end of the test, the cup is re-weighed to determine how much moisture from within the cup has evaporated and been expelled through the sample fabric.

A water vapour permeability (WVP) rating is then determined by comparison to a standard fabric given the same treatment. The SealSkinz® Mid light, Long light, Mid thermal and the New SealSkinz Glove all have a water vapour permeability index of 50-60% when measured in accordance with BS 3424: Part 34: 1992 Method 37.
Outdoor Clothing UK > Sealskinz Mid Thermal Waterproof Sock