Logo of the Sympatex Technologies GmbH
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
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. ...
that is
laminated to fabrics either on its inner surface or sandwiched between two fabric layers (often marketed as "3 layer laminate"). 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.
Overview
The SympaTex membrane is made of
hydrophilic
A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press.
In contrast, hydrophobes are ...
polyether-ester block
copolymer
In polymer chemistry, a copolymer is a polymer derived from more than one species of monomer. The polymerization of monomers into copolymers is called copolymerization. Copolymers obtained from the copolymerization of two monomer species are some ...
, which is closed (i.e. it has no pores). Like its more common
polyurethane
Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethane is produced from ...
equivalent, it can also be referred to as a monolithic membrane. No water can get in from the outside, but water vapour molecules are transported through the membrane from the inside to the outside by way of an absorption and evaporation process. This moisture transfer through the membrane is what is referred to as "breatheability."
A closed membrane like SympaTex differs from microporous membranes (such as
Gore-Tex
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, waterpr ...
) which have microscopic pores that let air (and water vapour) pass through, yet have such low surface energy that the surface tension of any (liquid) water in contact remains too high to allow it to squeeze through the pores. Microporous membranes have traditionally been let down by the contamination of their pores which significantly degrades their breatheability and commonly also have poorer adhesion to fabrics making them more susceptible to delamination.
SympaTex's co-polymer consists of
polyester for molecular strength, and
polyether
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...
to transport water molecules. The membrane weighs about 30g per average jacket. The membrane is at least 5 micrometres thick, translucent, and stretchable with good stretch recovery. The SympaTex membrane is completely recyclable and relatively environmentally friendly.
Fabrics
Sympatex Technologies GmbH now markets four enhanced fabrics: HigH2Out; Reflexion; Phaseable; and Airflow. It also offers 3 levels of membrane thickness for different levels of protection: Professional - heavy duty; Allweather - the standard thickness; and Windmaster - which is only 5
micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
s thick.
*HigH2Out has a more absorbent inner lining fabric in its 3 layer laminate, which over the standard SympaTex by a claimed 120%.
*Reflexion contains a coating of aluminum a few
nanometres thick, sandwiched between its membrane and lining fabric, this reflects much of the radiated heat from the human body, to preserve the user's warmth.
*Phaseable, is described as 2.5 layers, lacking a lining fabric. Small foam dots sit on the exposed inner surface of the membrane. As temperature and humidity rises the membrane expands, spreading the dots apart to reduce their insulating effect and increase the membrane's surface area, and therefore increase its moisture transfer rate (its R
et rating).
*Airflow is a laminate designed for footwear that uses a four layer lamination, with two outer layers, the inner of which consists of a knit
spacer fabric, allowing airflow and better evaporation around the outside of the membrane.
References
External links
SympaTex website
{{Fabric
Technical fabrics
B Lab-certified corporations
