With the Dryflex® WS range we have turned the usual water-resistant properties of thermoplastic elastomers (TPE) on their head to create materials that swell up to ten times their volume when immersed in water. These materials have been developed to expand upon contact with aqueous solutions (pH7 to 12) to form a positive seal and prevent the ingress or exit of water.

Material Science
A range of formulations have been developed which offer different swell rates when immersed in water. When there is no longer water present the compound shrinks back to its original size, a process of expansion and contraction that can be repeated an unlimited number of times.

The compounds have solid structural integrity; unlike many of the equivalent clay based products which can erode and shatter over time. Compounded in any colour, the water swellable TPE is 100% recyclable and can be processed using conventional fabricating methods, including extrusion and injection moulding. Antimicrobial versions are available.

Applications
One of the main applications for Dryflex WS compounds are hydrophilic waterstops. These are typically used as part of a concrete structure and intended to prevent the passage of fluids (e.g. water) when embedded in and running continuously through concrete joints.

We have developed softer grades which offer excellent drapability. They are an ideal choice for waterstops where the profiles may be coiled or need to be fitted around complex structures.

Other applications for Dryflex WS TPE compounds include tunnels, water treatment plants, drains, sewers,
tanks, glazing and cable protection.