PE-RT Multilayer Pipes
Today's installer demand high performance systems to meet the ever more complicated and wide-ranging needs of their customers.
That is why PE-RT multilayer pipes are an increasingly popular choice across a range of sectors.
Drinking water systems
Combining the benefits of metal and plastic material, but avoiding the drawbacks of both, PE-RT/AL/PE-RT multilayer pipes are an ideal choice for drinking water systems. This pipe is made up of a longitude welded aluminium layer that is surrounded on the inside and outside by layers of polyethylene of raised temperature resistance. The aluminium provides excellent resistance to pressure and temperature. The inner and outer PE-RT layers inhibit scaling and corrosion whilst the addition of aluminium gives the pipe a strength which makes it an excellent alternative to copper.
Underfloor Heating Systems
In underfloor heating systems, the barrier layer usually consists of EVOH. Widely used for many years, EVOH has demonstrated a good combination of processability and barrier properties, which prevent oxygen from permeating through the pipe. A drawback of EVOH is the negative impact moisture has on the barrier characteristics. However, the industry continues to look for alternative solutions, and in the meantime uses a protective outside layer of DOWLEX™ PE-RT resins to keep the EVOH barrier functional (five layer structure pipe).
In both the EVOH and aluminium multilayer pipe versions the separate layers are bonded using an adhesive with superior performance and excellent processing characteristics.
For polyolefins those adhesives typically consist of functionalized polyolefins which adhere well to the polyolefin layer and bond via their functionality to polar layers.
It's important that the adhesive is properly prequalified as the application characteristics, extrudibility and other properties can vary quite substantially. Some adhesives perform well at room temperature, for instance, but because of their chemical structure or molecular weight distribution, may suffer dramatic losses in peel adhesion values at higher temperatures.
Depending on the technical demands the selection of the right adhesive to perform in an application can make the difference to whether the final product can meet the requirements or not.
®™* Trademark of The Dow Chemical Company ("Dow") or an affiliated company of Dow
