SIGMA is fully stocked at all regional locations with 4 Mil High Density Cross-Laminated Polyethylene. This product, which protects ductile iron pipe from corrosion, can also be applied to underground installations of fittings, valves and other appurtenances of ductile iron pipe systems. It is defined by ANSI/AWWA C105/A21.5 as “film extruded from virgin high-density polyethylene raw material, which is then molecularly oriented by stretching. Two single-ply layers of the film are then laminated together with their orientations at 90 degrees to one another to form the final product.”
The 4 mil product, while thinner than the 8 mil polyethylene already listed in the standard, provides a few key features superior to the standard polyethylene encasement. The 4 Mil HDCL has superior puncture resistance, which can be important for rockier trench or backfill conditions. It also has superior resistance-to-tear propagation. Simply put, if snagged during installation, it is less likely to rip or tear and require repair. The 4 Mil Polywrap was added to the AWWA C105 Standard in 1993.
View the full product brochure here:
To order this and all other SIGMA products, please contact the SIGMA regional office near you: http://www.sigmaco.com/contact/