CIPP/Relining

For the renovation of sewers, pressure pipes and drinking water networks, liners made from glass fabrics and felts are impregnated with resin, introduced in the host pipe and then cured to form a durable new pipe inside the host pipe. The two mainstream relining technologies are Light Cure (glass reinforcements impregnated with UV-curable formulations, cured by UV light) and Hot Cure (polyester felt impregnated with resin/ filler mixture, cured by steam or hot water).

The formulations used for Light Cure applications are typically thickened with MgO. After impregnation of the dry liner, the resin viscosity in the impregnated liner steeply increases as a result. As the resin remains inside the liner and does not drool out, the liners can be easily handled during transport and installation, and a uniform wall thickness of the cured pipe can be obtained. Because of the use of UV technology, the liners have excellent shelf life and can be used also in warmer climates. UV light cure equipment is typically small in size, so set-up time at installation site is short. The UV light train moves through the liner and cures the resin, which means that the technology is often very cost-effective in smaller installation lengths.

The formulations used for Hot Cure processes are typically made thixotropic. For that reason, they finished liner can also be easily handled and installed. Hot Cure liners are cooled in reefer containers or through the use of ice, in order to extend the shelf life to 1-2 weeks. The Hot Cure technology is used for smaller and bigger diameters compared to Light Cure technology, and is also more cost effective in larger lengths (shorter cure time as whole stretch is cured in one go).

AOC Products

Both for Light Cure and for Hot Cure technologies, AOC has multiple resin systems available under Synolite™, Palatal®, and Atlac® brands. The formulations can be based on Iso/ NPG, Ortho/NPG and Vinyl ester chemistries, depending on the specific performance requirements, chemical resistance, and desired pipe design life. Also, specific solutions are available for liners used in pressure pipes (cooling water, fire water) and drinking water (food contact formulations, manufactured in line with GMP).

Specific AOC resin types fulfill the requirements as defined by DIBT (Deutsches Institut für Bautechnik) Berlin for sewage liner applications.    

Using the Relining products from AOC, our clients have been able successfully to install strong pipes with over 50 years of expected working life (while in many cases these pipes may be used even much longer based on the materials’ current track record of durability). AOC has a team of experts available that can help you to further improve liner manufacturing quality, and installation effectiveness. In many cases we work together with our customers to explain the benefits of this technology to municipalities and end-customers. Because of its innovation power, AOC is increasingly applying the relining technology in new markets and applications.

More Information

For an overview of our key products, please consult the Product Selector on this web site, or download the AOC Product Selector Guide and the Atlac Product Guide. Please also read case study about Brandenburger.