For several months now SAERTEX multiCom has delivered its SAERTEX-LINER® with a thickened modified resin. Feedback from construction sites had been consistently positive, and users have confirmed that the development is moving in the right direction. The company is confident that the new properties of the resin are ideally suited for fast and clean routines at a building site.

The SAERTEX multiCom team works closely with users and places great value on regular feedback from its customers. One frequent point of criticism at annual training sessions for plant operators has been the viscosity of the resin. SAERTEX multiCom took this as an opportunity to develop a higher-viscosity resin for SAERTEX-LINER®. Yet it was important that optimisation of the resin system should not take place at the expense of other product properties where SAERTEX-LINER® already has a leading role in the market.

It has now been nearly a year since SAERTEX multiCom achieved a significant increase in insertion speeds for the UV curing of SAERTEX-LINER® through a modification of the resin. Obviously, these fast insertion speeds had to be maintained after modification.

The unique storage stability of UV-cured SAERTEX-LINER® – a guaranteed six-month period for all liner sizes up to DN 1200 and up to 12 mm in wall thickness – had to be unaffected by the resin modification under any circumstances.

The aim was to warrant the flexibility of SAERTEX-LINER® and thus good handling qualities during installation while also insuring the tightness of the installed liner. One major time benefit in the installation of SAERTEX-LINER® is that the setup process is significantly faster than with competing products. All these properties had to be maintained throughout the entire warranted life of the liner, i.e. up to six months (UV curing), without any changes that might result from an increased storage period. This is achieved by ensuring a certain residual flow of the resin in the liner.

“Even in the past, SAERTEX-LINER® has distinguished itself by a long storage life, high insertion speeds, fast integration and installation, rapid curing and a successful tightness test. The aim of our development was to maintain these positive qualities but also to ensure that the resin no longer leaks from the liner,” said Nils Füchtjohann, Head of Development and of the Laboratory at SAERTEX multiCom. “Thanks to the development skills which we had built up in relining and thanks to the support we received from the SAERTEX® Group, a technology leader in other areas of the composites industry (such as wind power, shipbuilding and automotive), we were in a position to examine and answer numerous questions on a laboratory scale.”

When these newly gained findings were applied to test liners, the target-focused development proved its worth. Also various initials tests in other countries have confirmed these positive results, making it possible to register the modified liner with DIBt (the German technical approval organisation for the construction industry) and to tailor the relevant production processes to the optimised resin. Mass production of the new liner for international customers could therefore be implemented quickly. In April 2011 a general permit was issued for the modified SAERTEX-LINER® by DIBt in Berlin, allowing the delivery of the product to the German market.

SAERTEX-LINER® with the new, modified resin is also being installed in a construction project that is currently conducted in Homburg by the Southwest Branch of KMG Pipe Technologies GmbH. The Homburg project includes the redevelopment of 3 km of waste water pipes DN 250 - DN 600 and egg-shaped profiles DN 400/600 using GRP pipe liner. The construction site team was requested to ensure the installation of 600 m per week. Positive confirmation was received from the Technical Manager of KMG, Holger Zinn: “Feedback from the site has been consistently positive. The SAERTEX-LINER® is easy and clean to install, and the new resin no longer leaks from the liner. Moreover, site management is as fast as ever, so we are absolutely on schedule.” Holger Zinn also emphasises that tightness is of paramount importance in Homburg and that this quality is double-checked on each installed liner – directly at the building site and then again with samples in the test lab. Commenting on the results, Zinn said: “The tests conducted so far have shown 100% density, so this is another point where we are very pleased with the quality of SAERTEX-LINER®.”

SAERTEX multiCom is determined to continue setting quality standards in GRP pipe liners and to increase user satisfaction even further.