Lately, one of the largest road tunnel projects under construction in the world, the road tunnels in Stockholm, Sweden, used RoadStar, the tunnel waterproof structure fixture co-developed by KraussMaffei.

During the construction, grid-shaped, bendable, and elastic supporting structure fixture need to be laid between the rock layer and the waterproof membrane. The traditional material is metal, and the service life is only about 50 years. KraussMaffei has facilitated the Norwegian company Oldroyd to successfully develop RoadStar, a new structural member made of thermoplastic elastic plastic and polyethylene. This product not only has high sealing performance, strong impact resistance, and a test life of up to 120 years, and its raw materials come from marine plastic waste such as damaged fishing nets and plastic ropes, which produces good economic and social benefits.

In this project, KraussMaffei’s equipment and process can effectively address viscosity changes caused by variation in material composition, and maintain a stable injection volume to ensure product consistency and high quality. In the meantime, KraussMaffei’s super-large LRX robot can deliver automatic production unattendedly, further improving efficiency and capacity. At present, RoadStar products have been put into application in multiple tunnel constructions.