Normet expands range of TBM tail sealants

19 May 2020

Normet has launched what it hails as the next generation of high performance, eco-friendly tail sealants for shielded tunnel boring machines. TamSeal TG91 and TG92 are biodegradable, fire-resistant tail sealants that are formulated using plant-oil-based technology.

The new range has a lower density than previous versions and is claimed to offer improved pumpability, allowing wire-brush chambers to be filled efficiently and economically with low material consumption. Washout characteristics, adhesion and compressibility have also been optimised through vigorous testing, mitigating wire-brush leaks – even with sharp changes in tunnel alignment and demanding geologies.

Normet has further developed its new tail-sealant products with improvements in their soil conditioning technologies. The eco-friendly surfactants and polymers have been formulated to reduce cutterhead torque, improve muck-flow characteristics and ensure a homogenous material within the working chamber. The improvements are claimed to minimise production risks, maintain advancement rates through difficult strata types and offer ‘market leading’ economy.