Together with the wire brushes mounted on the TBM tail, tail seal grease forms an impermeable barrier against the ingress of annulus grout, water or soil into the TBM. Tail seal greases need to be highly water-resistant with excellent adhesion to metal surfaces, while remaining easily pumpable. A unique combination of different fibre types, special oils and fillers ensures well-balanced tail sealant performance combined with the lowest possible impact on the environment.
First fill grade tail seal grease is pumped into the wire brushes before the TBM starts up. Once applied inside the brushes, the first fill grade protects them against wear, water soil and annulus grout ingress while keeping the brushes highly flexible for protect long-term sealing.
Driving grade tail seal grease is pumped into the sealant chambers as the TBM advances.
High Performance Tail Sealant for TBMs (Driving Grade)