There are a upper sealing plate and a lower sealing plate close to the two rotor lining plates. The inner hole are air holes while the fan-shaped hole of upper sealing plate and the outer hole of the lower sealing plate are material unloading hole.
The material is Polyurethane.
In rotor-type shotcrete machine, the sealing plates work with rotor lining plates as a sealing part. It is the main component of shotcrete machine, and should be checked and replaced regularly.