Composite Multigraphene Gaskets with Ultra-Reduced Fugitive Emissions

An automatic technological line to produce a three-layer composite material based on a steel base and multigraphene tapes as fillers in spiral-wound gaskets was developed. It has been experimentally shown that multigraphene materials have a pronounced anisotropy of gas permeability due to a layered-porous microstructure. The longitudinal gas permeability of multigraphene materials obtained from intercalated graphite compounds is 20.3·10−3 mg/(m·s) for stage II and 22.9·10−3 mg/(m·s) for stage IV, while the transverse permeability is significantly lower and amounts to 0.75·10−3 mg/(m·s) for stage II and 0.85·10−3 mg/(m·s) for stage IV, respectively. The in-plane gas permeability of the composite based on stage II multigraphene is reduced to 5.8·10−3 mg/(m·s) due to the barrier effect of the metal tape. The recoverability of the composite increases to 19% with compressibility of 34%. To achieve the tightness class L0.0000001, it is proposed to manufacture spiral-wound gaskets from a three-layer composite based on stage II multigraphene with a fluoropolymer sealing coating. This made it possible to significantly reduce fugitive emissions through the composite gaskets.