Influence of Temperature and Airflow on the Mechanical Behavior of Multigraphene Sealing Materials

This study investigates the influence of the thermal expansion parameters during the production of a multigraphene-based composite gasket on its performance properties. Under laboratory conditions (near-laminar flow), compared with 700 °C, expansion at 1000 °C increased recovery from 7.5 to 9.2% and tensile strength from 3.8 to 5.6 MPa. For continuous industrial-scale production, MGS was pneumatically transported to increase process productivity. At the expansion temperature of 1000 °C, the material obtained under these conditions exhibited lower mechanical performance than that produced in the laboratory-scale process. The transport parameters themselves also had a measurable effect on the resulting properties. At pressures of 0.2 and 0.6 MPa, recovery increased from 8.6 to 9.1%, while tensile strength increased from 3.4 to 3.7 MPa. The highest recovery (10.0%) was obtained at a feed pipe insertion depth of 100 mm within the investigated range of 50–200 mm. Increasing the feed pipe diameter from 8 to 16 mm also improved the mechanical performance, with recovery increasing from 9.0 to 10.4% and tensile strength from 3.7 to 5.4 MPa. The experimental results, supported by thermal and gas-dynamic simulations, show that processing conditions alter the length, tortuosity, and fragmentation of multigraphene structures before compaction, which in turn affects the mechanical performance of the final material. These results establish a link between thermal and gas-dynamic processing conditions and the mechanical properties of CMGMs, providing a basis for optimizing their continuous production for sealing applications.