ABSTRACTGaskets are used as interfacing element between the mating surfaces, to seal the flange joint. The interfacing elements are usually subjected to compression during loading and relaxation during unloading. The unloading behaviour of the gasket material, when subjected to internal fluid pressure, controls the residual deformation in gasket. A methodology is proposed to obtain the homogenised behaviour of heterogenous gasket by volume averaging the response from micromechanical analysis. The response includes both loading and unloading characteristics of the gasket material. Here, the individual constituents’ characteristics in the spiral wound gasket is modelled using their respective elasto-plastic behaviour. But the unloading behaviour is more affected by the plastic properties. Therefore, the anisotropic Hill’s plastic parameters are evaluated by analysing the representative volume element of the gasket under different loading conditions. The compressive behaviour of the spiral wound gasket from homogenisation is compared with the experimental values for both loading and unloading conditions. An improved unloading behaviour is obtained using the proposed methodology.