Medium density polyethylene is elastoplastic material.

the polythene sheet behave as elastic or elastoplastic is not only depends on the density of the sheet but also the tensile strength..however, the behaviour of sheet within elastic or elastoplastic is also depends on whether the material stressed within the maximum tensile strength or not. If within the strength than the behaviour is elastic or otherwise elastoplastic..ok all the best..

Mostly is behaved as elastplastic material.

Moataz A. Al-Obaydi , Karthigeyan . S and Serge V. Shil’ko thank u very much. cleared