Temperature-induced alterations of the structure and mechanical properties of cork

When cork is heated in air at temperatures in the interval 100–300°C, it swells and its mass decreases. In this paper a detailed study of the effects of heat treatment on the structure, overall dimensions, mass and compression properties of cork (reproduction and virgin cork) is reported. It is observed that the lenticular channels swell while the originally corrugated cell walls become straight. These structural changes, together with the chemical alteration of the cell wall material, explain the observed effects on the mechanical properties.