Biodegradable starch films as an environmentally friendly packaging materials: printing performance
Biodegradable starch films can be a great alternative for non-degradable conventional plastic films as packaging materials. Packaging material, besides relevant properties such as mechanical or barrier properties, should also be characterised by a good printability to provide some required information about the product. In this study we show the possibility of printing of starch films. Potato starch films with glycerol as a plasticiser were obtained. The properties of the films were confirmed by tensile strength, water vapour transition rate, and moisture content. Next, the surface free energy of the starch films was determinate by the Owens−Wendt and van Oss–Chaudhury–Good approach. The wettability of the obtained films was investigated by the analysis of water droplet absorption. Finally, the films were overprinted with biodegradable printing ink and optical density and colour parameters were determined. The printing performance was compared with biodegradable commercially available PLA and paper. The print quality of the overprinted starch films is comparable to the PLA and paper, which shows the strong potential of using starch films as a biodegradable, environmentally friendly packaging materials.