Use of wastepaper for making eco-friendly cushioning materials for packing

Environment-friendly shock-absorbing materials used for packing cushions were made from the two wastepaper grades old corrugated containers (OCC) and old newspapers (ONP), using a suction forming method without pressing. The resultant plate-like cushioning materials made of OCC and ONP respectively showed superior shock-absorbing properties with lower elastic moduli compared to expanded polystyrene (EPS) and pulp mold. The new materials had many free voids in their fibre structure, producing apparent densities above 0.1 g/cm(3), higher than that of EPS (approximate to 0.03 g/cm(3)). Their apparent density was lower than that of pulp mold (approximate to 0.3 g/cm(3)) due to their greater porosity, and this high porosity apparently produced low thermal conductivity (below 0.1 W/m-K). The results show that the cushioning materials made of OCC fibres, containing more lignin than ONP, have better shock-absorbing properties than the materials made from ONP. Deterioration in fibre quality by repeated use of the wastepaper played a great role in improving shock-absorbing ability of the cushioning materials. The addition of cationic starch to the cushioning materials hardly affected their elastic modulus.