Chemical characteristics and Kraft pulping response of Phyllostachys pubescens stems -: Comparison with kenaf bast, Japanese softwood and fast-growing hardwood

Recently, it has been reported that bamboo is sometimes used as a raw material in some of kraft pulp mills. However, there are few findings on relationships between chemical features and cooking or bleaching response. In this study, Phyllostachys Pubescens which was obtained in Ibaraki prefecture was chemically analyzed, and kraft-cooked and bleached by totally chlorine-free (TCF) bleaching. In addition, P pubescens stems were compared with Hibiscus cannabinus bast, Cryptomeria japonica D. Don wood and Eucalyptus grandis wood. The lignin content of P pubescens stems was similar to that of E grandis wood, and the xylan content of P pubescens was high compared with the other materials. In obtaining pulps with given kappa numbers, the delignification response of P pubescens was equal to that of E grandis and better than that of H cannabinus bast. However, the pulp yield of P pubescens was lower than that of E gradis or H cannabinus bast, and was equal to that of C japonica. The hexenuronic acid content of P Pubescens kraft pulp was lower than that of H. cannabinus bast or E grandis. The brightness of unbleached pulp prepared from P pubescens was far higher than that from H cannabinus and E grandis. The P pubescens pulp gave higher brightness after oxygen bleaching than the H. cannabinus or E grandis pulps.