TCF bleaching of kenaf (Hibiscus cannabinus) pulp for papermaking applications

Non-wood fibres are increasingly being used in the pulp and paper industry to help meet the increasing world demand for pulp and paper. Due to its short growth period, high yield and comparable physical and optical properties, kenaf is a viable and attractive non-wood fibre source alternative for soft- and hardwood fibres. Currently very little information is available on totally chlorine free (TCF) bleaching. The aim of this study was to bleach pulps to high brightness, while retaining sufficient strength properties. Peroxide reinforced oxygen (PO) and hydrogen peroxide (P) were used in the TCF bleaching of different fractions and blends of kenaf kraft pulps. A brightness of 82.4-90.4% ISO was achieved with moderate charge of peroxide. Final brightness and viscosity values showed that by using a Q(1)(PO) Q(2)P sequence, bast, core and all blend fibres can be bleached to high brightness while retaining sufficient viscosity. It was seen that bast, core and all blend fibres exhibited great strength characteristics that were suitable for papermaking.