Investigation on the Utilization of Chemi-Mechanical Pulp from Wheat Straw for Fluting Paper Production

Development of wheat straw chemi-mechanical pulping to produce pulp which can partially substitute OCC pulp and suitable for small scale implementation was investigated. Four levels (10، 12، 14 and 16% based on oven dry weight of straw) of NaOH at pulping time of 40 minutes and 95°C pulping temperature were used. After digester yield varied between 64. 6 and 72. 7% and the total yield after defibration was measured as 55. 45% and 58. 3%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps were refined to about 350 ml CSF in a PFI mill and then hand sheets were made for strength evaluation. The apparent density of the hand sheets varied between 437and 488 kg/m3، tear index between 6. 51 and 7. 11 mN. m2/g، and tensile index between 29. 2 and 30. 8 N. m/g. Statistically significant difference at 99% level was not observed between the strength values of the pulps. Wheat straw pulp produced applying 10% NaOH، 40 minutes pulping time at 95°C was used as the substitute pulp for Old Corrugated Container pulp. The characteristics of the pulp refined to 365 ml CSF was superior to OCC pulp which indicates that it can be used as reinforcing pulp for OCC.