Pulping of the coir fibers from the coconut husks was undertaken to see the feasibility to use them as raw materials for soda-oxygen pulping process. In this report, the effect of oxygen on single-and two-stage soda-oxygen pulping processes were mainly investigated.
In the single-stage alkaline oxygen pulping, obtained pulp was partially defiberized without beating by cooking with 20% NaOH and Oxygen at pressure of 3.5 kg/cm
2 using rotary autoclave of 4 litter volume. However, the pulp was defiberized completely when oxygen increased to 7.0 kg/cm
2. Soda pulp without oxygen, which was obtained under the same cooking conditions, was not defiberized. The strength properties of the pulp were higher than those of the soda pulp but lower than those of the kraft pulp. The disadvantage was that pulp yield and brightness value were considerably lower than those of the soda pulp.
In the two-stage alkaline oxygen pulping, the fibers were cooked by soda pulping as the first stage, then after the obtained first stage pulp cooked again under mild conditions with 10% NaOH, at 110°C of maximum temperature and under 7.0 kg/cm
2 of oxygen. The strength properties of the pulp were similar to those of kraft pulp. The pulp yield was lower than soda pulp but higher than single-stage pulp. The brightness was so improved remarkably as higher than that of soda pulp.
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