In order to obtain a good pulp with suitable qualities for wrapping purpose, the bagasse should be sufficiently depithed before digestion and also the SiO₂ in the black liquor be removed.
The usual differences between bagasse pulp and wood pulp of the same freeness are as follows:-
1. Extracts with 10% NaOH sol : greater
2. Beating time : shorter
3. Bursting resistance : higher
4. tearing resistance : slightly lower
5. Folding endurance : higher
6. Opacity : lower

View full abstract

Powdered Cellulose is high alpha-pulp hydrolyzed to the crystalline region and pulverized by mechanical process. High-alpha was hydrolyzed with nitric acid and the effects of hydrolytic conditions (concentration of nitric acid, time and temperature) on the degree of polymerization and carboxyl content of the hydrolyzed pulp were examined mainly from the standpoint of the manufacture of powdered cellulose.
(1) From the viewpoint of the degree of polymerization of the hydrolyzed pulp, the suitable concentration of nitric acid is about 5 to log (10g) /100cc and the suitable time of hydrolysis is about 0.5 to 1 hour at the hydrolytic temperature of 90°C. It is possible to reuse the spent liquor by making up for the loss of nitric acid of the previous hydrolytic process.
(2) In case of the hydrolysis with nitric acid solution at the concentration of 0.1 g/100 cc at the hydrolytic temperature of 150°C and treatment of 3 hours, the degree of polymerization of the hydrolyzed pulp is nearly equal to that of the pulp hydrolyzed at 90°C, 10 g nitric acid/100 cc and 3 hours.
(3) Only a little formation of acidic oxidized cellulose takes place at the mentioned hydrolytic processes with dilute (under 10 g/100 cc) nitric acid.
(4) The stronger the condition of nitric acid treatment is, the easier pulverizes the acid treated cellulosic fibre and the more crack can be observed on the surface of the fibre.

View full abstract

Peracetic acid has been shown to be an effective agent for the bleaching of chemical and mechanical pulps. To gain a better understanding the mechanism of delignification during pulp bleaching, the degradation by Peracetic acid of some aromatic compounds, such as vanillyl alcohol, guaiacylmethyl carbinol, vanillin, acetovanillone, vanillic acid and protocatechuic acid, was carried out in the agent solution at 35°C for a prolonged period.
The main degradation products obtained in this way were vanillin, protocatechualdehyde, 2-methoxy-p-hydroquinone and 2-methoxy-p-benzoquinone from vanillyl alcohol and guaiacylmethyl carbinol. It also appears that the formation of acetovanillone from guaiacylmethyl carbinol was accelerated in a Peracetic acid solution. On the other hand, the products, such as 2-methoxy-p-hydroquinone and 2-methoxy-p-benzoquinone were formed from vanillin and acetovanillone under the same conditions. But, the formation of protocatechiuc acid from acetovanillone by peracetic acid was not identified. The small amounts of muconic, malefic and oxalic acids were found in the all aromatic compound solutions after peracetic acid degradation.
From above results, a scheme for the main oxidative degradation by Peracetic acid of some aromatic compounds used was suggested (shown in Fig. 6).

View full abstract