抄録
The effects of irradiation on 1% NaOH solubility and copper number of wood meal made from chip (A) and cold soda pulp and then the pulping yield of chip (A) were investigated.
Chip (A) was the mixed chip pf various hard wood used in pulp mill.
Cold soda pulp was made from chip (A).
The results are summarized as follow :
1) In the case of wood meal, 1% NaOH solubility and copper number which may have some relation with the alkaline peeling reaction were nearly constant up to 5×105R (roentgen).
2) 1% NaOH solubility of cold soda pulp was nearly constant up to 105R but increased at higher dosages.
3) Copper number of cold soda pulp diminished within the range of this investigation (up to 106R).
4) In comparison at the same kappa number, the pulping yield was constant up to 105R and diminished at 2×105R by 0.5%.
In comparison at the same lignin content, the pulping yield was constant up to 2×105R but decreased a little at 5×105R.
And then the difference between the pulping yield of hard wood in this paper and soft wood (Douglas-fir) in the recent two reports by Sarkanen, Nicholls and co-worker was discussed.
