Abstract
Below mentioned changes were observed in the quality of N-BKP and L-BKP after stored 20 days under the following conditions.
(a) Applying of ultraviolet rays for 3 hours per day.
(b) Applying visible ray.
(c) In dark box.
Table 1 and table 2 are the results of the observation after 10 days and 20 days treatments respectively, the summary is as following;-
Bursting strength; decreased with the aging.
Tensile strength; decreased with the aging.
Brightness; almost unchanged.
α-cellulose; almost unchanged.
β-cellulose; slightly increased.
1% NaOH sol, solubility; slightly increased.
10% NaOH sol, solubility; slightly increased.
Carboxyl group; distinctly increased.
It seems that brightness value decreased due to the impurity or imperfect washing.
In respect to paper treatment :
Table 5 and 6. show the data of kraft paper exposed 20 days in the open air. According to these tables undermentioned phenomena were observed in the case of air aging;-
(1) Bursting strength decreased about 30%;
(2) Both 1% and 10% NaOH sol, solubilities increased by more than 250% of initial value.
