Bleached Kraft paper pulp (KP) was hydrolyzed with powdered cellulase, and the changes of paper strength and some characteristics assumed to affect strength propertise were studied.
Both of tensile and tear strength considerably decreased with the time of cellulase treatment, while those in high-α sulfite pulp (SP) increased.
The changes of characteristics including cellulase treating yield, water retention value (WRV), fine content, specific volume of the web, pentosan content and number-average fiber length were studied to investigate their influence on the paper strength properties.
As a consequence, it was presumed that these differences in changes of strength properties and other characteristics between KP and high α-SP were caussed by the reasons as follows : (1) the changes in WRV and fine content of KP with cellulase treatment were little and the number-average fiber length was lowered, (2) the changes in WRV and fine content with cellulase treatment affect hydrogen bonding only a little, since KP has larger swellability and web had more amount of interfiber hydrogen bonds originally, and (3) the degree of entanglement of fibers and the single fiber strength properties were higher in the case of KP, so the lowering of fiber length affected tensile and tear strength more severely.
Thus, it was concluded that the differences in the changes of strength and other characteristics with cellulase treatment between KP and high α-SP depend mainly upon the swellablity of each fiber.

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Petroleum resin of which molecular weight is 750 and bromine value is 19.35 was ozonized. The reaction proceeds easily at low temperatures, and the ozonide groups introduced into the resin were about 4.5 times as many as the double bonds had been estimated as bromine value.
The petroleum resin molecule was partially collapsed with the ozonization, and the oxydation occured on the aromatic ring of the petroleum resin to give free radicals which can be used as sites for grafting reaction of acrylamide. The graft copymerization of acrylamide onto the petroleum resin was carried out in ethyl acetate solution at 60°C for three hours under nitrogen atmosphere.
The reaction products were quantitatively fractionated and each structure of the fraction was investigated by means of infra-red spectrophotometry.
It was suggested that a part of the radicals initiates the graft copolymerization, while another parts are decomposed to carbonyl and carboxyl groups. Homopolymerization of acrylamide was scarcely found to occur.
The yield of graft copolymer increased with the degree of ozonization of petroleum resin and the amount of monomer.
Within the present experimental conditions, the molecular weight of the graft copolymer was 500700, and about 1.5 times weight of acrylamide was grafted onto the petroleum resin.

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This study, based on pulping tests involving twenty highly diversified species of tropical hardwoods, was undertaken to determine the effects of morphological properties and chemical components of hardwoods on pulp properties.
The results from this study indicate that the pulp properties of these tropical hardwoods are related to the morphological and chemical characteristics of the wood. These relationships have been expressed by multiple regression equations (Table 6).
The following wood and fibre characteristics have been shown to be significant in their effects upon propertise : in pulp yield-holocellulose ; in Roe number - lignin ; in brightness (unbleached) - hexan soluble, lignin, fibre diameter, and l/D ; in sheet density - ash, lignin, and l/D ; in breaking length - hexan soluble, and specific gravity (wood); in burst factor - hexan soluble, and specific gravity (wood); in tear factor - fibre length ; in folding endurance - ash, and lumen width.
Most pulp properties, excepting folding endurance, should be possible to predict with a high degree of accuracy from a knowledge of the wood and fibre variables.

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