It will be covered in this latter part of the report, why has the paper from hardwood pulp become the main stream of the fine paper production.
In April in 1952, the paper from the hardwood bleached sulfate pulp without any softwood pulp was produced for the first time in the world at Yufutsu mill in Hokkaido, overcoming lots of conventional beliefs. It had been thought for long time that the paper should be made from softwood pulp. But Mr. Mizuno and his partner Mr. Shimura believed to be able to make the paper from hardwood sulfate pulp excellent in its characteristics, in respects of those other than strength, if prepared properly in preparation stage of the pulp. As well known, in view of composition of the wood, the hardwood contains much hemicellulose which will behave as binder of the interfiber bonding that contributes to strength of the paper, and if cooked in sulfate process, much more hemicelluloses would remain in the pulp than cooked in sulfite process. In other words, the hardwood is able to put forth his value by the combination with the sulfate process. So, the paper from hardwood showed the strength equal to the paper from softwood sulfite pulp, in spite of its short fiber length. In addition, as expected by Mr. Shimura, shortness of the fiber length itself has brought to the paper many excellent characteristics, for instance sheet formation, bulkiness, stiffness, opacity and so on. Therefore, the paper from hardwood has earned high reputation in the market for usage of printing, wrapping and others. It was not long before this method started to be adopted actively in Japan, followed by the rest of the world. In addition, generally speaking, hardwood grows much earlier compared with softwood. Therefore, many large paper making companies are developing the afforestation estate aiming for self-sufficiency of the raw materials of the paper. It might be said that pulp and paper industry is on its way to sustainable ecological model attached with the progress of the biotechnology together.
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