Old Newspaper Research Articles

Dry-Process Hardboards from Recycled Newsprint Paper Fibers

AbstractDry-process hardboard represents a favorable option for recycling old newspaper fibers. However, dry-process boards tend to be less dimensionally stable than boards processed by other methods. Our objective was to determine the effects of various wood fiber (WF) to old newspaper (ONP) ratios (100:0, 50:50, and 0:100 WF/ONP) on the mechanical strength and water resistance of dry-process hardboards made from these fibers. Untreated and acetylated hardboards were made with 3 or 7 percent resin and 0.5 percent wax. Boards were tested for static bending and tensile strength properties and water resistance. As expected, increasing the resin level from 3 to 7 percent generally improved all measured properties. Acetylation substantially improved the water resistance of all boards; increasing the amount of ONP caused a corresponding deterioration in both mechanical properties and water resistance.

最近の新聞古紙の脱墨性に及ぼす経時変化の影響 ニーダー導入による脱墨性の変化

Nowaday, we are required of the reuse of waste paper for refuse disposal and rainforest problem.As a method of further use of old newspaper (ONP), we are considering that DIP over 70% brightness will be available for middle grade paper instead of BKP, GP, TMP, CTMP. Therfore, We are making research on the deinking-bleaching technology for higher brightness to enlarge the use of old newspaper.On the investigating of high brightness DIP, we have researched the effect of aging period (stock period) on deinking property and kneader using three major newspapers (A, B, C company).The offset press ONP of B, C company appeared the deterioration of deinking property by aging. But surprisingly A company ONP did not appear such phenomenon. Letter press ONP did not show such phenomenon.Use of kneader could prevent considerably such deterioration of deinking property by aging of offset press ONP. But the brightness of letter press ONP which has easily deinking property lowered greatly by increasing of super fine particles size of ink.The offset press ONP of A copmpany was deinked well with and without kneader. So, that type of printing method will be faborable if the deinking property is considered.

進化するＤＩＰ技術 ＤＩＰシステム構築への提案

In the old newspaper (ONP) high consistency DIP system, there are three key factors to determine the pulp brightness, that is;-Bleaching effect-Separation of the ink particles from the fiber-Removal of the separated inkIt was proven in our DIP trial that removal of fines such as the separated ink, ash, fine fibers, etc. before high consistency treatment stage largely affects to these three factors.The main reason for such effect is considered that materials wasting the hydrogen peroxide and alkaline agent was taken out of system, that is, the ink vehicle itself, heavy metals that will be included in the fine ink vehicles, and fine fibers.