Abstract The hypothesis is that it should be possible to modify papermaking conditions in line with the softening properties of high yield pulp fibres and achieve similar strength properties to conventional chemical pulp based paper. We therefore investigated the rheological and physical properties of high yield pulp based papers during hot-pressing. Our results confirm that increased temperature combined with sufficient pressure enables permanent densification by softening of lignin, producing very high tensile strength. This treatment also significantly improved the wet tensile strength in comparison to bleached kraft pulp without using wet strength agents. The high yield pulps used here were spruce based thermomechanical pulp, chemi-thermomechanical pulp, and high temperature chemi-thermomechanical pulp, and birch-aspen based neutral sulphite semi chemical pulp, with spruce-pine based bleached kraft pulp as reference. Rapid Köhten sheets of 150 g / m 2 150\hspace{0.1667em}\text{g}/{\text{m}^{2}} and 50 % dryness were hot-pressed in a cylinder-press at 20–200 °C, 7 MPa, and 1 m/min. The mechanical properties showed great improvements in these high yield pulp papers, with tensile index increased to 75 kNm/kg and compression strength index to 45 kNm/kg; levels close to and better than bleached kraft. Wet strength increased to 16 Nm/g compared to 5 Nm/g for bleached kraft.

中文翻译：

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通过热压由高产量纸浆制成的高强度纸

摘要 假设应该可以根据高产纸浆纤维的软化特性修改造纸条件，并实现与传统化学纸浆纸相似的强度特性。因此，我们研究了热压过程中高产量纸浆纸的流变学和物理特性。我们的结果证实，升高的温度与足够的压力相结合，可以通过软化木质素实现永久致密化，从而产生非常高的拉伸强度。与不使用湿强度剂的漂白牛皮纸浆相比，这种处理还显着提高了湿拉伸强度。这里使用的高得率纸浆是基于云杉的热机械纸浆、化学热机械纸浆和高温化学热机械纸浆，和桦木-白杨基中性亚硫酸盐半化学浆，以云杉-松基漂白牛皮纸浆为参考。150 g / m 2 150\hspace{0.1667em}\text{g}/{\text{m}^{2}} 和 50% 干度的快速 Köhten 片材在滚筒压机中以 20-200 的温度热压°C、7 MPa 和 1 m/min。这些高得率浆纸的力学性能有了很大的提高，拉伸指数提高到75 kNm/kg，抗压强度指数提高到45 kNm/kg；水平接近并优于漂白牛皮纸。与漂白牛皮纸的 5 Nm/g 相比，湿强度增加到 16 Nm/g。这些高得率浆纸的力学性能有了很大的提高，拉伸指数提高到75 kNm/kg，抗压强度指数提高到45 kNm/kg；水平接近并优于漂白牛皮纸。与漂白牛皮纸的 5 Nm/g 相比，湿强度增加到 16 Nm/g。这些高得率浆纸的力学性能有了很大的提高，拉伸指数提高到75 kNm/kg，抗压强度指数提高到45 kNm/kg；水平接近并优于漂白牛皮纸。与漂白牛皮纸的 5 Nm/g 相比，湿强度增加到 16 Nm/g。