颤杨机械浆和高得率浆的回用性能

THE RECYCLING BEHAVIOR OF MECHANICAL AND HIGH YIELD PULP OF ASPEN (Populus tremloides)

研究了颤杨机械浆和高得率浆在回用过程中性质的变化，并对照研究了黑云杉热磨机械浆的回用性能。结果表明，纸浆性质最明显的变化，发生在第一次回用后。用于研究的所有浆的保水值下降、游离度增加，并伴随着结合能力的降低，而纤维本身的强度并没有明显变化。云杉TMP对回用的反应与颤杨TMP不同；经磺化处理的颤杨CMP与未磺化的颤杨TMP也有区别。显然，机械浆和高得率浆的回用性能与树种和制浆条件有关。

Changes in pulp characteristics of aspen (Populus tremloides) mechanical and high yield pulps during recycling have been studied and compared with spruce thermomechanical pulp. The results obtained indicated that the most obvious change in fiber properties occurs during the first recycle. The increase in pulp freeness was always related to the loss in water retention value and was accompanied by a drop in fiber bonding capacity,but there was no significant change in fiber strength during recycling.Softwood mechanical pulp behaved differently from those of hardwood during recycling. Sulphite treated aspen pulps showed different recycling effects when compared with those untreated and the effect extent was found to be associated with sulphonate content. Pulps having higher sulphonate content showed greater changes than those having lower sulphonate content. It is evident that the recycling behavior of mechanical and high yield pulps is related to wood species as well as pulping conditions.