印刷后超过 6个月的陈旧新闻纸 (缩写 ONP)，通常被认为难于采用常规方法进行脱墨，为了脱除此类过度老化的 ONP，国外研究人员利用水皂类及不溶混有机溶剂的组合物。在规定的加工条件下，研究人员无需进一步漂白，就取得了最大白度，接近于原纸 (版边空白原料 )的纤维素浆料。 Outdated newsprint (abbreviated ONP), which has been printed for more than six months, is generally considered difficult to deink in the conventional manner. To remove such over-aged ONP, foreign researchers make use of a combination of water soap and an immiscible organic solvent . Under the specified processing conditions, the researchers achieved the maximum whiteness without further bleaching, close to the cellulosic pulp of the base paper (margin blank).