制浆流程对杨木SCMP白度和物理强度的影响

Effect of Improved Process on the Brightness and Physical Properties of Poplar SCMP

研究了改进的SCMP流程对成浆白度和物理强度的影响。研究发现,磺化后磨浆浆料白度下降较严重;H2O2漂白后磨浆,前期白度提高,继续磨浆白度稍有下降,在一段磨浆前后进行H2O2漂白可减少磨浆对白度的不利影响。化学预处理可改善纸浆强度,以磺化+挤压+H2O2处理对木片的软化的效果最好,成浆的强度指标最高。相对于汽蒸处理,化学预处理对木片的软化可减少挤压对纤维造成的损伤,SCMP生产的挤压处理以木片磺化反应后进行较优。H2O2漂白中,NaOH对强度的提高起到决定作用。

The influences of improved SCMP process on the brightness and physical properties of the pulp from poplar were studied in this paper. The results showed that the brightness decreased greatly in refining with sulphonation pretreatment; the brightness increased firstly, then decreased slightly during refining when refining was carried out after bleaching with peroxide, so peroxide bleaching before or after the first refining stage could eliminate the negative influence of refining on the brightness development. Chemical pretreatment before refining could promote the physical properties of the pulp in refining. Treatment of sulphonation, compression and peroxide bleaching sequentially gave best softening to the chips and resulted in the best strength properties of the pulp. Softening effect on the chips of chemical pretreatment could decrease fiber failure resulte from compression; compression treatment of SCMP process was preferable after sulphonation treatment. Sodium hydroxide was crucial to boost the strength in peroxide bleaching of SCMP, while peroxide mainly upgraded the brightness with less effect on physical properties. Based on the measurements of improved SCMP, pulping energy and chemicals saving, pulp quality upgrading could be achieved by harmonizing the pulping process.