降低水性油墨颗粒在纤维上吸附量的研究

Study on Reducing Adsorption and Deposition of Water-based Ink Particles onto the Fibers

废纸碎浆过程中由于水性油墨颗粒亲水性好、颗粒尺寸小等特点,很容易在与纤维分离后又重新吸附到纤维上,影响纸浆的光学性能。本研究针对水性油墨颗粒的特点,从温度、水性油墨颗粒浓度、油墨与纤维接触时间等方面利用模型对其吸附过程进行探究。结果表明,随着水性油墨颗粒浓度的升高,其在纤维上的吸附量先增加后趋于平缓,当水性油墨颗粒浓度为0. 4 g/L时,纤维对其吸附量接近最大值;温度的适当升高有利于降低水性油墨颗粒在纤维上的吸附;水性油墨颗粒在纤维上的吸附速度很快,5 min内接近最大吸附量。同时利用不同助剂改变水性油墨颗粒的胶体性质,聚合氯化铝(PAC)和阳离子聚丙烯酰胺(CPAM)均可以增加水性油墨颗粒的表面张力,当PAC和CPAM的浓度分别为11 mg/L和5 mg/L时,水性油墨颗粒的絮聚程度最大,在纤维上的吸附量最小,此时纸浆的白度最高、有效残余油墨浓度最低。

During the wastepaper recycling process, it s difficult to separate the water-based ink particles from the fibers due to its small size and hydrophilic property, leading to negative impact on the optical properties of the pulp. In this study, the influence of some parameters , such as temperature, particle consistency and contact time between the particles and the fibers on the adsorption process between water-based ink particles and softwood bleached pulp fibers were studied. The results showed that with the increase of water-based ink particle consistency, its adsorption amount onto fibers increased first then leveled off. When the consistency of water-based ink particles was 0.4 g/L, the adsorption amount was close to the maximum. Increasing the temperature appropriately could reduce the deposition of ink particles on fibers. The adsorption process proceeded very fast which almost reached to the maximum in 5 min. The properties of water-based ink particles could be changed by using different chemical additives. Both PAC and CPAM could increase the surface tension of ink particles. When the concentration of PAC and CPAM were 11 mg/L and 5 mg/L respectively, water-based ink particles had the highest flocculation degree, the recycled fibers had lowest ERIC and highest brightness which thanks to the least ink particles adsorption on the fibers.