Improved Drainage of LNFC-reinforced Recycled Pulp and Mechanical Properties of End Papers by the Zeolite- Chitosan Microparticle Drainage Aid System

Good drainage of the pulp suspension is vitally important for stable papermaking. Although the addition of lignocellulosic nanofibers (LNFC) in pulp could highly reinforce the end paper sheets, the application of LNFC could diminished the pulp drainage. To solve this problem, the impact of the zeolite-chitosan and bentonite-chitosan microparticle drainage aid systems on the LNFC-reinforced recycled pulp was systematically investigated. Results indicated that the mentioned microparticle systems improved the drainage and retention especially in applying 1% chitosan with 0.3% zeolite. In mechanical properties, applying the microparticle systems, not only did not deteriorate these properties, but also improved most of them, especially in treatment containing zeolite-chitosan. It seems that the improved pulp drainage and the mechanical properties of the end papers was due to successful mission of microparticle system and synergistic interactions of pulp fibres, LNFC, chitosan, and zeolite, which could also lead to denser and more uniform structure of handsheets

Potential of GL as cationic polymer to control stickies of OCC pulp

Stickies is among the major challenges in paper recycling mills. This substance deposits on paper machine components and cause to break paper web as well as loss of end product quality. So, it is necessary to control the stickies and lessen its detrimental effects. It is known that cationic polymers as fixing agents can control the stickies efficiently. Therefore, the control of stickies of OCC pulp using a commercial cationic polymer called GL at 0.4, 0.8 and 1.2 percent based on oven dry weight of pulp at pH 4 and pH 5 were investigated. Macro- and microstickies, dissolved and colloid substances (DCS), turbidity, and drainage time were measured to evaluate GL efficiency and compared with control sample. The results indicated that GL dosing at 0.4 and 0.8 percent in pH 4 and 7 due to flocculation and fixing the stickies onto the fiber caused to decrease in macro stickies, microstickies and DCS while improved the drainage time. Although, no efficient performance was observed in controlling stickies at higher content of GL i.e. 1.2 percent. Generally, it is concluded that with consuming at desired pH and dosage content, GL can be used as efficient agent to control stickies in processing of OCC pulp

The Effect of External and Internal Application of Organosilicon Compounds on the Hydrophobicity of Recycled OCC Paper

There are various applications of organosilicon compounds in papermaking. Additionally, organosilicons have been applied to improve the water resistance of some lignocellulosic materials. The performance, however, of such compounds for the hydrophobation of paperboard is unclear. In this study, an organosilicon solution was internally and externally applied to old corrugated container (OCC) paperboard at ambient temperature. Examination of the infrared spectra of treated paperboard confirmed the presence of CH2 groups and hydrophobic organic chains of organosilicon in the treated paperboard. Both internal and external treatment of the paperboard helped its resistance to water, though external treatment was more successful in the late reduction of the contact angle of water droplets and also in reducing water uptake