Effect of Ozone Treatment on the Properties of Oil Palm Empty Fruit Bunch Sulfonated Chemi-Mechanical Pulp

Oil palm empty fruit bunch (EFB) as an abundant waste material can be utilized for pulp production to alleviate the shortage of raw materials in the paper industry. Sulfonated chemi-mechanical pulp (SCMP) has great potential in paper making industry. However, its poor performance due to the high surface lignin content limits its application. In this study, we used EFB as raw material to produce SCMP and systematically studied the effect of ozone treatment on pulp properties. Results show that the surface structure and morphology of fibers exhibited distinct differences under different ozone dosage treatments. Compared to the control, the content of surface lignin of pulps was reduced by 2.56%, 4.64%, 13.24% and 25.24% when ozone consumption was 1, 3, 5 and 7 wt%, respectively. Meanwhile, the treated pulp had a lower drainability at the same refining energy level. Moreover, the physical and optical properties of handsheets were improved significantly after ozone treatment. Ozone treatment is a very efficient way to improve the performance of SCMP. Additionally, this method avoids complicated processes and chemical consumption. Therefore, as an effective, environmentally friendly and low-cost treatment method, ozone treatment can improve the performance of EFB SCMP and thus provide a high-quality pulp resource.

Fibre development in an intensified mechanical pulping process

Mechanical pulp for printing paper can be produced with a process that involve much less equipment and that require much lower specific energy compared to conventional processes. Even though common evaluation methods, e.g. handsheet testing, have shown that the pulp quality is similar for the simplified and the conventional processes, it is not known how fibre properties, at the microscopic level, is developed with the simplified process. In this mill scale study, the fibre properties attained with an “intensified” mechanical pulping process, consisting of single stage high consistency double disc refining followed by two stage low consistency refining and no reject treatment was investigated. The simplified process was compared to a process with a reject system. The simplified process rendered fibres with higher degree of fibrillation, higher share of axial splits, lower fibre wall thickness but slightly lower length than the conventional process. The fibrillar fines size distribution of the two processes was different. The conventional process generated more of small fibrillar fines which probably explains the higher tensile index at given density for that process. The results show that it is possible to simplify the production process for mechanical pulp and reduce the specific energy with over 700 kWh/adt.

The impact of molded pulp product process on the mechanical properties of molded Bleached Chemi-Thermo-Mechanical Pulp

This study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time, and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 30h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.

Effect of Pretreatments on the Enzymatic Hydrolysis of High-Yield Bamboo Chemo-Mechanical Pulp by Changing the Surface Lignin Content

Hydrogen peroxide chemo-mechanical pulp (APMP), sulfonated chemo-mechanical pulp (SCMP), and chemical thermomechanical pulp (CTMP) were used as raw materials to explore the effects of hydrogen peroxide (HP), Fenton pretreatment (FP), and ethanol pretreatment (EP) on the enzymatic hydrolysis of high-yield bamboo mechanical pulp (HBMP). The surface lignin distribution and contents of different HBMPs were determined using confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The correlation between the surface lignin and the enzymatic hydrolysis of HBMP was also investigated. The residue of enzymatic hydrolysis was used to adsorb methylene blue (MB). The results showed that the cracks and fine fibers on the surface of APMP, SCMP, and CTMP increased after FP, when compared to HP and EP. The total removal content of hemicellulose and lignin in SCMP after FP was higher than with HP and EP. Compared to SCMP, the crystallinity increased by 15.4%, and the surface lignin content of Fenton-pretreated SCMP decreased by 11.7%. The enzymatic hydrolysis efficiency of HBMP after FP was higher than with HP and EP. The highest enzymatic hydrolysis of Fenton-pretreated SCMP was 49.5%, which was higher than the enzymatic hydrolysis of Fenton-pretreated APMP and CTMP. The removal rate of MB reached 94.7% after the adsorption of the enzymatic hydrolysis residue of SCMP. This work provides an effective approach for a high value-added utilization of high-yield bamboo pulp.

Effects of lignin content and acid concentration on the preparation of lignin containing nanofibers from alkaline hydrogen peroxide mechanical pulp

The poplar alkaline hydrogen peroxide mechanical pulp (APMP) with the lignin content of 24.63 % was used as raw material, which with lignin content of 10.04 %, 6.33 %, 3.82 %, and 1.14 % were obtained by the acid sodium chlorite method for 1–4 hours respectively. Then, different lignin content APMP were micro-nano processing treated with acidolysis (6.5 M, 9.8 M) or ultra-granular grinding respectively. Afterwards, poplar bleached chemical pulp (BCP) was prepared micro-nano cellulose under the same conditions as the APMP. Then, compared the data of the particle size, specific surface area, fiber morphology and zeta potential of suspensions between micro-nano cellulose products. The results show that the presence of a small amount of lignin (1–4 %) in APMP does not affect the preparation of different scales nano cellulose under different acid concentration conditions. When the lignin content is reduced to below 2 %, the acidolysis is more uniform, stable, and well-dispersed compared to BCP products; when the APMP is processed by the ultra-granular grinding, the higher lignin content, the more obvious cutting effect in the fiber length direction. The characteristics and feasibility of the preparation of micro-nano cellulose by the acidolysis and ultra-granular grinding using APMP with varying degrees of delignification are compared.

Impact of stone ground ‘V-fines’ dispersion and compatibilization on polyethylene wood plastic composites

Recent studies have suggested that blocky mechanical pulp fines (CTMP fines) and fibrillar fines (SMC fines) have a negative impact on biocomposite modulus of rupture (MoR) in compression molded biocomposites. In addition, it was suggested that CTMP fines also have a negative impact on biocomposite modulus of elasticity (MoE). This study investigated whether these findings transfer to other types of cellulose fines material and injection molding. The effect of ‘V-fines’ addition to sawdust- and TMP-based biocomposites was analyzed, with respect to fines concentration, dispersing agent, and compatibilizers. The results indicated that the addition of ‘V-fines’ increased the stiffness (MoE) of all the analyzed compositions, while reducing the elongation at break. The addition of ‘V-fines’ reduced the tensile and flexural strength of TMP biocomposites, while it was largely unaffected for sawdust biocomposites. Flexural strength for neat ‘V-fines’ composites showed an increase that was proportional to the remaining pulp fibers composition. The addition of a dispersant agent to the ‘V-fines’ increased tensile strength, suggesting that an increased dispersion of the ‘V-fines’ can be achieved and is beneficial to the composite. The effects of the analyzed compatibilizer (polyethyleneoxide) was negligible, except for a small indication of increased MoE for fines / sawdust biocomposites.