Non-wood Fibers Research Articles

Production and characterization of pulp and paper from flax straw

Flax (Linum usitatissimum) is a bast fiber plant known for its long fibers, making it an excellent source of pulp for paper production. In Ethiopia, flax is primarily cultivated for oil, with the residual straw utilized for papermaking. This study focuses on pulping flax straw using the Kraft process and investigates its chemical composition, proximate analysis, and morphological properties. The proximate analysis revealed an ash content of 4.13% and moisture content of 11%. Chemical composition analysis showed cellulose at 51.34%, hemicellulose at 25.20%, lignin at 14.12%, ash at 4.13%, and extractives at 5.21%. The morphological properties included a fiber length of 1.41 mm, diameter of 16.78 μm, lumen width of 9.45 μm, and cell wall thickness of 3.77 μm. Flax straw exhibited an acceptable Runkel ratio (0.8) and flexibility coefficient (56.32), placing it within the range of non-wood fibers. SEM analysis of the pulp’s morphology was conducted to assess fiber structure, including the presence of cracks. Pulp quality and length are directly linked to paper strength. Various pulping conditions were studied using a full-factorial design, with optimum conditions being 10% alkaline, 131.74°C, and 120 min of cooking time, yielding a pulp with a Kappa number of 10.45 and a yield of 40.56%. The resulting paper demonstrated standard tensile, tearing, and burst strengths, indicating that flax straw is a promising raw material for paper production.

Cellulose fiber drainage improvement via citric acid crosslinking

Wheat straw, as a non-wood fiber waste, is available worldwide and can be used in cellulosic matric production, promoting the application of sustainable materials. However, poor fiber properties and water drainage are the primary obstacles to its utilization. In this study, wheat straw pulp fibers were chemically crosslinked by citric acid (CA) in an environmentally friendly process. X-ray photoelectron spectroscopy and Fourier transform infrared spectra confirmed that the chemical treatment introduced carboxylic groups to cellulose fibers. Meanwhile, X-ray diffraction patterns showed that the crystallinity of cellulose was reduced. The average fiber length and water retention value of the pulp decreased with increasing CA dosage under the conditions of 3 mL/g CA4 (4 wt% CA), and the drainage performance of the cellulose pulp improved by 21 %. Also, the crosslinking of fibers contributed to the mechanical properties of the cellulosic matrix, increasing the dry and wet strength by 21 % and 282 %, respectively. These results demonstrated that citric acid could be a sustainable method for improving the properties of wheat straw fibers, thereby promoting its application in fabricating sustainable materials.

Evaluating chemi-mechanical pulping processes of agricultural residues: High-yield pulps from wheat straw for fiber-based bioproducts

This work evaluates the feasibility of APMP (alkaline peroxide mechanical pulping) and CTMP (chemi-thermomechanical pulping) of wheat straw as small-scale, low-capital expenditure pulping process to produce high-yield pulps for fiber-based bioproducts. APMP and CTMP wheat straw pulps were characterized in terms of pulping yield, freeness, ISO brightness, and fiber morphology. Additionally, both pulps were evaluated for tissue paper applications and benchmarked against BEK (bleached eucalyptus kraft) market pulp. APMP wheat straw pulps presented higher yield (75.2 – 79.8 %) compared to CTMP (69.1 – 80.6 %), depending on cooking chemicals and chemical charge during the chemical impregnation stage. The final brightness of APMP pulps varied from 36.4 % to 37.8 % ISO when sodium hydroxide and hydrogen peroxide were used as pulping agents without additional chemical additives. However, the brightness of APMP pulps can be increased up to 49.7 % ISO by using additional chemical additives such as EDTA (chelating agent), sodium silicate (peroxide stabilizer), or by employing a multi-stage chemical impregnation strategy. Both pulps produced fibers with similar morphological properties. A comparison of tissue-making properties showed that APMP pulps produced bulkier handsheets with higher water absorption capacity and better softness than CTMP pulps. However, CTMP pulps exhibited a higher tensile index than APMP pulps for a given pulp freeness. The results indicate that non-wood fibers, such as those derived from wheat straw, could be a promising alternative for use in fiber-based bioproducts such as hygiene tissue.

Physical and mechanical properties enhancement of beaten oil palm trunk pulp and paper by optimizing starch addition: Towards sustainable packaging solutions

Paper is a commonly utilized material in various aspects of daily life. However, the pulp and paper industry face environmental challenges related to pollution and deforestation. The utilization of non-wood fibres, such as agricultural waste of oil palm (Elaeis guineensis Jacq.) from oil palm trunk (OPT), may offer sustainable alternatives to wood-based pulp. However, the mechanical properties of OPT paper in this study need improvement to compete with wood-based paper. Incorporating starch as an additive can enhance the mechanical and physical properties of OPT paper. This study aimed to develop and characterize the unbleached OPT paper prepared via kraft and soda pulping methods and beating treatment. The mechanical properties are enhanced by adding starch at 5,10,15, and 20 %. Findings exhibited that the addition of starch increased the tensile strength of OPT papers but decreased tear resistance. Hence, the papers have a high potential to be applied as non-woody pulp source-sustainable alternative raw materials for packaging.

Wheat straw as base paper for barrier coating

A smooth and dense surface of the base paper is advantageous when the goal is to apply a liquid coating as a barrier layer. For such a base paper, non-wood fibers derived from wheat straw could be an alternative to wood fibers. In this research paper, wheat straw pulp was refined with different beating levels (up to 600 revolutions) followed by different calendering pressure loads (up to 50 N/mm) to test its influence on mechanical and surface properties. Alkyl ketene dimer (AKD) was used as sizing agent with concentrations up to 0.2 wt% followed by a mineral-based precoating to test its influence on the smoothness. Eucalyptus pulp was chosen as a benchmark. After beating, the initial Schopper-Riegler degrees of 28 °SR increased to 56 °SR. Beating also increased the tensile index from 24 to 49 Nm/g, the burst index from 1.2 to 2.8 kPa·m²/g, and the tear index decreased from 3.3 to 2.8 mN·m2/g. Calendering reduced the initial roughness of 370 mL/min to 30 mL/min. When precoated and calendered again, the value was lowered to 15 mL/min. In summary, wheat straw paper is a relevant alternative to wood-derived base paper to produce barrier papers. Compared to eucalyptus, wheat straw paper showed better smoothness and much lower air permeability indicating excellent suitability for barrier coating.

Preparation of Filter Paper from Bamboo and Investigating the Effect of Additives.

As air pollution escalates, the need for air filters increases. It is better that the filters used be based on natural fibers, such as non-wood fibers, which cause low damage to the environment. However, the short fiber lengths, low apparent densities, and high volumes of non-wood materials can make it challenging to prepare filter paper with the required mechanical and physical properties. In that context, this study focused on utilizing bamboo fibers to fabricate filter paper by employing the anthraquinone soda pulping method. The pulp underwent bleaching and oxidation processes, with the incorporation of cationic starch (CS) and polyvinyl alcohol (PVA) to enhance resistance properties, resulting in the creation of handmade filter papers. The findings revealed that the tear, burst, and tensile strength of filter paper increased with the oxidation and addition of CS and PVA. Air permeability increased with addition of PVA and combination of CS and PVA. FTIR demonstrated the conversion of hydroxyl groups in cellulose chains to carboxyl groups due to oxidation. SEM images illustrated alterations in the fiber structure post-oxidation treatment, with CS reducing pores while PVA and the CS-PVA combination enlarged pore size and enhanced porosity. The BET surface area surface area expanded with oxidation and the addition of the CS-PVA blend, indicating heightened filter paper porosity. Notably, the combined inclusion of CS and PVA not only augmented mechanical strength but also increased porosity while maintaining pore size.

Insights into lignocellulosic fiber feedstock and its impact on pulp and paper manufacturing: A comprehensive review

Concerns about the depletion of wood resources and the environmental impact of increasing demand for paper goods have led to the quest for alternate sources of fiber for pulp and paper manufacture. Non-wood fibers, such as agricultural residues, are seen as a sustainable and renewable source of fiber. However, due to changes in chemical composition, unpredictability, and processing methods, their utilization offers obstacles. Nonetheless, ongoing research in non-wood fiber pulping drives the development of new methods and technologies to enhance non-wood fibers' processability. Kraft pulping, known for efficacy and adaptability. This review provides comprehensive insights into the utilization of lignocellulosic non-wood fibers as sustainable alternatives to wood in pulp and paper manufacturing, backed by recent research. It explores the feasibility of non-wood fiber utilization and assesses various pulping processes' impacts on their properties. Notably, innovative pulping methodologies have emerged, addressing conventional approach shortcomings. Further research should focus on refining innovative pulping techniques and exploring alternative compounds to replace conventional chemicals, reducing ecological footprints. Efforts are needed to enhance non-wood fibers' processability through technology development. Collaboration among researchers, industry, and policymakers is vital to drive advancements and facilitate widespread non-wood fiber adoption. Exploring non-wood fiber applications beyond pulp and paper manufacturing could diversify fiber supply chains sustainably. In summary, the future of non-wood fibers in the pulp and paper industry is promising, with ongoing research and innovation expected to unlock their full potential, driving positive environmental and economic outcomes.

Life cycle carbon analysis of packaging products containing purposely grown nonwood fibers: A case study on the use of switchgrass pulp for linerboard and corrugating medium

Sustainability is driving innovation in the pulp and paper industry to produce goods with lower carbon footprints. Although most of the efforts are currently focused on increasing energy efficiency or switching to renewable fuels, the attention toward alternative feedstocks has increased in recent years. Claims of nonwood fibers requiring lower use of chemicals and energy than wood fibers, along with negative consumer perceptions of tree felling, are helping purposely grown nonwoods to gain market share. The potential nonwood fiber environmental superiority over virgin or recycled wood fibers remains controversial and is often driven more by emotion and public perception rather than facts. This paper estimates the carbon footprint of corrugating medium and linerboard containing switchgrass pulp compared to analogous wood-based materials. The study includes a life cycle carbon analysis spanning from cradle to gate, which comprises stages for fiber production, pulping, papermaking, and corresponding transportation. Carbon footprints for virgin linerboard, recycled linerboard, virgin medium, and recycled medium were estimated at around 510, 620, 460, and 670 kg carbon dioxide equivalent per metric ton (kg CO2eq/t), respectively. Replacing 30% of the virgin or recycled material with switchgrass pulp translated into carbon footprint increases of around 60%, 45%, 62%, and 38%, respectively. Thus, for the proposed case study, the results suggest that switchgrass-based medium and linerboard can present a higher carbon footprint than products made from virgin and recycled wood fibers. The main driver is the production of nonwood mechanical pulp. This study was designed to mitigate part of the uncertainty around the environmental sustainability of medium and linerboard made from the selected purposely grown nonwood fibers.

Understanding Binding of Quaternary Ammonium Compounds with Cellulose-Based Fibers and Wipes for Renewable and Sustainable Hygiene Options

Cellulose-based fibers are desirable materials for nonwoven wipes for their good absorbency, strength, cleaning, and biodegradable properties. However, quaternary ammonium compounds (QACs), being cationic in nature, show electrostatic interactions with anionic cellulosic fibers, reducing the available QACs to efficiently clean surfaces. This research presents sustainable alternative fibers that show better controlled exhaustion than commercial wipes and textile fibers. Textile and lignocellulosic fibers were prepared, soaked in QAC, and a UV–vis spectrophotometer was used to measure their exhaustion percentages. Factors such as immersion time and concentration of the disinfectant were also investigated, which affect the rate of exhaustion of the disinfectant from the fibers. A higher immersion time resulted in better exhaustion, whereas the total exhaustion decreased with an increase in the initial concentration of the disinfectant. The exhaustion of benzalkonium chloride (BAC) from the commercial wipes was also investigated at different immersion times and BAC concentrations. It was found that the wood and non-wood fibers showed more controlled exhaustion than the textile fibers and commercial wipes, and could be considered an alternative option for renewable and sustainable wipes and hygiene products.

Fundamental investigation of micro-nano cellulose and lignin interaction for transparent paper: Experiment and electrostatic potential calculation

Plastic has significant negative consequences for the environment and human health, demanding greener alternatives. Lignocellulose is a sustainable biomass material, and its paper has been considered as a potential material to replace plastics. Micro-nano lignocellulose, derived from natural plants, possesses a small size and abundant hydrogen bonding capacity. However, there is no clear explanation for the interactions between lignin and micro-nano cellulose, and little understanding of how the interaction can affect the papers' structure and optical properties. Electrostatic potential calculation is a reliable tool to explain non-covalent interactions, and can explore the binding between lignin and micro-nano cellulose. In this paper, kenaf – a non-wood fiber raw material – was employed to prepare micro-nano lignocellulose. The resulting slurry facilitated the production of transparent paper via a simple casting method. The prepared transparent micro-nano paper exhibited high transparency (~90 %), UVA resistance (~80 %), and hydrophobicity (~114°). More importantly, the electrostatic potential calculation demonstrates the inherent relationship between structure and performance, providing practical knowledge for constructing film materials.

Utilization of Non-Wood Fibers as Raw Materials for Pulp and Paper Production in Pakistan: A Review

Utilization of Non-Wood Fibers as Raw Materials for Pulp and Paper Production in Pakistan: A Review

Recovery of Pulp from Oil Palm Empty Fruit Bunch and Used Paper for Sustainable Paper Production

Agricultural waste residue such as empty fruit bunch (EFB) has great potential as an alternative feedstock in pulp and paper industry. This study provides insights into the use of EFB as an alternative non-wood fibre resource for pulping and papermaking. EFB was mixed with used paper (UP) according to the ratio of 100:0, 75:25, 50:50, 25:75 on dry basis. The hemi-cellulose and lignin contents in EFB was removed by soda-pulping using 15% w/v sodium hydroxide for 30 minutes at 100°C. Chemical analyses were performed to determine the ash content, lignin content, and the cellulose content (Rowel method). Physical and mechanical properties of the EFB/UP paper were characterised according to the TAPPI Standards including grammage, porosity, moisture content and tensile strength. The average fibre length of all EFB/UP papers showed different fibre length ranging from 1.0 to 1.2 mm. EFB25 (25% EFB) was found to have the least moisture content of 7.28% meanwhile EFB100 had the least ash content of 2.28% and the highest cellulose and lignin content of 45.22% and 26.5%, respectively. EFB25 demonstrated the highest tensile index of 2.01 Nm/g. There are no major colour changes and no trace of fungal growth on the surface of all paper samples after 4 weeks of storage without temperature and humidity control. It was found that paper with EFB25 displayed good physical appearance with grammage of 59.8 g/m2 that is almost comparable to commercialised paper of 70 g/m2 and suitable for writing.

An overview on non-wood fiber characteristics for paper production: Sustainable management approach

The amount of paper and paperboard a country uses are a reliable barometer of its development. Having access to them is essential to our daily life. The Indian paper industry faces a number of challenges, one of which is a scarcity of high-quality raw materials. Agricultural waste products have become essential alternative sources of supply as a result of an increase in the need for fibrous raw materials, a global lack of trees, and a growing awareness of sustainability. When compared to the manufacturing of pulp and paper from wood sources, the use of non-wood sources (including bagasse, maize stalks, cotton stalks and rice straws) offers a number of advantages. These benefits include superior quality of the bleached pulp and excellent sources for specialty papers. Paper manufacture is more ecologically friendly and sustainable when non-wood fibers are processed since non-wood pulping technologies use less energy than wood-based pulping processes. Furthermore, the financial advantages include cost savings, market differentiation, enhanced sustainability, and access to government subsidies. By investing in non-wood fibers to satisfy rising customer demand for environmentally friendly goods, paper manufacturers may position themselves for long-term prosperity and environmental responsibility. The non-wood fibers are cellular and have a complex cell wall structure. A thorough understanding of their properties is essential for effective use. Therefore, the objective of the present review is to explore the wide variation between critical characteristics (morphological, chemical, and mechanical) and the most appropriate pulping and bleaching processes for commonly used agricultural residues (Rice straw, Bagasse, Wheat straw and Bamboo) in the Indian pulp and paper industry for the production of paper, board, and packaging.

Coupling laccase/PHB and Ca2+ treatment enable high-strength straw chemi-mechanical pulp

Non-wood fibers (e.g., straw) show a large volume in China, which effectively offsets the shortage issue of the forest resource, especially as raw material in the pulping and papermaking industry. The chemi-mechanical pulp (CMP) from the straw is significantly developed due to the advantages of high pulp yield, mechanical strength, and low cost. While the large-amount lignin exposed the pulp fiber surface of straw CMP negatively affects the bonding between its fibers, thus restricting the further improvement of its physical properties. Herein, we developed an environmentally friendly strategy of coupling the laccase/PHB and Ca2+ treatments to modify the chemical and structural properties of fibers toward the high-strength straw CMP. The laccase/PHB treatment removes the lignin of the straw CMP with a Kappa number decrease from 108.28 of the original sample to 75.65 with an 8 u/g dosage of laccase at a 3% PHB system. The removal of lignin with a stiff property also modifies the fiber morphologies of straw CMP, including increasing the measured fiber curl index from 8.0% to 8.5%, and the kink angle from 129° to 137°. Simultaneously, the introduced Ca2+ triggers the strong bonding with the anionic groups of straw CMP fibers, which creates enough, multiple bonds in this fiber system. The coupling laccase/PHB and Ca2+ treatments boost the mechanical strength of the straw CMP, more specifically, the tearing index, tensile index, and bursting index increase from 3.51 mN•m2/g, 20.01 N•m/g, and 1.57 KPa•m2/g of original pulp to 4.56 mN•m2/g, 29.80 N•m/g, and 2.26 KPa•m2/g, respectively. This integrated strategy of laccase/PHB and Ca2+ treatment provides a valuable guideline for improving the strength performance of plant fibers, beyond the straw CMP.

Tensile strength estimation of paper sheets made from recycled wood and non-wood fibers using machine learning

Tensile strength estimation of paper sheets made from recycled wood and non-wood fibers using machine learning

Utilization of Laboratory Papers with Non-Wood Fibres as Printing Substrates Observed Through the Maximum Ink Penetration Depth

The use of non-wood fibres for paper production could be one of the most environmentally friendly and economical alternatives. Reducing the consumption of wood pulp in paper and cardboard production by replacing wood pulp with alternative plant biomass could be a viable solution, as the amount of non-wood fibres in biomass is far from being exhausted. In this study, straw from the most commonly grown agricultural crops in Croatia was used as a source of non-wood fibres. Agricultural residues from wheat, barley and triticale were selected as a substitute for wood fibres for the production of laboratory papers with straw fibres. Under laboratory conditions, straw pulp was mixed with recycled wood pulp in a ratio of 30:70 to produce paper sheets that can be printed with different printing techniques. Regardless of the printing technique used, it is desirable that the prints contain a high-quality reproduction of the image and text on the surface of the paper and that the ink does not penetrate completely through the substrate. In this context, this study observed the use of laboratory-made papers with non-wood fibres as the printing substrate by analysing the maximum depth of ink penetration into the printing substrate obtained with two printing techniques - a modern one (digital UV inkjet) and a very high quality conventional one (gravure). It was found that the gravure printing favoured a greater penetration of the UV ink into the substrate with the addition of straw pulp compared to the digital printing technique. However, this is a consequence of the printing technique, as similar ink penetration was also observed on the laboratory substrate made only from recycled fibres. Compared to commercial papers, the ink penetration is slightly higher into the laboratory made printing substrates. It is interesting to note that the printing substrate with the addition of 30% triticale pulp has the lowest ink penetration, especially in multicolour prints produced with the digital UV inkjet printing technique.

Effective Tensile Strength Estimation of Natural Fibers through Micromechanical Models: The Case of Henequen Fiber Reinforced-PP Composites.

The performance of henequen fibers and polypropylene composites obtained by injection molding with and without coupling agent was evaluated. Henequen fibers are natural non-wood fibers mainly used in textile sector or in thermosetting matrix composites. In this work, henequen fibers have been used as a possible substitute reinforcement material for sized glass fibers. The surface charge density of the materials used was evaluated, as well as the morphology of the fibers inside the material. A significant reduction in the length of the fibers was observed as a consequence of the processing. The use of a 4% coupling agent based on fiber content was found to be effective in achieving significant improvements in the tensile strength of the composites in the reinforcement range studied. The influence of the aspect ratio on the coupling factor was determined, as well as the evaluation of the interface quality. The results obtained demonstrate the great potential of henequen fibers as reinforcement of composite materials, giving rise to strong interfaces with coupling. Finally, the comparison of henequen fiber composites with sized glass fiber composites showed that it is possible to substitute polypropylene composites with 20 wt.% glass fiber for 50 wt.% henequen fibers.

POTENSI AMPAS KELAPA (Cocos nucifera L.) SEBAGAI ALTERNATIF BAHAN PEMBUATAN KERTAS KOMPOSIT

Coconut dregs is a waste that has non-wood fiber thus it is potential as a material for making composite paper. The use of coconut dregs in this study aims to determine its potential as a raw material for making composite paper through tensile resistance and tear resistance.
 The making of composite paper in this study was carried out by combining coconut pulp and used HVS paper pulp. The design used was a completely randomized design (CRD) with 3 replications consisting of 3 treatments and a control. The data obtained were analyzed using the Anova test and the DMRT test with a level of 5%..
 The highest paper tensile resistance test results were obtained by P1 which was 0.26 kN / m smaller than 1.26 kN / m (P0 as a control), as well as the highest paper tear resistance test results obtained by P2 at 340 mN smaller than 666 , 4 mN (P0 as control). Based on the data obtained, the addition of coconut dregs or not in making composite paper shows a potential that does not have a significant effect. This research has the potential to be developed for better paper quality.

Study on the application of Zizania latifolia straw in papermaking

Zizania latifolia is a vegetable that is native to China. Z. latifolia has a long history and a huge yield. Usually, the biological mass of leaves and sheaths of Z. latifolia account for 50% to 70% of the total mass of the plants, so there is a lot of residual Z. latifolia straw after cultivation. This causes pollution to the local environment and rivers. At the same time, non-wood fiber materials have always been one of the raw materials used in the paper industry. The purpose of this study was to turn the large-scale abandoned Z. latifolia straw into a valuable resource and bring a new treatment idea of Z. latifolia straw papermaking. By comparing the Z. latifolia paper with conventional old corrugated container paper, this study introduced a new idea for solving the treatment of Z. latifolia straw abandoned in Jinyun, China.

Effects of Non-Wood Fibres in Printed Paper Substrate on Barrier and Migration Properties

Nowadays, there is a strong initiative to use recycled or biodegradable materials in all aspects of production including the graphic industry. In this study, paper was used as a material fulfilling the two of mentioned properties. Under laboratory conditions, papers were made of 70% pulp from recycled wood fibres with an addition of 30% straw pulp (wheat, barley or triticale). Considering the importance of the possibility of printing such media based on their end use, the influence of fibre type on vapour barrier properties was studied and overall migration to hydrophilic and fatty food simulants was measured. Analyses were performed on digital, flexographic, and offset prints obtained by printing laboratory papers with UV-curable black ink. It was found that prints produced using the offset technique, in which the ink remains on the surface of the paper, had lower overall levels of migration compared to other printing techniques. The paper produced appears to have the potential to be used as a secondary food packaging material.