Papermaking Industry Research Articles

High-Value Utilization of Cellulose: Intriguing and Important Effects of Hydrogen Bonding Interactions─A Mini-Review.

Cellulose has been widely used in papermaking, textile, and chemical industries due to its diverse sources, environmental friendliness, and renewability. Recently, much more attention has been paid to converting cellulose into high-value-added products. Therefore, the extraction of nanocellulose, the dissolution of cellulose, and their applications are some of the most important research topics currently. However, cellulose's dense hydrogen bond network poses challenges for efficient extraction and dissolution, limiting its potential for functional material development. This review discusses the mechanisms of hydrogen bond disruption and weak interactions during nanocellulose extraction and cellulose dissolution. Key challenges and future research directions are highlighted, emphasizing developing efficient, ecofriendly, and cost-effective methods. Additionally, this review provides theoretical insights for constructing high-performance cellulose-based materials.

SbPL1CE8 from Segatella bryantii combines with SbGH28GH105 in a multi-enzyme cascade for pectic biomass utilization

Pectinases are useful biocatalysts for pectic biomass processing and are extensively used in the food/feed, textile and papermaking industries. Two pectinase genes, a pectate lyase (SbPL1CE8) and a polygalacturonase (SbGH28GH105) were isolated from Segatella bryantii and functionally characterized. Recombinant rSbPL1CE8 was most active against polygalacturonic acid (PGA) and pectin with a 60 % degree of esterification, with kcat/Km values of 721.18 ± 64.77 and 327.02 ± 22.44 mL/s/mg, respectively. Truncated rSbPL1 acted as a mesophilic alkaline pectate lyase, which was highly resistant to inactivation by methanol and ethanol. The rSbPL1CE8 exclusively digested PGA and pectin into unsaturated digalacturonate (uG2), which was further converted into galacturonic acid by rSbGH28GH105. The rSbPL1CE8 was highly effective for saccharification of waste materials from Zea mays, Oryza sativa and Arachis hypogaea processing, and for ramie fiber degumming. This novel pectate lyase has great potential for application in industrial pectic biomass processing.

Analysis of Rhodamin B in Lipstick Preparations in Padangsidimpuan City by Thin Layer Chromatography (TLC) Method

Rhodamin B is a synthetic dye in the form of a crystalline powder, green or reddish-purple, odorless, and in solution will be bright red with fluorescence or fluorescence. Rhodamin B is commonly used as a dye in the textile and papermaking industries. Rhodamin B can cause irritation in short-term exposure and has carcinogenic effects. This study aims to find out whether there is Rhodamin B in lipsticks circulating in the Padangsidimpuan City market. Samples were taken by purposive sampling and 5 red samples were obtained. To identify the presence of Rhodamin B, a thin-layer chromatography method was used using eluene as the phase of motion, namely methanol, ethyl acetate, ammonia (50:20:25) and a 254 nm UV lamp The results of the study showed that out of 5 lipstick samples identified, there was one lipstick sample that was identified as containing Rhodamin B.

Reinforcements of cationic polyvinyl alcohol with low dosage for secondary fibre

ABSTRACT The effect of polyvinyl alcohol, a green water-soluble polymer, usually is not satisfied as a secondary-fiber reinforcing agent in pulp and paper-making industry due to the same negative charges of PVA and pulp fiber. In this study, 3-chloro-2-hydroxypropyltrimethylammonium chloride was used as an etherifying agent to prepare cationic modification of polyvinyl alcohol (CPVA) with degree of etherification of 0.059 under a reaction time of 4 hours and n(PVA : etherifying agent) = 1 : 0.5. Compared with PVA, CPVA exhibits positive charge and smaller particle size, enabling it to effectively combine with negatively charged fibers and get in between the fibers. As a result, CPVA demonstrates a remarkable ability to improve the paper’s physical properties. With a dosage of only 0.2% CPVA (based on the absolute dry pulp), which is merely 1/10 of the dosage of PVA, CPVA increases the paper’s tensile index by 54.09%, burst index by 25.96%, and tear index by 21.09%. CPVA as a reinforcing agent for secondary fiber pulps, which can be attributed to the alteration in charge, to enhance CPVA’s affinity for the electrostatic interaction of the fibers. Consequently, CPVA emerges as a viable and eco-friendly enhancement solution, demonstrating significant potential in secondary fiber reuse.

Fuzzy logic based thermal image processing for temperature monitoring of rotating cylindrical surfaces

When a non-contact and remote temperature measurement is of importance, several environmental factors must be considered. Of these, two are of crucial importance — the surface emissivity of the observed object and the directional emissivity in the object–sensor relationship. This paper proposes FDEM — a Fuzzy Directional Emissivity Model built with the assumption that the observed surface is cylindrically shaped. The model consists of two submodels — for vertical and horizontal directions separately. The main contribution of this paper is the formalization of a linguistic description of measurement conditions typical for an industrial environment. Additionally, dual linguistic fuzzy modifiers were used to increase the accuracy of the modeled emissivity. Finally, the proposed model achieved up to 40% reduction of RMSE error when used for correcting the temperature measurements of a rotating cylinder. Overall, our model provides a novel and reliable way for temperature readout correction on the entire surface of a drying roller, such as ones used in the papermaking industry. Furthermore, the proposed approach is not only inherently capable of compensating for the position of the camera, but also does it in an interpretable, and hence expert-verifiable, manner.

Fabrication and characterization of an alginate-based film incorporated with cinnamaldehyde for fruit preservation

Sodium alginate (SA) is widely used in the food, biomedical, and chemical industries due to its biocompatibility, biodegradability, and excellent film-forming properties. This article introduces a simple method for preparing uniform alginate-based packaging materials with exceptional properties for fruit preservation. The alginate was uniformly crosslinked by gradually releasing calcium ions triggered by the sustained hydrolysis of gluconolactone (GDL). A cinnamaldehyde (CA) emulsion, stabilized by xanthan without the use of traditional surfactants, was tightly incorporated into the alginate film to enhance its antimicrobial, antioxidant, and UV shielding properties. The alginate-based film effectively blocked ultraviolet rays in the range of 400–200 nm, while allowing for a visible light transmittance of up to 70 %. Additionally, it showed an increased water contact angle and decreased water vapor permeability. The alginate-based film was also employed in the preparation of coated paper through the commonly used coating process in the papermaking industry. The alginate-based material displayed excellent antioxidant properties and antimicrobial activity against Escherichia coli, Staphylococcus aureus and Botrytis cinerea, successfully extending the shelf life of strawberries to 7 days at room temperature. This low-cost and facile method has the potential to drive advancements in the food and biomedical fields by tightly incorporating active oil onto a wide range of biomacromolecule substrates.

Effect of Sheet Properties of Cellulosic Polyglycidyl Methacrylate-Grafted Fibers in a Cationic Polyacrylamide/SiO2/Anionic Polyacrylamide Retention Aid System.

As increasing fiber hydrophobicity can significantly improve the paper dewatering process, we found that replacing SBKP and HBKP with 0.5% superhydrophobic CPGMA can significantly improve the dewatering of paper sheets. Therefore, it can be concluded that if CPGMA has little effect on paper properties, it will have potential industrial value in the papermaking industry. Consequently, it is necessary to further study the effect of the CPGMAs@CPAM/SiO2/APAM system on paper properties. To evaluate the application potential of the system in the papermaking industry, we investigated the effects of CPGMAs, which replaced the fibers in the stocks, on the paper properties in the CPAM/SiO2/APAM system. The findings demonstrate that as the CPGMA replacement increased, the paper's tensile strength, bursting strength, tear resistance, and folding endurance all declined. The trend can be segmented into two phases: a rapid decrease for substitution amounts below 0.5% and a gradual decline for substitution amounts exceeding 0.5%. When replaced with a small amount of CPGMAs, there was a negligible effect on these properties. Second, the paper air permeability increased with the CPGMA substitution amount in the stock. Furthermore, the trend of paper air permeability can be divided into two stages-a rapid stage with a substitution amount of <0.5% and a slow stage with a substitution amount of >0.5%. A small amount of CPGMAs could distinctly improve the paper's air permeability. Third, CPGMAs, which replaced fibers in the stock, minutely affected the paper formation. A small amount of CPGMAs substantially boosted the efficacy of the process of paper manufacture and certain characteristics of the paper, and it had a negligible impact on the strength of paper. The CPGMAs@CPAM/SiO2/APAM technology has the potential to improve the retention and filtration performance of CPAM/SiO2/APAM.

Evolution law of conductivity value in wet-end system of recycled pulp and its regulation strategy

The closed cycle of white water in the paper-making process is an important way to reduce material loss, water consumption, and wastewater discharge. However, how to improve the quality of white water and increase the efficiency of white water recycling is still a challenge. Faced with the increasing conductivity value of white water in the process of white water circulation, in this study, the factors affecting the conductivity value of white water for recycled pulp and the strategies for regulating the conductivity value were investigated by simulating the white water circulation during the paper-making process. The experimental results indicate the accumulation of inorganic salts is one of the reasons for the increasing conductivity value of white water. When inorganic salts accumulate to dynamic equilibrium, the increase amplitude of conductivity caused by inorganic salts does not exceed 5 % of the initial conductivity. Under the white water circulation, the polyelectrolytes formed by degradated starch are the main factor for the continuous increasing conductivity value of white water. The retention of starch, during the paper-making process, can be improved by adding in-situ generated aluminum hydroxide colloids and the polyelectrolytes from starch degradation in white water can also be adsorbed by aluminum hydroxide precipitates. The effects of soluble organic matter and dissolved inorganic matter on white water conductivity were revealed, and the formation pattern of conductivity value in the wet-end system of recycled pulp was derived. At the same time, methods for removing organic matter and polyelectrolytes were proposed. Both are helpful to improve the quality of white water for paper-making industry and reduce the pollution of the wastewater.

Sida hermaphrodita Rusby as a papermaking raw material – Chemical and morphological characteristics

A continually increasing demand for papermaking materials and simultaneously growing disproportion between the request for fiber and the limited resources of wood have forced scientists and the papermaking industry to search for the new sources of fibrous raw materials. A new promising set of raw materials for papermaking comes from energy crops. This paper presents Sida hermaphrodita Rusby L., as a non-woody raw material for papermaking. From the studies of chemical composition, it follows that cellulose content of more than 40% characterizes phloem of stems and branches, whereas in xylem exhibits more than 32%. The lowest is the concentration of cellulose in leaves and flowers of Sida. The content of lignin is lower than 24% and 16% in stem xylem and phloem, respectively. In Sida, hemicelluloses and mineral substances stand for being not more than 30% and 2%, respectively. The morphology of Sida cells is similar to hardwood, with fiber length of 0.383, 0.470 and 1.025 mm for parenchyma, xylem, and phloem, respectively. The chemical composition of Sida hermaphrodita together with its morphological characteristics make this raw material suitable for a production of papers intended for printing, writing and tissue.

One pot green synthesis of Biginelli reaction catalysed by bio-waste metal-free super acid lignin sulphonate

A Bio-waste metal-free super acid catalyst (BWC) has been synthesized at higher temperature and used as a catalyst for synthesis of 3,4-dihydropyrimidine-2-(1H)-ones (DHPMs) via one pot three component Biginelli reaction. The multicomponent reactions are very complex and involves more than two reagents. In the present study, sulfonated carbonaceous material called a green catalyst was utilized for three component reaction. Catalyst was synthesized from sodium lignosulfonate which is obtained from the wastage of paper-making industries from the sulfite pulping process. The synthesized green catalyst was characterized by FT-IR, Thermal Gravimetric Analysis (TGA) scanning electron microscopy (SEM), Thermal Electronic microscopy (TEM), and elemental analysis. The three component Biginelli synthesis the catalyst was optimized to 8 mol % quantity which was sufficient to complete the reaction within 1–4 hrs. The yield of reaction ranges from 70-90 %. Separation was easy and recycling ability of catalyst was also tested with good retention of catalytical activity. Catalytic activity was performed as an acid-catalyzed reaction in ethanol. The synthesis of all the compounds were confirmed by 1H NMR (Nuclear magnetic resonance), MS (Mass Spectra), FT-IR (Fourier Transform Infrared), CHNS (Carbo, Hydrogen, Nitrogen, Sulphur) analysis. The satisfactory results were obtained with good yields, shorter reaction time and simplicity in the experimental procedure. The catalysts could be recycled and reused three times without decrease in the catalytic activity significantly.

Introducing sodium lignosulfonate as an effective promoter for CO2 sequestration as hydrates targeting gaseous and liquid CO2

Hydrate-based CO2 sequestration (HBCS) emerges as a promising solution to sequestrate CO2 as solid hydrates for the benefit of reducing CO2 concentration in the atmosphere. The natural conditions of high-pressure and low-temperature in marine seabed provide an ideal reservoir for CO2 hydrate, enabling long-term sequestration. A significant challenge in the application of HBCS is the identification of an environmental-friendly promoter to enhance or tune CO2 hydrate kinetics, which is intrinsically sluggish. In addition, the promoter identified should be effective in all CO2 sequestration conditions, covering CO2 injection as gas or liquid. In this study, we introduced sodium lignosulfonate (SL), a by-product from the papermaking industry, as an eco-friendly kinetic promoter for CO2 hydrate formation. The impact of SL (0–3.0 wt.%) on the kinetics of CO2 hydrate formation from gaseous and liquid CO2 was systematically investigated. CO2 hydrate morphology images were acquired for both gaseous and liquid CO2 in the presence of SL for the explanation of the observed promotion effect. The promotion effect of SL on CO2 hydrate formation is optimal at 1.0 wt.% with induction time reduced to 5.3 min and 21.1 min for gaseous and liquid CO2, respectively. Moreover, CO2 storage capacity increases by around two times at 1.0 wt.% SL, reaching 85.1 v/v and 57.1 v/v for gaseous and liquid CO2, respectively. The applicability of SL as an effective kinetic promoter for both gaseous and liquid CO2 was first demonstrated. A mechanism explaining how SL promotes CO2 hydrate formation was formulated with additional nucleation sites by SL micelles and the extended contact surface offered by generated gas bubbles or liquid droplets with SL. The study demonstrates that SL as an effective promoter for CO2 hydrate kinetics is possible for adoption in large-scale HBCS projects both nearshore and offshore.

Interactions of NaCl with cellulose I$$\beta$$ crystal surfaces and the effect on cellulose hydration: a molecular dynamics study

AbstractCrystalline nanocellulose is widely used for example, in the paper-making and food industries, as support matrix material or reinforcement of polymer materials, but also in drug carrier and nanomedicine applications. Interestingly, aqueous solutions of cellulose are extremely sensitive to small amounts of added salt yet mere considerations of charge screening leave open questions regarding the mechanisms, especially for unmodified cellulose in aqueous solutions. Here, we map NaCl ion distributions and the effect of added NaCl salt on the hydration of I$$\beta$$ β cellulose nanocrystal (CNC) surfaces by atomistic detail molecular dynamics simulations with explicit water solvent. The simulations reveal the dependency of the hydration layers of the six surfaces of CNCs on the ions, as well as NaCl ion binding sites, and preferences in terms of binding free energy for the ions near CNC surfaces at different NaCl concentrations. We discuss the modelling results against our prior rheology characterization of cellulose solutions. Together, the results indicate that the high sensitivity of cellulose aqueous solutions to added salt rises from the ions near the surface changing locally the ordering and structure of the hydration layers of the CNC surfaces. The revealed mechanism of salt-induced viscosity changes in cellulose aqueous solutions allows advanced design of gelling CNC systems for various end uses and may also guide tuning cellulose interactions by different solvent environments.

Rational design of biomass-derived and UV-curable dynamic polymer for the encapsulation of paper-based flexible strain sensor

The paper-based flexible electronic devices with the virtues of light weight, porousness, sustainability and low cost by paper-making technology, however its application may be restricted by the poor tolerance of water due to the abundance of hydroxyl group of cellulose fibers. The encapsulation of such device requires to keep its sustainability and match the high efficiency of paper-making industry. In this work, a series of biomass-derived and UV-curable dynamic polymers were synthesized using itaconic acid and binary alcohols as raw materials. The diglycidyl ethers were firstly synthesized through the substitution reaction between binary alcohols and epichlorohydrin. The oligomer was then prepared by ring-opening reactions between the diglycidyl ethers and glycidyl-methacrylate-modified itaconic acid precursor. The dynamic polymers were finally obtained from photo-initiated polymerization, of which the mechanical property was regulated by the length of the binary alcohols. It is found that the polymer from 1,10-decanol possessed the highest tensile strength of 5.8 MPa and biggest elongation at break of 4.1%. The polymer can be self-healed and recycled, and was proved to be used as a photoresist for printed circuit board (PCB). Furthermore, the polymer was successfully applied to encapsulation of paper-based flexible strain sensor, which exhibited hydrophobicity and significantly higher working stability under high humidity or human sweating condition. The strategy reported in this work may pave a way for the development of sustainable thermosetting polymers and sustainable flexible electronic devices with high performance.

Microwave-assisted pyrolysis of waste lignin to prepare biochar for Cu2+ highly-efficient adsorption: Performance, kinetics and mechanism resolution

Alkali lignin is the major byproduct of the paper-making industry and biorefining processes. However, due to its complex structure and low reactivity, most alkali lignin is still discharged as “black liquor” or directly incinerated, resulting in significant waste of bioresources and severe environmental pollution. In this study, biochar was prepared from alkali lignin using microwave-assisted pyrolysis, and its adsorption performance and mechanism for Cu2+ were investigated. The experimental findings demonstrate that the adsorption of Cu2+ onto biochar follows the pseudo-second-order kinetic model and the Langmuir isotherm model, suggesting that the adsorption process is predominantly governed by the chemisorption mechanism. Furthermore, the qm ranged from 405.55 to 492.75 mg·g−1, which is significantly higher than many other reported biochars. The adsorption mechanism includes mineral co-precipitation, DOM (mainly humic substances) adsorption, surface complexation, as well as ion exchange. The contribution of co-precipitation and surface complexation reaches 86.6 %, indicating that this biochar poses a low environmental risk. Thus, this study shows that alkali lignin could be a valuable bioresource for mitigating the environmental impact arising from Cu2+ pollution.

A one-stone-two-birds strategy to lignin-derived porous carbon for supercapacitor electrodes

The utilization of biowaste-derived porous carbon in supercapacitors has emerged as a promising approach to address the environmental concerns as well as harnessing the value-added potential of renewable biomass resources. Within this context, lignin, an abundant component of biomass and by-product of papermaking industry, presents substantial opportunities. In this paper, the Fe3C nanoparticle-embedded porous carbon (HPC-X) derived from lignin via a one-stone-two-birds strategy by used potassium ferrite (K2FeO4) as active agent. The as-prepared HPC-2 sample possesses a multi-hierarchical porous structure with a large specific surface area (2351.6 m2 g−1) and a cumulative pore volume of 1.44 cm3 g−1, where the specific capacitance of 236 F g−1 at 0.5 A g−1. The capacitance retention rate is still 94 % even after 20,000 cycles at 10 A g−1, suggesting its excellent long-time stability. This strategy paves the way for the cost-effective production of environmentally friendly and renewable carbon materials derived from biomass, and meanwhile, holds great promise for their application in advanced energy storage fields.

The impact of EID policy and trade on the environmental effects of Chinese paper enterprises from the perspective of financial constraints

Accompanying China's accession to the World Trade Organization, the rapid development of the Chinese economy has led to increasingly serious environmental issues. However, the inherent mechanisms underlying the impact of Environmental Information Disclosure (EID) policy and trade on the environmental effects of Chinese paper enterprises remain unclear in the context of the era's requirement for a resource-conserving and environmentally-friendly society. The pollution problem in the papermaking industry has received attention worldwide, and how to balance the environmental and development issues of papermaking enterprises is an urgent issue that needs to be solved in the academic community. This study explores the impact mechanisms of EID policy and trade on the environmental effects of enterprises from the perspective of financial constraints. Utilizing the PSM-DID model, the study investigates the moderating effects of financial constraints on the EID policy and import-export trade. The findings reveal that both external and internal financial constraints have negative, detrimental effects on the environmental effects of the EID policy and trade. These constraints impede research and development investment and technological upgrades, hinder productivity improvement, and hamper the realization of “regulatory and trade innovation effects”. This study enriches our understanding of the mechanisms by which trade affects the environmental effects of Chinese paper enterprises and further identifies the impacts of Chinese EID policy and trade on pollution emissions by enterprises, providing a theoretical basis and practical foundation for the government in formulating financial, environmental, and trade policies.

Correction to: Eliminating congestion in China’s papermaking and paper products industry: from both the perspective of increasing and decreasing inputs

Correction to: Eliminating congestion in China’s papermaking and paper products industry: from both the perspective of increasing and decreasing inputs

Upcycling of lime mud into lightweight artificial aggregates through the crushing technique

Lime mud (LM), a solid waste generated in the paper-making industry, was proposed to manufacture lightweight artificial aggregates (LAAs) via the crushing technique. LAAs with a loose bulk density of 765–885 kg/m3, an apparent density of 1270–1445 kg/m3, and a strength of 5.7–7.2 MPa were achieved. To optimize the crushing-consumption energy and the mechanical properties, the mix proportions and curing ages of the LAAs before crushing were comprehensively investigated through mineralogy and microstructure analyses. In addition, the embodied carbon and material costs of the manufactured LAAs were estimated. Results showed that the early-crushed LAAs (curing till 28 days) enabled achieving the higher 28-day strength compared to the 28-day-crushed LAAs; however, the early-crushed LAAs tended to produce more contents of powder. The incorporation of silica fume (SF) reduced the contents of crushing powder and refined the pore characteristics of the LAAs. An optimized mix proportion (LM:cement:SF = 5:3:2) of the LAAs crushed on day 3 showed the best comprehensive properties, considering the mechanical properties, material costs, energy consumption, and embodied carbon. Overall, this study offers insight into the LAA production via the crushing technique and the value-added use of LM in the construction industry.

Facile Strategy for Boosting of Inorganic Fillers Retention in Paper.

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO3) as a filler to boost paper's brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO2 nanospheres, TiO2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper.

Preparation of chitosan derivative and its application in papermaking

To improve the paper strength, a number of resins and polymeric materials are being used, which is not environmental friendly and sustainable. Therefore, bio-based paper additives for the papermaking industry are essential. In this investigation, a water soluble biopolymer like carboxymethyl chitosan (CMCh) was prepared. The degree of substitution of the prepared CMCh was 2.49. The solubility of the prepared CMCh was 2.0 (w/v) % at 50 °C, and the conductivity increased with the increase of CMCh concentration in water. The prepared CMCh was applied as dry and wet strength agent of unrefined and refined softwood pulps. Both pulp increased dry and wet strength with increasing CMCh dose. An addition of 2.0 % CMCh increased dry strength by 125 % and wet strength by 293 % of unrefined pulp. On the other hand, the dry and wet tensile index of refined pulp increased from 59.48 N·m/g to 66.11 N·m/g and 2.48 N·m/g to 3.47 N·m/g, respectively, with the addition of 1.0 % CMCh. The CMCh was also used in filler modification. The precipitated calcium carbonate (PCC) modified with CMCh increased the ash content in paper with improved strength properties. The CMCh can be used in papermaking both for improving paper strength and filler retention.