Editorial
Volume 41, Issue 2 , June 2026
Research Paper
Pulp and paper
Ramin Vaysi
Abstract
Background and aim: Fluting paper and Kraft liner paper are among the most important grades of paper produced in the pulp and paper industry, particularly for the manufacture of corrugated board. Fluting paper is typically made from a mixture of hardwood fibers using the Neutral Sulfite Semi-Chemical ...
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Background and aim: Fluting paper and Kraft liner paper are among the most important grades of paper produced in the pulp and paper industry, particularly for the manufacture of corrugated board. Fluting paper is typically made from a mixture of hardwood fibers using the Neutral Sulfite Semi-Chemical (NSSC) pulping process adding some softwood pulp, while kraft liner paper is produced from similar raw materials through the Kraft pulping process also adding some softwood pulp. However, due to limitations in wood supply and competition for primary raw materials, a significant portion pulp for these papers in Iran is recycled fibers, such as OCC and converting mill rejects. This study employs Gas Chromatography-Mass Spectrometry (GC-MS) to precisely identify and compare the organic compounds present in corrugated paper and kraft liner paper. The primary aim of this research is to evaluate the impact of various chemical constituents on the structural and functional properties of these two types of papers. Additionally, the study attempt to find these chemical roles in optimizing production processes and improving the overall quality of the final product within the paper manufacturing industry.Materials and Methods: In this study, fluting paper samples were collected from the production line of machine No. 2 at Mazandaran Wood and Paper Mill, and kraft liner paper samples were obtained from Chooka paper mill in Gilan. Initially, the ash content and extractable substances in the samples were quantified according to TAPPI standards. The extractable substances were then separated from the paper pulp using acetone as a solvent. The remaining extracts were transferred to glass vials, to which BSTFA (N, O-Bis(trimethylsilyl)trifluoroacetamide) reagent was added. The samples were heated in a water bath at 70°C for one hour before being injected into the GC-MS system for analysis. Compound identification was performed using retention time chromatograms, the Quats index and Adams table.Results: GC-MS analysis of the fluting paper identified a total of 76 compounds, with the most abundant being benzaldehyde (20.44%), benzene methanol (5.32%), 9-octadecenoic acid (5.16%), bis(2-ethylhexyl) phthalate (4.33%), gamma-sitosterol (1.34%), and beta-sitosterol (1.01%). These compounds primarily consisted of aromatic hydrocarbons and natural fatty acids. In contrast, GC-MS analysis of kraft liner paper identified 28 compounds, with the major components being bis(2-ethylhexyl) phthalate (28.21%), hexadecanoic acid (24.25%), 9-octadecenoic acid (11.67%), octadecanoic acid (10.45%), hexadecane (7.12%), pimaric acid (2.06%), 1,2-benzenedicarboxylic acid (1.17%), squalene (1.40%), and syringyl aldehyde (0.31%). These substances were predominantly industrial plasticizers and fatty acids, which play an important role in the composition and functional properties of Kraft liner paper. The GC-MS analysis of fluting paper also revealed the presence of compounds such as p-xylene, benzaldehyde, dibenzyl, formylmorpholine, and benzyl alcohol, which were not detected in kraft liner paper. Additionally, light alkanes (such as decane, dodecane, and nonadecane) and phytosterols, specifically beta- and gamma-sitosterol, were uniquely present in fluting paper, supporting the hypothesis of differences in fiber sources or the use of specific additives in fluting paper production. In contrast, phenolic and aromatic compounds detected in fluting paper may be derived from adhesives, inks, or residual chemicals in the manufacturing process. For kraft liner paper, compounds such as abietic acid, pimeric acid, and isocunabic acid were identified, which were absent in fluting paper. Additionally, long-chain hydrocarbons such as tetracosane and squalene were found specifically in this sample, indicating the potential use of softwood fibers or non-fibrous additives like rosin.Conclusion: The comparison of GC-MS profiles between fluting paper and kraft liner paper revealed that both grades of paper share common chemical constituents, including long-chain alkanes and natural fatty acids. Furthermore, bis(2-ethylhexyl) phthalate, an industrial plasticizer, plays a significant role in improving the mechanical properties of both paper types. The observed differences in specific compounds, such as the presence of aromatic compounds and light alkanes in fluting paper and long-chain hydrocarbons and resins in kraft liner paper, suggest variations in fiber sources, pulping processes, and the use of additives. These differences could provide valuable insights for optimizing paper formulations and enhancing the quality of paper products.
Research Paper
Physics and anatomy
Majid Kiaei; sadegh karimi
Abstract
Background and Objectives: Poplar (Populus nigra) is widely used in afforestation programs due to its rapid growth and easy availability, making it an important source of raw material for wood-based industries. This study aimed to evaluate and compare the physical, anatomical, and chemical properties ...
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Background and Objectives: Poplar (Populus nigra) is widely used in afforestation programs due to its rapid growth and easy availability, making it an important source of raw material for wood-based industries. This study aimed to evaluate and compare the physical, anatomical, and chemical properties of stem and branch wood of this species, as well as to examine their variation along the branch axis.Materials and methods: ،Three trees were selected and from each tree, one sample at breast height of the stem and three samples from three branches at different elevation of the tree were taken. Fiber length, fiber diameter, cell-wall thickness, lumen diameter, biometric indices, vessel diameter, wood density, lignin, cellulose, hot-water extractives, and alcohol–acetone extractives were measured using appropriate preparation and test methodsResults: The results showed that all measured properties differed significantly between stem and branch wood. Stem fibers are longer, diameter, and wall thickness are wider, indicating a higher level of anatomical maturity. In contrast, branch wood with its smaller fibers exhibited higher slenderness ratio and Runkel ratio. Branch wood also showed fairly higher density, while vessel diameter was larger in the stem and displayed a decreasing trend from the base to the tip of the branch. Chemically, cellulose, lignin, and extractive contents were all higher in stem wood, whereas these components declined gradually along the branch.Conclusion: Overall, the findings indicate that stem wood, due to its structural maturity and higher lignocellulosic content, is more suitable for wood and paper applications. However, branch wood owing to its higher density, acceptable papermaking indices, and adequate fiber characteristics can serve as an economical and accessible supplementary source for pulp production. These results highlight the potential role of branches in improving raw-material utilization and promoting sustainable wood-resource management
Research Paper
Chemistry of wood
Seyed Eshagh Ebadi
Abstract
Background and Purpose: Due to the limited availability of raw materials required by Iran’s wood and paper industries, the utilization of lignocellulosic resources such as bagasse, reed, bamboo, cotton linters, cotton, kiwi pruning waste, rapeseed waste, and others plays a vital role in the country’s ...
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Background and Purpose: Due to the limited availability of raw materials required by Iran’s wood and paper industries, the utilization of lignocellulosic resources such as bagasse, reed, bamboo, cotton linters, cotton, kiwi pruning waste, rapeseed waste, and others plays a vital role in the country’s fiber sector. Among these, bamboo and reed—being renewable resources—should not be overlooked, as their stalks can supply a portion of the non-wood lignocellulosic materials of Iran's industries. This study was conducted to identify the mineral elements and chemical components of organic matter (in reed and bamboo stalks).Materials and methods: Thirty reed and bamboo stalks were selected and harvested from the western region of Mazandaran. Initially, stalks flour and ash content were prepared according to TAPPI standard methods. The types and concentrations of mineral elements were determined using 63% nitric acid and an atomic absorption spectrometer. Then, the extractive content of the samples was measured. The extractives were isolated using acetone solvent, and the remaining extract was transferred to a glass vial. BSTFA reagent was added, and the samples were heated in a water bath (bain-marie bath) at 70°C for one hour, followed by injection into the GC-MS system. Compound identification was based on the retention-time diagram, calculation of the Kovats index, and comparison with the Adams table.Findings: The results indicated that bamboo stalks had higher absorption levels of zinc, copper, and magnesium ions compared to reed. Conversely, reed stalks showed higher absorption of iron, lead, potassium, and manganese ions. GC-MS analysis revealed 96 compounds in reed stalks, with 2-Phenyl-N-methylaniline (25.99%), benzaldehyde (20.70%), 1,2-benzenedicarboxylic acid (11.48%), and xylene (1.16%) being the most prominent. In bamboo stalks, 104 compounds were identified, with benzaldehyde (46.43%), iron monocarbonyl (1.94%), bibenzyl (1.58%), and vanillin (0.09%) being the most abundant.Conclusion: The findings showed that magnesium had the highest absorption in reed, while lead had the lowest in bamboo. Chromatogram analysis identified nine compounds—xylene, benzaldehyde, benzyl chloride, benzene methanol, dodecane, tetradecane, bibenzyl, octadecane, and 1,2-benzenedicarboxylic acid—as common to both reed and bamboo. Vanillin and iron monocarbonyl were specific to bamboo, while bis (2-ethylhexyl) phthalate and gibberellin A3 were specific to reed. Among these, benzaldehyde was the most prevalent compound in both plants, indicating its potential role in the future applications of reed and bamboo stalks.
Research Paper
Physics and anatomy
Mohammad Emaminasab; Meysam Mehdinia; Hashem Rahamin; Kamyar Salehi; Roshanak Khatib Eghdami
Abstract
Background and Objectives: Wood, as one of the most fundamental, renewable and biological materials, has played an important role in the development and advancement of human civilization. Accurate identification of archaeological wood can reveal patterns of natural resource exploitation and adaptive ...
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Background and Objectives: Wood, as one of the most fundamental, renewable and biological materials, has played an important role in the development and advancement of human civilization. Accurate identification of archaeological wood can reveal patterns of natural resource exploitation and adaptive strategies of past populations to their surrounding environments. It also provides direct evidence for reconstructing past vegetation cover, timber trade networks, and the extent of human impact on ecosystems. Accordingly, the main objective of this study was the scientific identification of archaeological wood specimens recovered from excavations in the Mansur-abad region, Yazd Province, Iran.Materials and Methods: Six archaeological wood samples (three wooden scaffolding, two wooden basket, and one wooden shoe) obtained from the Geological Museum of the Geological Survey and Mineral Exploration were examined. Small samples were carefully removed from each specimen in accordance with museum regulations to minimize damage. For anatomical analysis, samples were softened in a solution of 98% ethanol, water, and glycerin. Thin sections (15 µm thick) were prepared in transverse, radial, and tangential sections using a sliding microtome. Sections were stained with 1% safranin solution, mounted on slides, and examined under a light microscope. Fiber maceration was carried out using Franklin’s method to measure cellular dimensions. Anatomical features were analyzed according to the feature list provided by the International Association of Wood Anatomists (IAWA).Results: All samples exhibited distinct growth ring boundaries. The basket sample, derived from a one-year-old branch with a single growth ring, contained less secondary xylem, and vessels were mostly solitary and occasionally radially arranged. In the wooden shoe sample, vessels showed a diagonal arrangement and were predominantly grouped in tangential and cluster patterns, especially in latewood. In the scaffolding samples, more than 90% of vessels were exclusively solitary. All specimens displayed simple perforation plates and alternate inter-vessel pits with diameters predominantly ranging from 4–7 µm. Helical thickenings, particularly in narrow vessels, and the presence of vascular tracheids were observed in all samples. Axial parenchyma was diffuse in the basket and scaffolding samples, and paratracheal in the shoe sample. Rays were generally wide and multi-seriate; they were homogeneous with procumbent cells in the scaffolding samples and heterogeneous in the others. Fiber maceration indicated longer vessel elements in the basket sample and shorter ones in the scaffolding and shoe samples. Evidence of biological degradation was observed in the cell walls of all specimens.Conclusion: Based on anatomical and morphological characteristics, the basket sample was identified as Amygdalus sp., the wooden shoe as Celtis sp., and the scaffolding samples as Elaeagnus angustifolia. Wild almond (Amygdalus scoparia) has a long, straight, and highly flexible shoots, making it one of the suitable species for basketry. In addition, the wood of Celtis has been appropriate for the manufacture of wooden footwear, and Elaeagnus angustifolia was a suitable choice for wooden mine scaffolding in the past time, due to its favorable physical and mechanical properties. Considering the distribution of these trees and shrubs in Yazd Province, whether cultivated or naturally occurring, their use in architectural structures and handicrafts reflects the detailed knowledge and efficient utilization of locally available woody resources by past communities.
Research Paper
Nano composite
Sead Majid Zabihzadeh; Seyedeh Motahareh Mohseni Shektai; Maryam Ghorbani Kokandeh; Ghasem Asadpur
Abstract
Background and Objective: The extensive use of petroleum-based polymers in the packaging industry and their non-biodegradable nature, has led to the accumulation of persistent waste, contamination of soil and surface waters, and ultimately the degradation of ecosystems. In this context, biopolymers - ...
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Background and Objective: The extensive use of petroleum-based polymers in the packaging industry and their non-biodegradable nature, has led to the accumulation of persistent waste, contamination of soil and surface waters, and ultimately the degradation of ecosystems. In this context, biopolymers - particularly pectin extracted from citrus peels as an agricultural by-product - have emerged as suitable alternatives to conventional synthetic polymers. The extraction of pectin using organic acids such as citric acid represents a green and sustainable approach, owing to its safety, environmental compatibility, and ability to produce materials of appropriate quality. However, films made from neat pectin generally exhibit limitations in mechanical strength and barrier performance. Cellulose nanofibrils, due to their high elastic modulus, favorable tensile strength, and biodegradability, can be effectively employed as reinforcing agents within pectin matrices. The aim of this study was to fabricate and characterize pectin/CNF bionanocomposite films with enhanced properties for biodegradable packaging applications.Methodology: Pectin with a degree of esterification of 61.63% was extracted from lemon peel using citric acid, and cellulose nanofibrils (CNF) were supplied by NanoNovin Polymer Co. Films were prepared using the solution casting method. Briefly, pectin was dissolved in distilled water at 70 °C, glycerol was then added as a plasticizer, and the pH of the solution was adjusted to 4. Simultaneously, CNF was dispersed in distilled water at concentrations of 1, 3, and 5% (w/w) and subjected to ultrasonication for 30 min to ensure uniform dispersion. The CNF suspension was subsequently added to the pectin solution, and the mixture was homogenized for 25 min. After degassing in a vacuum oven, the film-forming solutions were cast into Petri dishes and dried for 48 h in a desiccator containing a saturated magnesium nitrate solution (52.8% relative humidity at 25 °C). The tensile properties, optical properties, thickness, water vapor permeability, and moisture absorption of the films were evaluated. Neat pectin films and films containing 5% CNF were selected for Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses. Statistical analysis of the data was performed using SPSS software.Results: The results demonstrated that the incorporation of cellulose nanofibrils (CNF) had a significant effect on the properties of pectin-based films. The Young’s modulus increased from 3.12 MPa for the neat pectin film to 8.08 MPa for the film containing 5% CNF. Likewise, the tensile strength increased from 1.42 to 2.60 MPa, and the tensile energy absorption increased from 12.94 to 22.43 J, indicating a simultaneous improvement in stiffness, strength, and toughness of the system. The water vapor permeability decreased by approximately 51% upon the addition of 5% CNF, from 4.54 × 10⁻¹¹ to 2.22 × 10⁻¹¹ g/m·s·Pa, demonstrating a substantial enhancement in barrier performance comparable to that of cellophane. In addition, the moisture absorption of the films decreased to 25.35% at a CNF content of 5%. In contrast, increasing the CNF content resulted in a reduction in film transparency from 98.26% to 80.09%. FTIR analysis confirmed the formation of strong hydrogen bonds between CNF and the pectin matrix. XRD patterns revealed an approximately 73% increase in diffraction intensity, indicating an improvement in the degree of crystallinity. Furthermore, SEM micrographs confirmed the relatively uniform dispersion of cellulose nanofibrils and good interfacial compatibility between CNF and the pectin matrix.Conclusion: The findings of this study demonstrated that pectin/cellulose nanofibril bionanocomposite films provide a favorable combination of mechanical and barrier properties. The enhanced performance of this system can be attributed to the formation of strong hydrogen bonds between the pectin matrix and CNF, an increased degree of crystallinity, and the development of a three-dimensional reinforcing network. Accordingly, pectin/cellulose nanofibril films represent a promising biodegradable alternative to conventional plastic packaging materials and can contribute effectively to reducing the environmental impacts of packaging waste within the framework of the circular economy and sustainable development.
Research Paper
Wood Modification and Wood Preservation
Reza Hajihassani; Sead Masoumeh Zamani; Fardad Golbabaei
Abstract
Background and objectives: The purpose of this study was to investigate the effect of heat treatment on bio-durability and some physical and mechanical properties of two wood species (Fraxinus Sp. and Picea Sp.). So, thermo-wood samples were prepared from Fraxinus Sp. and Picea Sp. based on thermo-D ...
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Background and objectives: The purpose of this study was to investigate the effect of heat treatment on bio-durability and some physical and mechanical properties of two wood species (Fraxinus Sp. and Picea Sp.). So, thermo-wood samples were prepared from Fraxinus Sp. and Picea Sp. based on thermo-D process. Heat-treated and untreated wood specimens were evaluated after exposing to white rot fungus for 16 weeks. The laccase activity and its effect on mass loss and wood density were also investigated. Moreover, some mechanical properties include impact strength and compression parallel to grain of both wood specimens was measured before and after exposing to fungus. The results showed that thermally modification improves the bio-durability of both wood species. The results also revealed reduction of mechanical properties due to heat treatment except compression parallel to grain.Materials and methods: In current study, the wood specimens were prepared from Ash and spruce woods. First, the prepared specimens were heat treated based on thermo-D process. Then, to investigate the biological resistance as well as physical and mechanical properties measurements, several specimens were prepared from heat treated and untreated wood. White rot fungus (Trametes versicolor) was used to evaluate the biological resistance of wood samples. Malt extract agar was also used as a culture medium. After preparing the white rot fungus, they were initially transferred on the culture medium in kolle dishes and then were placed inside the germinator to cover the surface of culture medium. Afterwards, the heat treated and untreated wood samples were exposed to the fungus and finally kolle dishes containing wood and fungus samples were transferred to the germinator. After 16 weeks, all specimens were taken from the germinator out and evaluated their physical and mechanical properties as well as biological resistance. The experiments included measurement of laccase activity, mass loss, density, impact strength and compression parallel to grain. The applied standards for physical, mechanical, and biological resistance experiments included EN113, ASTM D143-09, and ASTM D256. Eventually, the obtained results were statistically analyzed based on ANOVA method by SPSS software.Results: The results showed that the white rot fungus has been more efficiency on untreated specimens compared to thermo-wood in both wood species (Fraxinus Sp. and Picea Sp.). Therefor heat treatment improved the biological resistance, and also causes some changes in physical and mechanical properties of Ash and Spruce wood. The results also showed that thermal modification at high temperatures not only reduces the density of both woods, but also inhibited the reduction effect on density due to white rot fungus activity. Moreover, the results revealed that the compression parallel to grain of specimens was increased by heat treatment. On the other hand, reduction of this mechanical property due to the white rot fungus activity in thermo-wood samples was less than the controls. Evaluation of impact strength of specimens showed negative effect of heat treatment on this mechanical property. In addition, reduction of impact strength after exposure to the white rot fungus in heat treated specimens was higher than untreated.Conclusion: Based on the results, thermal modification can generally causes improvement of biological resistance, reduction of some physical and mechanical properties as well as more stability of applied properties of Ash and Spruce wood which is exposed to the white rot fungus.
