Iranian Journal of Wood and Paper Science Research

Public Titles

1403-3

Volume 39, Issue 3 , October 2024

https://doi.org/10.22092/ijwpr.2024.131956

Abstract

Public Titles

Editorial

Volume 39 Issue 3 autumn - Serial Number 88

Volume 39, Issue 3 , October 2024

https://doi.org/10.22092/ijwpr.2024.131952

Abstract

Management and Economics Wood Management and Economics wood

The effect of marketing capabilities, innovation and learning ability of employees on the performance of wooden office furniture companies

Amir Reza Taheri; Abbas Tamjidi; Ajang Tajdini

Volume 39, Issue 3 , October 2024, Pages 163-180

https://doi.org/10.22092/ijwpr.2022.357201.1706

Abstract

Background and Objectives: Organizations depend on marketing, innovation and learning indicators to increase organizational performance and competitive advantage. By taking advantage of appropriate marketing and innovation capabilities, in addition to profitability and competitive ... Read More Background and Objectives: Organizations depend on marketing, innovation and learning indicators to increase organizational performance and competitive advantage. By taking advantage of appropriate marketing and innovation capabilities, in addition to profitability and competitive advantage, product life cycle prolongation and stability in the competition scene are provided for organizations. The rapid changes in production technologies necessitate the strengthening of human resource capabilities for all elements. Organization is necessary. Methodology: The effect of marketing capabilities, innovations, learning of employees on the performance of wooden office furniture companies with the approach of structural equations has been investigated. The statistical population of this research consists of managers and engineers working in wooden office furniture companies located in industrial towns in Tehran and Alborz provinces. Sampling method was classified and Crecy-Morgan table was used to determine the sample size (92 people). Initial effective indicators were selected by studying the available sources and the conceptual model of the research considering the performance of the organization (company) as a dependent variable and marketing, innovation and learning variables as independent variables. The main tool for collecting information for this research was a questionnaire. Correlation and confirmatory factor analysis and structural equation modeling based on partial least squares method were used to investigate the research hypotheses and analyze the structural relationships between variables. Results: The results showed that innovation, marketing and learning capabilities had a positive effect on the performance of wooden furniture companies. In addition, these capabilities complement 96.9% of the changes in the dependent variable of the company's performance. The results of the model quality evaluation index show that marketing capability (strong effect), innovation capability (medium effect), learning capability (weak effect) have the greatest impact on company performance. Finally, the results of this study remind the various companies producing wood furniture industry products that are constantly looking to export their goods that, unlike the somewhat non-competitive domestic market, to compete with other companies in target markets, should try. Due to factors such as marketing, innovation and learning, improve products quality, reduce costs and ultimately increase company performance. Conclusion: The use of appropriate marketing methods, innovative capabilities and increasing human resource capabilities in order to strengthen organizational learning in wooden furniture industry companies will strengthen the performance and position of the mentioned companies.

Research Paper Pulp and paper

Use of Local Produced Papers as Base Paper for Making Wallpaper

Seyed Mehdi Manzour-olajdad; Omid Ramezani

Volume 39, Issue 3 , October 2024, Pages 181-197

https://doi.org/10.22092/ijwpr.2024.362850.1756

Abstract

Background and Objectives: Our country has been importing various kinds of wallpaper from different countries for many years. With the increase of foreign exchange problems, the local production of wallpaper and its self-sufficiency has been proposed as a suitable solution. On the other hand, currently, ... Read More Background and Objectives: Our country has been importing various kinds of wallpaper from different countries for many years. With the increase of foreign exchange problems, the local production of wallpaper and its self-sufficiency has been proposed as a suitable solution. On the other hand, currently, domestic companies are producing paper from white waste paper, which is not justified for use as printing and writing grades due to many problems. However, many companies in the country are producing white grades from white waste paper, the use of which as a base paper in the production of decorative paper or wall paper has not been scientifically investigated. The purpose of this research is to study and investigate the possibility of producing wall paper from recycled white paper produced in the country.Methodology: The stages of this project were carried out in 6 separate and consecutive phases, which include: 1) determining the quality characteristics of the papers; 2) preparation of coating material formulation with starch as binder; 3) preparation of coating material formulation with latex and starch as binder; 4) coating of papers with the prepared coating formulations ; 5) Coating papers and non-woven fabric (Non-Woven) with polyvinyl chloride (PVC); 6) Application of four-color printing on the selected samples of coated papers. For this purpose, first, samples of papers produced by several Iranian companies were acquired and they were transferred to the laboratory of Biosystems and Bioproducts of Shahid Beheshti University for coating and performing the necessary treatments. In order to perform the mentioned treatment on the paper samples, various chemical substances were used, including calcium carbonate powder, kaolin, titanium oxide, corn starch, latex and PVC powder. With this aim, coating solutions with different percentage of solids were prepared steadily and with trial and error using various combinations of these materials (with a total of 110 and 124 parts). Then, these coated solutions were added on various domestic base papers (mostly recycled). Finally, the image of a flower was printed in four colors on the most desirable coated papers.Results: In determining the quality characteristics of base papers, including measurements of water absorption, ash content, thickness, permeability to air, tensile strength, tear resistance index and burst resistance index, two paper samples produced by two companies of Pardis Paper and Tabriz paper were selected as the best and considering the amount of ash, Tabriz paper was introduced as the base paper more suitable than other local papers. Further, after applying the coating material, coated papers with a relatively favorable appearance and whiteness percentages of about 60 to 85 were obtained, and finally, based on the results, a significant relationship was found between the increase in the solids percentage of the coated solutions and the whiteness percentage of the coated paper. Also, after the printing operation on the selected samples, Rasha Superkraft and Tabriz Kraft papers were introduced as the best samples. Also, the highest quality of printing was reached with PVC on Pars white paper with 16% PVC, on whitetop Rasha with 28% PVC and on non-woven fabric (non-woven fabric) with 28% PVC compared to the weight of the paper.Conclusion: The conclusion of the results of this research are listed below:A) The best solid percentage of coating solution (concentration of the mixture) was 41-46%.b) The best combination of binder and pigment, equal to 100 + 12 + 12 = 124 parts and the ratio of the dry weight of the coating mixture added to the dry weight of the base paper is equal to 12%.c) The highest whiteness obtained by adding calcium carbonate + titanium oxide + starch.t) The most suitable concentration of starch that can be used in the coating solution is 15%.c) The best coating and uniform and good coating appearance was obtained on Rasha Superkraft paper with the formula: kaolin + titanium oxide + latex with a whiteness of 77.7% and on Tabriz kraft paper with the formula: kaolin + titanium oxide + latex, with a whiteness of 71.8%. If higher whiteness is desired, using calcium carbonate instead of kaolin would give a better result.

Research Paper Physics and Mechanical Wood

Investigating the effect of knot size on the dynamic modulus of elasticity of beech wood (Fagus orientalis Libsky)

Javad Torkaman; Ramin Naghdi

Volume 39, Issue 3 , October 2024, Pages 198-212

https://doi.org/10.22092/ijwpr.2024.365915.1774

Abstract

Background and purpose: Dynamic methods (non-destructive) work on the basis of creating tension without failure in the samples and save time and costs for evaluating mechanical properties. Knots or the encapsulated branches are the most important factor in the grading of wood. Therefore, the objectives ... Read More Background and purpose: Dynamic methods (non-destructive) work on the basis of creating tension without failure in the samples and save time and costs for evaluating mechanical properties. Knots or the encapsulated branches are the most important factor in the grading of wood. Therefore, the objectives of this research are: detection of knots by non-destructive methods, measuring the dynamic modulus of elasticity of beech log using stress waves, and the effect of knot size on the speed of stress waves Subsequently, the value of dynamic modulus of elasticity.Materials and methods: The studied area of Shafarood series 11, which is located in the southern part of the Shafarood watershed, starts at an altitude of 500 meters and continues up to an altitude of 1650 meters. From this area, Five number of beech trees were cut and divided into three equal parts of three meters by transverse cutting, and according to the size of the knots, the properties of density, stress waves velocity Subsequently, the dynamic modulus of elasticity were measured. From the tangential image of the external indicator and the radial image of the internal indicator by using the Digimizer image4 software, the characteristics of each knot such as the diameter and angle of the knot were measured. For non-destructive detection of beech tree knot, ultrasonic tomography, stress wave velocity and CT scan methods were used. In the stress waves velocity method, a Fakopp microsecond timer device was used to measure the time of stress waves velocity. In the radiographic method as well to prepare CT scan images, A digital ground column device with two detectors made in France belonging to a medical clinic was used. To measure the density, 30 cylindrical stems with knots of small, medium and large classes were used, and according to the relationship between density and stress wave velocity, the value of dynamic elasticity modulus was calculated and evaluated. The diameter of the knot along the length of the stem, the density and the dynamic modulus of elasticity of the beech tree stem were measured. To analyze the data at the 95% confidence level, the one-way Anova test was used, and to determine the normality of the data and the homogeneity of the variance, the Kalmograph Smirnov and Leven tests were used. To compare the means, Tukey's test was used by using Spss software.Results: In the detection of beech tree knot with the three mentioned non-destructive methods, the results show the existence of limitations in each method. As the ultrasonic tomography is not able to detect knots inside the beech tree trunk and the stress wave method also does not detect very small knots. The accuracy of the CT scan method in detecting the knot is high, but the cost of its detection is high. According to the growth stages of the beech tree, factors such as growth speed, branch encapsulation speed and natural pruning are different. The origin of the branch is pith of the stem. As a result, the number and size of the created knots are different along the tree. Therefore, most of the small knots are created in the main trunk of the tree. The diameter of the knot has also increased with the increase in the height of the stem. The knot has increased the density. The density results have shown that the samples with large, medium and small knots have significant differences. Considering that the ultrasonic tomography method is based on the reduction of density, it is not able to detect the knot. But in the radiography method, the parts with higher density are seen in light color and the parts with lower density are seen in darker color. The size of the knot is effective on reducing the speed of stress waves and thus reducing the dynamic modulus of elasticity of wood. In comparison with the samples without knots, the samples with small, medium and large knots reduce the modulus of elasticity by 20%, 50% and 70% respectively.Conclusion: in general, among the non-destructive methods, only the CT scan method is able to detect small knots and evaluate the clear wood and defects. In comparison with the control sample (without knots), with increasing the size of the knot, the value of the density increases and the stress wave velocity decreases Subsequently, the dynamic elasticity modulus of the samples decreases.

Research Paper Wood Modification and Wood Preservation

An Investigation into the Characterization of the painted wooden Shir-Sar of Taqavi house in Gorgan

Yaser Hamzavi; danial harandi; Fathollah Niazi; Seyyed Mohsen Haji Seyyed Javadi

Volume 39, Issue 3 , October 2024, Pages 213-235

https://doi.org/10.22092/ijwpr.2024.365427.1772

Abstract

Background and objectives: Painting on wood became popular in Iran during the Safavid period and reached its peak during the Zand and Qajar periods. The art of painting and writing inscriptions on wood as one of the unique arrays in Iran has been forgotten and their technical and pathological studies ... Read More Background and objectives: Painting on wood became popular in Iran during the Safavid period and reached its peak during the Zand and Qajar periods. The art of painting and writing inscriptions on wood as one of the unique arrays in Iran has been forgotten and their technical and pathological studies will greatly help to preserve and perpetuate such works. Preservation of wood in historical buildings, where color arrays are also applied, is a complex task. The challenge of this work is related to the multiple material characteristics of the work, the type of interventions and the selection of protective chemicals that should be considered in these works. In fact, by fully understanding the work, it is possible to provide a protection solution for it. The purpose of this article is to know the materials, structure and damage of the different layers of the historical headstones of the Taqvi House in Gorgan.Methodology: The wooden lion heads of the Taqvi House in Gorgan, which have written inscriptions along with plant motifs and frames, are the study samples of the current research. The type and amount of the sample was chosen according to the existing uncertainties as well as the test method. In total, four wood samples and four paint samples were prepared. For the technical study of these works, transmission microscope, Dino-Lite plus digital microscope, scanning electron microscope (SEM) equipped with EDS detector were used. Also, under standard laboratory conditions, mushroom cultivation and wood acidity were measured.Results: The black spots in the examination with a digital microscope indicate the presence and growth of biological factors on the surface of wood, which were sampled in a part of them to cultivate and identify the fungi. Initial observations with a digital microscope indicate the destruction of wood components caused by biological factors and the reduction of wood strength and cohesion. In the first investigation, according to the cross-sections of all the samples (three samples), it was found that the samples are broad-leaved woods. The vessels are evenly distributed. In the tangential section, single-celled and multi-celled wood rays can be seen, the width of which reaches about 25 cells. The size of the vessels is almost the same and of a homogeneous and scattered type of vessel. In this sample, two to four vessels are stuck together. The average size of the vessels was measured to be 59 micrometers. Also, the frequency of vessels per square millimeter was calculated to be 130 vessels per millimeter on average. In two samples 2021.G.T.3 and 2021.G.T.8, the vessels are heterogeneous, separated and their cross section is relatively round. Heterogeneous holes and part of the aperture can be seen and some of them are tiled. The diameter of the vessels is specific from spring and summer wood. In the tangential section, single-celled or multi-celled wood rays are observed. In the continuation of the studies, the study samples were examined with a scanning electron microscope with different magnifications. The cell wall in a sample is weakened and is collapsing. Also, the growth of fungi can be clearly seen among the wooden structure. In the other two samples, the cellulosic walls are severely damaged and we see dissociation and rupture between the cellulosic layers.Conclusion:The results of this study showed that the wood used for historical lion heads is beech and mazo wood. Also, fungi such as Aspergillus terius, Alternaria, Aspergillus niger and Cladosporium were identified in the wood structure. In the following, the destruction of the cell wall and the decay of the wood structure were identified. Also, azure blue, syringe red, white flowers, as well as a mixture of carbon black and iron black colors have been used on historical wood as patterns and writings. This study can be very important for the proper preservation of historical wooden works of Gorgan region.

Research Paper Wood Modification and Wood Preservation

Effect of thermo-oil process on biological, physical and mechanical performance of produced thermo wood

Hamid reza Zarey; Reza Hajihassani; seyedeh masoomeh; Kamyar Salehi

Volume 39, Issue 3 , October 2024, Pages 236-252

https://doi.org/10.22092/ijwpr.2024.366260.1776

Abstract

Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional ... Read More Background and Objectives: Wood has some limitations in properties and applications due to its natural nature, which need to be modified. Wood modification is usually done with different aims and methods. One of the wood modification methods is thermal treatments in order to improvement of dimensional stability and biological resistance. But, it is surely affected on physical and mechanical properties of wood. Wood thermal modification in presence of oxygen causes the oxidation of its chemical structure which leads to decrement of physical and mechanical properties. Therefore, elimination of oxygen in thermal modification can reduce its destructive effects. In current study, the effect of thermo-oil process on the function of white rot fungus has been investigated. Moreover, the effect of this process on engineering properties of birch and pine wood species was evaluated.Methodology: In this study, two wood species of birch (Betula sp.) and pine (Pinus sp.) cut into the desired timbers. Heat treatment of the prepared timbers was carried out in a cylinder which equipped to the pressure and vacuum system. Also, industrial recycled oil was used for heat treatment of the timbers. The temperature and time treatment were considered 195 °C and 5 hours, respectively. At the end of the process, the used oil was drained into the oil storage tank and the timbers were removed from the cylinder after applying vacuum. In order to investigation of biological resistance as well as physical and mechanical properties (water absorption and swelling, density, mass loss, bending strength, compression strength parallel to the grain and impact strength) test specimens were prepared from the treated and control timbers based on the standard. The SPSS software was used for statistical analysis. The results were statistically analyzed based on a One-Way ANOVA method.Results: Results revealed that thermo-oil treatment can reduce the functionality of white rot fungus and also its efficiency on physical and mechanical properties of both wood species. Moreover, the results showed that this process improved the physical properties and reduced the mechanical properties, except compression strength parallel to the grain.Conclusion: Thermo-oil treatment at high temperature causes structural changes of wood and affects its physical and mechanical properties. Also, the structural changes caused by heat treatment can be an effective and inhibiting factor to functionality of white rot fungus on physical and mechanical properties of wood.

Research Paper Chemical conversion

Identification and comparison of Heavy Metals in the Wood, Bark and Leaves of Planted Plane Tree and Eldar Pine by Using Flame Atomic Absorption Spectroscopic Method

Ramin Vaysi

Volume 39, Issue 3 , October 2024, Pages 253-267

https://doi.org/10.22092/ijwpr.2024.365063.1769

Abstract

Background and aim: Every year, large amounts of species adapted to the semi-arid environment of Tehran planted. Meanwhile, planted plane tree (Platanus orientalis) and eldar pine (Pinus Halepensis var. Eldarica) tree in Tehran, in addition to creating a green and lively urban space, can also play a ... Read More Background and aim: Every year, large amounts of species adapted to the semi-arid environment of Tehran planted. Meanwhile, planted plane tree (Platanus orientalis) and eldar pine (Pinus Halepensis var. Eldarica) tree in Tehran, in addition to creating a green and lively urban space, can also play a big role in absorbing heavy metals and components in the polluted air of Tehran. This study and it aim was accomplished on identification and comparison of the heavy metals in the wood, bark and leaves of planted plane tree and eldar pine tree by using flame atomic absorption method.Materials and methods: In this study, 20 separate test samples of leaves, wood, and bark of planted elder pine and plane tree were randomly selected from the 4th district of Tehran. According to the TAPPI standard tests, the leaf flour, wood and bark of the samples and their ash percentage were measured. Then with the help of 63% nitric acid and for one hour, the solution containing heavy metal was separated from the ash. In this research, atomic absorption spectrophotometer was used to determine the type and percentage of metal ions absorbed in the wood, bark and leaves of plane tree and eldar pine tree.Results: The results showed that the most ash was found in plane tree bark and the least in plane tree wood. The highest amount of iron ion absorption was found in plane tree leaves, while the lowest amount of iron ion absorption was found in plane tree wood. The amount of iron ion absorption in eldar pine bark is more than its wood and leaves and in oriental plane leaves is more than its wood and bark. The highest amount of potassium ion absorption was observed in eldar pine leaves and the lowest was in eldar pine bark. The amount of potassium ion absorption in eldar pine leaves was higher than its wood and bark, and in plane tree, bark is higher than its wood and leaves. In addition, the absorption of potassium ion is more in plane tree than in eldar pine. The highest amount of copper ion absorption was observed in eldar pine leaves and the lowest amount was observed in plane tree wood. The rate of absorption of copper ions in leaves is higher than the bark and wood of both species. In addition, the absorption of copper ions in eldar pine is more than that of plane tree. The highest amount of lead ion absorption was observed in the bark of eldar pine and the lowest amount was observed in plane tree and eldar pine wood. The amount of lead ion absorption in the bark was more than in the leaves of both species and in eldar pine was more than in plane tree. The highest amount of zinc ion absorption was found in oriental plant leaves and the least in oriental plant wood. The rate of absorption of zinc ions in the bark of eldar pine is more than its leaves and wood and in oriental plant leaves is more than its bark and wood. The highest amount of nickel ion absorption was found in plane tree and elder pine leaves and the lowest in oriental plant wood. The rate of absorption of nickel ions in oriental plant and eldar pine leaves is higher than in their bark and wood. In addition, between the two species, the rate of absorption of nickel ions in eldar pine is higher than that of plane tree.Conclusion: So that, the results showed that the leaves and bark of both species have a great role in the absorption of heavy metal in the air. In addition, the importance of the eldar pine species in absorbing heavy metal such as nickel, zinc, lead, iron and copper is more than the plantain species due to its evergreen nature. Eldar pine and plane tree wood showed the least importance in absorbing heavy metal. While the importance of bark in absorbing lead is the highest. In other words, in urban areas like Tehran, where air pollution is very important, planting eldar pine species seems to be more effective than plane tree.

Pulp and paper

Identify the Chemical Composition of Tobacco Stem Wood Extractives (Nicotiana tabacum L. 'Coker 347') by Gas Chromatography- Mass Spectrometry

Seyyed Peyman Hashemi Beygzadmahalleh; Seyyed Pedram Hashemi Beygzadmahalleh; Asghar Tabei

Volume 29, SPRING 1 , May 2014, , Pages 66-57

https://doi.org/10.22092/ijwpr.2014.4907

Abstract

Tobacco (Nicotianan tabacum) and an old industrial plant in the north, Iran to supply tobacco leaf to produce significant amounts of stem tobacco cultivation and the annual production is in the north of the country. In this research stems of tobacco variety Coker 347 randomly Gilan district, city of ... Read More

Composite wood products

Investigation on the possibility of oriented strand board (OSB) production from hornbeam wood

Abbas Tamjidi; Mohamad Mehdi Faezipour; Habibollah Khademi Eslam; Ghanbar Ebrahimi; Kazem DoosthoseinI

Volume 34, Issue 1 , April 2019, , Pages 140-156

https://doi.org/10.22092/ijwpr.2019.125254.1523

Abstract

DOR:98.1000/1735-0913.1398.34.140.66.1.9.1586 In this study, the possibility of three-layered oriented strand board production from hornbeam (Carpinus betulus L.) wood was evaluated. Two levels of press time (6 and 8 minutes) and three levels of press temperature (180˚C, 200˚C and 220˚C) were applied ... Read More

Dielectric properties of oil impregnated kraft and soda pulps

kezhal Moradyan Gilan; Mohammad Azad fallah; Amir abbas Shayghani akmal; Ali Abdolkhani

Volume 28, Summer 2 , June 2013, , Pages 329-340

https://doi.org/10.22092/ijwpr.2013.2937

Abstract

This research was carried out with the aim of determining dielectric properties of bagasse unbleached soda pulp, long fiber kraft pulp and a mixture of both (20% kraft + 80% bagasse soda).The hand-sheets with 60 g/m2 basis weight were made after adjusting the freeness of pulps at levels of 200 ± ... Read More

Chemical conversion

Morphological Characteristics and Chemical Composition of Grapevine Branches (Vitis vinifera spp.) Grown in Astara

Seyyed Pedram Hashemi Beygzadmahalleh; Seyyed Peyman Hashemi Beygzadmahalleh; Asghar Tabei

Volume 30, WINTER 4 , December 2015, , Pages 525-537

https://doi.org/10.22092/ijwpr.2015.102670

Abstract

This study has been conducted to determine morphological characteristics of fibers and amount of chemical components of grapevine branches cultivated in Astara in province of Guilan. For this purpose the number of 53 branches, with same size and diameter, were cut from some grapevine and sent to laboratory ... Read More

Pulp and paper

Use of Central Composite Design for Optimization of ultrasonic pre-treatment parameters on chemical deinking of old newspaper

Seyed Hassan Sharifi; nouredin Nazarnezhad

Volume 33, Issue 4 , February 2019, , Pages 489-500

https://doi.org/10.22092/ijwpr.2018.122366.1480

Abstract

To reuse recycled cellulosic fibers in paper production, contaminated particles and other impurities of the fibers can be greatly removed using a de-inking stage which is considered as a supplementary step in waste paper recycling technology. The effect of using ultrasonic pretreatment on the deinking ... Read More

Public Titles

Articles ready for publication

Articles in Press, Accepted Manuscript, Available Online from 01 October 2024

https://doi.org/10.22092/ijwpr.2024.132082

Abstract

Public Titles

Research Paper Pulp and paper

Immersion of paper in emulsified beeswax by ultrasonic method and its effect on paper properties

moghadase akbari; Elyas Afra; Mohammadreza Dehghani Firouzabadi; Seyed Majid Zabihzadeh

Articles in Press, Accepted Manuscript, Available Online from 18 August 2024

https://doi.org/10.22092/ijwpr.2024.366132.1775

Abstract

Background and Objectives: Plastic packaging is considered one of the most important sources of environmental problems due to its slow decomposition. To address this issue, biomaterials have garnered attention for their quick decomposition and renewability. In this context, the use of cellulose fibers ... Read More Background and Objectives: Plastic packaging is considered one of the most important sources of environmental problems due to its slow decomposition. To address this issue, biomaterials have garnered attention for their quick decomposition and renewability. In this context, the use of cellulose fibers in packaging is preferred over plastic. However, the main challenge of using cellulose fibers in packaging production is their poor water resistance. This issue can be improved with a suitable bio-coating, which has inspired the current study. The aim of this study was to use a simple method to prepare hydrophobic paper that is environmentally friendly with a biopolymer.Methodology: The raw material used to make handsheets was bleached softwood Kraft pulp from the Pars paper mill. The Canadian Standard Freeness (CSF) of refined paper decreased from 750 ml CSF to 350 ml CSF. To enhance strength properties, the fibers were treated with carboxymethylcellulose (CMC) in the presence of electrolyte (CaCl2). A suspension of untreated (70%) (LF) and CMC-treated (30%) cellulose fibers was used to make handsheet paper (MLF) with a grammage of 60 g/m2. To prepare the emulsion, beeswax was melted in hot water at different concentrations (1, 5, 10, 15, and 20%), then dispersed in water using ultrasound for 9 minutes with an amplitude of 100. The paper was air-dried, immersed in different concentrations of beeswax emulsion, and then heat-treated at various temperatures (25, 60, 70, 80, and 90 ⁰C). The effect of thermal treatment on the efficiency of beeswax was examined by measuring water absorbency time and water contact angle for all treatments, with 70 ⁰C identified as the optimal temperature. The next step is to evaluate the effect of different concentrations of beeswax on properties such as water absorption (cobb), thickness, grammage, tensile strength index, brightness, and opacity.Results: Compared to untreated paper, the water absorbency time and water contact angle of all paper treated with different concentrations of beeswax at various temperatures (25, 60, 70, 80, and 90 ⁰C) increased significantly. The contact angle of handsheets treated with beeswax increased significantly with the temperature of thermal treatment. The highest water contact angle was achieved with handsheets immersed in 20% beeswax and heat-treated at 70 ⁰C. However, further increases in temperature beyond 70 ⁰C did not significantly affect the water contact angle of the paper samples. The water absorption in LF and MLF papers was 65.96 g/m2 and 7.96 g/m2, respectively. Treatment with beeswax reduced the water absorption rate compared to the control treatment at all concentrations. Paper coating increased the thickness and grammage of the paper, which increased with higher concentrations of beeswax emulsion. The tensile strength index increased after using modified fibers with CMC compared to LF paper, but coating with beeswax emulsion decreased the tensile strength index of the paper. MLF treatment and beeswax-coated paper had higher brightness compared to LF paper. Immersion in beeswax slightly decreased opacity, but this change was not statistically significant.Conclusion: The results indicate that the barrier characteristics in samples covered with beeswax improved compared to the blank sample. The study demonstrates the efficient, simple, and cost-effective production of hydrophobic paper as a biodegradable material. A key advantage of this method is the absence of chemicals containing flora or organic solvents in the preparation, making it suitable for industrial applications and meeting the requirements for sustainable development through the use of green ingredients.

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Composite Wood Products Composite wood products

Investigating the physical and mechanical properties of single-layer particleboard from a combination of Prosopis cineraria and industrial wood particles

vahid vaziri; Mohamad Noorirad; hedayatolah aminian; loya jamalirad

Articles in Press, Accepted Manuscript, Available Online from 25 September 2024

https://doi.org/10.22092/ijwpr.2024.365781.1773

Abstract

Background and objectives: Many studies have been conducted on the use of cellulosic resources to provide portion of raw materials for wood and paper industries. Waste branches for some species such as palm and prosopis in southern parts of country can be a solution for deficiency of raw material in ... Read More Background and objectives: Many studies have been conducted on the use of cellulosic resources to provide portion of raw materials for wood and paper industries. Waste branches for some species such as palm and prosopis in southern parts of country can be a solution for deficiency of raw material in wood and paper industries. This study investigated the possibility of using a combination of prosopis and industrial wood particles to produce particleboard with acceptable physical and mechanical properties.Methodology: The variables in this study were the ratio of Prosopis cineraria to industrial wood particles at four levels (0:100, 15:85, 30:70, 45:55) and urea formaldehyde resin at two levels (10 and 12 percent). Industrial wood particles from Sanate Choube Shomal Company and prosopis particles were obtained from the province of Sistan and Baluchistan. Ammonium chloride as a hardener was used at 2 percent of the dry weight of the adhesive. After mixing raw material, the mat was placed under hot pressing at a temperature of 170 ˚C for 6 minutes. After the manufacture of the single-layer particleboard, the physical and mechanical properties of the boards were analyzed by a factorial test in a completely randomized design with a confidence level of 5 %.Results: The results showed that the physical and mechanical properties of the panels decreased as the percentage of mixture prosopis particles increased. So that, panels containing 45% prosopis particles and 10% urea-formaldehyde resin had the lowest mechanical properties, while panels containing 12% urea-formaldehyde resin without prosopis particles had the best mechanical properties. Panels containing 45% prosopis particles and 12% urea-formaldehyde resin had the lowest water absorption and thickness swelling, while panels containing 10% urea-formaldehyde resin without prosopis particles had the highest.Conclusion: According to the results of this study, there was usability of boards with 15% prosopis particles and 10% resin for Type P1 boards and the boards with 15% prosopis particles and 12% resin for Type P2 boards.Background and objectives: Many studies have been conducted on the use of cellulosic resources to provide portion of raw materials for wood and paper industries. Waste branches for some species such as palm and prosopis in southern parts of country can be a solution for deficiency of raw material in wood and paper industries. This study investigated the possibility of using a combination of prosopis and industrial wood particles to produce particleboard with acceptable physical and mechanical properties.Results: The results showed that the physical and mechanical properties of the panels decreased as the percentage of mixture prosopis particles increased. So that, panels containing 45% prosopis particles and 10% urea-formaldehyde resin had the lowest mechanical properties, while panels containing 12% urea-formaldehyde resin without prosopis particles had the best mechanical properties. Panels containing 45% prosopis particles and 12% urea-formaldehyde resin had the lowest water absorption and thickness swelling, while panels containing 10% urea-formaldehyde resin without prosopis particles had the highest.rosopis particles and 10% urea-formaldehyde resin had the lowest mechanical properties, while panels containing 12% urea-formaldehyde resin without prosopis particles had the best mechanical properties. Panels containing 45% prosopis particles and 1

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Management and Economics Wood Management and Economics wood

Investigating the relationship between investment strategies, resilience and financial knowledge on the production growth of wooden furniture industry in the post-Corona era: Moderating impact of government support

Hamed Ahmadi; Ajang Tajdini; Shademan Pourmousa; amir lashgari; Mehran Roohnia

Articles in Press, Accepted Manuscript, Available Online from 25 September 2024

https://doi.org/10.22092/ijwpr.2024.366558.1777

Abstract

Background and Objectives: The Covid-19 pandemic caused serious challenges to various industries of wooden products in various aspects such as access to raw material, supply chain, production and sales volume of product and even customer preferences. Therefore, this study aims to investigate the mediating ... Read More Background and Objectives: The Covid-19 pandemic caused serious challenges to various industries of wooden products in various aspects such as access to raw material, supply chain, production and sales volume of product and even customer preferences. Therefore, this study aims to investigate the mediating role of government support in relation to revising some adopted policies such as investment strategies, creating resilience in industries and improving financial knowledge of managers of these industries in order to increase production of various wooden furniture products in the post-corona era was done.Methodology: In terms of its nature, this research is fundamental-applied and in terms of the type of research, it is a part of mixed research including quantitative and qualitative variables.The study population consisted of 180 managers of home and office furniture manufacturing companies based in Tehran and Alborz provinces, from which 120 were selected through the Cochran formula. Field-library methods are used to collect preliminary information as needed, the main tool for collecting information for this research is a questionnaire approved by academic experts. The used questionnaire includes 22 questions related to research variables, including resilience, government support as a moderating variable, investment strategies, financial knowledge and production growth. Also, the scale used is a 5-point Likert scale. In this research, Cronbach's alpha coefficient, composite reliability and extracted average variance were used to determine the reliability and convergent validity of the questionnaire. In order to analyze the internal structure of the questionnaire and discover the constituent factors of each structure or variable, the confirmatory factor analysis tool was used. Also, to check and analyze the data, descriptive and inferential statistics were used using SPSS software, and to check the relationships between variables, structural equation method based on the use of Smart-Pls software was used.Results: The results of correlation between the variables show that at a significance level of 1%, the highest correlation is between financial knowledge variables with investment strategies, and the lowest correlation is between government support variables with production growth. Also, the reliability check of the questionnaire shows that there is reliability and convergent validity in the questions. The results of examining the measurement model using confirmatory factor analysis show that the items of the model are correctly defined and it is not recommended to remove any of them, because the values of the factor loadings are higher than the minimum acceptable value, i.e. 0.3. This study showed that there is a positive and significant relationship between investment strategies, resilience and financial knowledge as independent variables and positive growth as a dependent variable. Research findings show that the government support component is also related to production growth. It has a positive and significant relationship. In relation to the role of government support as a mediating variable in the relationship between investment strategies, resilience and financial knowledge on production growth of wooden furniture industry, the results show an effective relationship. In all these research hypotheses, the significance level of the p-value test is less than 5% and the T value is outside the range (1.96, -1.96), so it is significant with a 95% confidence factor.Conclusion: The results of this research revealed that in the post-corona era, wooden furniture industry may face new developments and changes. These changes can include changes in the needs and tastes of customers, the process of marketing and selling products, the use of environmentally friendly products, changes in the structure of companies and the necessity of creating industrial holdings, the necessity of using new technologies in production of various products in furniture industry and decoration, paying more attention to firm's internal structures to increase the level of resilience, using managers with extensive financial knowledge to deal with fluctuations of firm's financial assets. Also, in the post-corona era, government support for wooden furniture industries can play an important role in impact of investment strategies, resilience and financial knowledge on production growth of these industries.

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Composite Wood Products Composite wood products

Glass beads and shell on the physical and mechanical properties of polymer matrix nanocomposites reinforced with glass fibers and beech wood flour

Arash Farajpour Roudsari; SEPIDEH SASANIAN; Asghar Tabei

Articles in Press, Accepted Manuscript, Available Online from 23 November 2024

https://doi.org/10.22092/ijwpr.2024.366849.1780

Abstract

Background and Objective: In the present era, technological advancement depends on the progress made in the field of materials. The production of composites is a significant step towards the evolution of engineering materials. By physically combining two or more materials, not only is a lighter and stronger ... Read More Background and Objective: In the present era, technological advancement depends on the progress made in the field of materials. The production of composites is a significant step towards the evolution of engineering materials. By physically combining two or more materials, not only is a lighter and stronger material obtained, but it also replaces traditional materials. This research aims to compare the mechanical and physical strength of composites coated with glass beads (small glass beads) and shells, with each other, and to select the best sample with lighter specific weight, better strength, and easier installation for building facades. Materials and Methods: The samples were prepared using materials such as beech wood flour, E-grade glass fibers, ortho unsaturated polyester resin matrix, montmorillonite K10 nanoclay, MEPK, 10% cobalt as a constant factor, Caspian Sea rolling shell (Cerastoderma glaucum), and glass beads as a variable factor, using the hand lay-up method. Variable percentages of glass beads and shells, or a combination of both, were used on the composite as a gel coat. Fifteen composite blocks with dimensions of 0.2*0.3*0.007 cubic meters were prepared. The excess edges were then sanded. The blocks were placed in an oven at 120 degrees for 2 hours, and after cooling, they were weighed and their dimensions measured. They were cut to the required sizes, and necessary tests to measure physical and mechanical properties such as water absorption, thickness swelling, bending, tension, impact, and abrasion were conducted on the samples based on ASTM standards with three repetitions. Finally, the specific weight was compared according to national building regulations. For data analysis, the SAS9.6 method was used. The validity and reliability of the test were calculated with 99% accuracy based on the test data and reported as an analysis of variance table using SAS software .Results: The findings of this research showed that the initial composite coating made from a combination of nanoclay, beech wood flour, glass fibers, and resin with 30% glass beads increased the composite’s impact resistance. The more glass beads were added to the coating, the higher the impact resistance of the composite. With a 30% coating of Caspian Sea rolling shell on the composite surface, the composite’s resistance to bending and tension increased compared to the control sample. The abrasion rate in composites prepared with 30% glass beads and 30% shell was lower after 200 cycles of abrasion compared to other samples. The thickness swelling rate after 48 hours of immersion in water was zero. Although the water absorption rate in the samples was very low, it can be said that samples with a higher amount of shell had higher water absorption compared to the control sample. The dimensions of the samples were 0.007*0.2*0.3 cubic meters with a specific weight of 1211.9 kg/m³. The highest specific weight in the treatments was related to the sample treated with a 30% glass bead layer coded G180SH0 (p=1240 kg/m³), and the lowest specific weight was related to the untreated control sample coded G0SH0 (p=1192 kg/m³). Meanwhile, the lowest specific weight of stone used for building facades belongs to quartz (p=2000 kg/m³). Conclusion: Overall, it can be said that the composite prepared with a 30% glass bead coating has better quality in terms of abrasion, impact resistance, strength, and non-water absorption compared to other samples. From the relative comparison of the specific weight of the samples, it can also be inferred that with an increase in specific weight, the resistance to impact and bending increases, as seen in the G180SH0 sample. Ultimately, the research objective of preparing a strong and lightweight composite for building facade applications was achieved. Keywords: Nanocomposite, Hand Lay-Up, Glass Bead, Shellfish, Glass Fiber

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Research Paper Pulp and paper

Preparation of cellulose air filter from bamboo fibers

Zahra Kazemi Karchangi; Noureddin Nazarnezhad; hasan sharifi

Articles in Press, Accepted Manuscript, Available Online from 25 November 2024

https://doi.org/10.22092/ijwpr.2024.366975.1781

Abstract

abstractBackground and purpose: Today, with the rapid development of human society, the pollution of particles matter (PM) in the atmosphere has increased. Suspended particles easily enter the human respiratory system and have serious effects on health, they are considered as one of the critical and ... Read More abstractBackground and purpose: Today, with the rapid development of human society, the pollution of particles matter (PM) in the atmosphere has increased. Suspended particles easily enter the human respiratory system and have serious effects on health, they are considered as one of the critical and risky issues in modern urban societies. Air filters play a key role in reducing the emission of these particles and preventing their harmful effects on human health. Due to the growing importance of air pollution and its harmful effects on human health and the environment, the use of effective and environmentally friendly filters has received more attention. In this regard, natural and biodegradable materials such as bamboo fibers are considered a suitable alternative to synthetic polymer materials in making filters. This research focuses on the preparation and evaluation of cellulose air filter using bamboo fibers to deal with air pollution.Materials and methods: To prepare the filter, bamboo fibers were first pulped through the process of soda anthraquinone with sodium hydroxide 25% of dry weight, pulping time 2 hours and temperature 175 degrees Celsius with 0.2% anthraquinone (AQ), then during D0ED1 sequence was bleached by chlorine dioxide and soda. In the next step, the oxidation process was carried out with 3% hydrogen peroxide, 3% sodium silicate and the ratio of sodium hydroxide to hydrogen peroxide 0.8. Then 3% polyvinyl alcohol was added to the resulting suspension and stirred for 10 minutes with the same retention time for all treatments. The suspension was homogenized with an Ultra Thorax homogenizer and dried in a freeze dryer at -110°C for 72 hours to prepare the cellulose filter.Results: The results showed that oxidation and addition of PVA have a positive effect on the mechanical and structural characteristics of the filter. The tensile strength of filters improved significantly after oxidation and adding PVA and increased from 0.236 Nm/g to 0.528 Nm/g. The amount of porosity and air permeability were also affected by oxidation and PVA addition, after oxidation, the porosity and air permeability increased by increasing the number of carboxyl groups and improving the dispersion of cellulose fibers. While the addition of PVA created strong hydrogen bonds and reduced porosity and air permeability. Electron microscopic images (SEM) also clearly showed the structural changes caused by oxidation. After oxidation and adding PVA, the density of the fiber network increased and improved the uniform dispersion of fibers and created a more coherent structure while small pores between fibers still existed. The specific surface area and the average pore size of the filters were checked using the BET method, which shows that the specific surface area increased in the oxidized and PVA-containing filters, and the pore size was maintained in the nano scale in all filters.Conclusion: These results show that the combination of oxidized bamboo fibers containing PVA leads to the production of efficient air filters with improved characteristics that can help reduce air pollution because these filters are able to prevent the passage of PM suspended particles by having pores at the nanoscale.

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