Aliakbar Yazdi meymand; Ali Khaki; mohammad ghofrani
Abstract
Sandwich panels are one of the most advanced forms of composite structures that are widely used. The objective of this study was to investigate the effect of three types of resin: urea formaldehyde (UF), melamine formaldehyde (MF) and the combination of urea formaldehyde + melamine formaldehyde (UF + ...
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Sandwich panels are one of the most advanced forms of composite structures that are widely used. The objective of this study was to investigate the effect of three types of resin: urea formaldehyde (UF), melamine formaldehyde (MF) and the combination of urea formaldehyde + melamine formaldehyde (UF + MF) two core layer densities (400 and 500 kg/m3) on physical and mechanical properties of sandwich panels made of palm leaves waste. Pressure temperature, pressure and time for all panels were 175 °C, 35 kg /cm2 and 9 minutes, respectively. The final thickness of all panels was the same and equal to 25 mm. Physical and mechanical properties include; Water absorption (WA), thickness swelling (TS), modulus of rupture (MOR), modulus of elasticity (MOE), impact bending strength (IBS) and internal bonding (IB) were performed on the samples. The results showed that there was a significant (p<0.05) difference between the values of different treatments at the level of 95%. Physical properties (except thickness swelling) and mechanical properties with a density of 500 kg/m3 improved. The use of MF and UF + MF resins significantly improved the physical and mechanical properties of sandwich panels due to its high adhesive quality.
Mohammad Ghofrani
Abstract
AbstractIn this study, alumina nanoparticles was added to clear varnishes (Sealer, clear, semi-polyester and polyurethane), and changes in adhesion strength on wood specimens of Walnut (Juglans Regia) and spruce (Picea Spp) were studied. The experimental samples were prepared from defect-free woods with ...
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AbstractIn this study, alumina nanoparticles was added to clear varnishes (Sealer, clear, semi-polyester and polyurethane), and changes in adhesion strength on wood specimens of Walnut (Juglans Regia) and spruce (Picea Spp) were studied. The experimental samples were prepared from defect-free woods with size of 300×100×10 mm and dried to 8 % moisture content in air drying and Killen drying, respectively. The samples surfaces finished and the clear varnishes applied on samples surfaces using pneumatic spry gun and the adhesion strength test was done on samples. The result of this study showed that the highest adhesion strength was observed in polyurethane varnishes with 6% alumina nanoparticles in walnut wood, and the lowest adhesion strength observed in cellulosic varnishes (sealer and clear) with 0% nanoparticles in spruce wood. It can be concluded that with the control of nano alumina percentage in varnishes in a defined level, the adhesion strength of the clear varnishes increased. Also, with improvement of varnishes’ adhesion strength on wood surface, the varnishes durability increased, consequently.
mohammad ghofrani; Anooshe Fazeli
Abstract
This study was carried out to investigate the effect of two nominal density levels of 800 kg/m3 and 1100 kg/m3 and two levels of industrial wood to cement ratios of 25:75 and 35:65 on mechanical and physical properties of wood cement composites. Boards were produced and then observed density of boards ...
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This study was carried out to investigate the effect of two nominal density levels of 800 kg/m3 and 1100 kg/m3 and two levels of industrial wood to cement ratios of 25:75 and 35:65 on mechanical and physical properties of wood cement composites. Boards were produced and then observed density of boards were calculated. The experimental boards were subjected to modulus of elasticity and modulus of rupture tests in accordance with EN 310. Internal bonding was evaluated according to EN 319. Water absorption and thickness swelling were evaluated after 2 and 24 hours immersion in water according to EN 317. Fire resistance was evaluated according to ISO 11925. Results indicated that bending properties of the boards, including modulus of elasticity and modulus of rupture, and internal bonding all increased with increase in density. That was attributed to the high compression and improved connection between fiber and cement matrix. Modulus of elasticity increased significantly as cement content was raised. Modulus of rupture values were inversely related to cement content. Increasing wood to cement ratio led to low internal bonding because the low amount of cement can be insufficient to cover the wood particles for effective bonding to resist the tensile forces applied during internal bonding test. As the board density increased, dimensional stability increased. Variations in the wood to cement ratio have been reported to significantly affect the dimensional stability of specimens. Water absorption and thickness swelling increased with the increase in wood to cement ratio. Fire resistance of specimens improved when the board density and cement content increased. All of the mechanical properties of boards produced in this study satisfied the EN 634-2 requirements.
Composite wood products
Behzad Hosseini; mohammad ghofrani; Hamid Reza Taghiyari; Saman Ghahri
Abstract
In this research, Effect of soy flour addition into urea-formaldehyde resin on physical, mechanical properties and formaldehyde emission of plywood was investigated. Soy flour was mixed with urea-formaldehyde adhesive in three levels 5, 10 and 15% (based on dry weight of urea-formaldehyde adhesive) and ...
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In this research, Effect of soy flour addition into urea-formaldehyde resin on physical, mechanical properties and formaldehyde emission of plywood was investigated. Soy flour was mixed with urea-formaldehyde adhesive in three levels 5, 10 and 15% (based on dry weight of urea-formaldehyde adhesive) and three-layer plywood was manufacture from the resultant adhesive and poplar veneer. Properties of manufactured plywood including formaldehyde emission according to EN-717-3 standard, shear strength according to EN-314 standard and water absorption and thickness swelling according to EN-317 standard were investigated. The results indicated that addition of soy flour up to 15% decreased formaldehyde emission up to 29.34% and increased shear strength of panels. Moreover, delamination test (According to ANSI/HPV-HPV1 Standard) presented acceptable results. The results obtained from water absorption and thickness swelling after 2h and 24h showed that addition of soy flour increased the amount of water absorption and thickness swelling. thickness swelling after 2h and 24h showed that addition of soy flour increased the amount of water absorption and thickness swelling.
Composite wood products
Mohammad Ghofrani; ali mohamadi
Abstract
This study investigated the comparative tension and compression strength of detachable edge joints in MDF and particle boards. Five pieces of each samples were provides in L shape with the size of 20*20 cm according to D 1761 ASTM. Fittings were applied in three types: cross, hexagonal shape and plastic ...
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This study investigated the comparative tension and compression strength of detachable edge joints in MDF and particle boards. Five pieces of each samples were provides in L shape with the size of 20*20 cm according to D 1761 ASTM. Fittings were applied in three types: cross, hexagonal shape and plastic fitting with 2 types of counter sink and butt screw were used. The results showed that the highest amount of tension strength was in cross shape metal joints and highest compression strength in hexagonal joints. Also the lowest strength of both tension and compression was observed in plastic joints. According to results, the joints with counter sink screws had higher strength than butt screw, and the failure place in this samples was like crevice in the bottom of boards. The data showed that the tension strength of all three fittings were higher than compression strength. The highest bearing of tension stress was in MDF with glue and dowel, counter sink screw and cross shaped fitting and the lowest was in particle boards without dowel, butt screw and plastic strips. The highest bearing of compression stress was in MDF with glue and dowel joint, hexagonal metal strip and counter sink screw, the lowest was seen in particle board without dowel, butt screw, and plastic strip.
Management and Economics wood
mohamad ghofrani; Zahra Mohammad Moradi
Abstract
Nowadays, Due to the unstable world economy, to survive and create competitiveness in domestic and overseas market, sustainable production and increases in quality and quantity of products is needed, In case of no attention, the possibility of competitiveness in regional and international markets will ...
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Nowadays, Due to the unstable world economy, to survive and create competitiveness in domestic and overseas market, sustainable production and increases in quality and quantity of products is needed, In case of no attention, the possibility of competitiveness in regional and international markets will not occur. Therefore, in this study, with cooperation of experts and industry manufacturers’ expertise determination and ranking of factors affecting classic furniture was determined by using analytical network process and DEAMATEL techniques. 5 main and 17 sub-indexes parameters examined in this study and by using analytical network process the importance of prioritizing criteria was determined and cause and effect relationships between indicators was evaluated by DEAMATEL techniques. The results showed that, the main indicator of production and sales management, quality assurance, design style and creativity have the highest normal weight and the sub-indices of the modernity of machines and technology, reasonable price and Brand longevity respectively, are the three top priorities to impact on the competitiveness of classic furniture.
Mohammad Ghofrani; afrooz ghiyasvand
Abstract
Nowadays, the leading experts of the world’s furniture industry approve the existence and potentials of Iran furniture industry and more importantly, they believe it can advance and grow much more in the future. So, the purpose of this paper is investigating of the domestic living furniture producer’s ...
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Nowadays, the leading experts of the world’s furniture industry approve the existence and potentials of Iran furniture industry and more importantly, they believe it can advance and grow much more in the future. So, the purpose of this paper is investigating of the domestic living furniture producer’s point of view on the way of manufacturing and selling of these products. In this regard, information from aware academic specialists was gathered. Then five indices, affecting the production and sell of furniture, was determined and used in the form of a standard questionnaire. In order to check the validity and reliability of the survey, Cronbach’s alpha coefficient and content validity methods were used, respectedly. Ultimately, rating the indices by Leikert method showed that: customer focus, collaboration with the academics, imported furniture, designing and finally producer’s satisfaction of government and business suporters, respectedly had the most to least degree of importance for domestic living furniture producers to the way they manufacture and sell their furniture products.
Mechanical conversion of wood and wooden fittings
Hamid Reza Taghiyari; Mohammad Ghofrani; Farzad Arbabi ghamsari
Abstract
The present research project was carried out to find out tension-carrying capacity of corner miter V-joints in tensile and compression directions to be compared with those of dovetail joints. Variables included the type of wood-composites to produce the joints (MDF and particleboard), the number of V-nail ...
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The present research project was carried out to find out tension-carrying capacity of corner miter V-joints in tensile and compression directions to be compared with those of dovetail joints. Variables included the type of wood-composites to produce the joints (MDF and particleboard), the number of V-nail in each joint (2, 3, and 4 V-nails), and the height of V-nails (7 and 10 mm). Separate sets of joints were produced with and without polyvinyl acetate resin. Results demonstrated that the tension-carrying capacity under compression tension was significantly higher than those in the tensile tension. Moreover, MDF joints showed higher tension-carrying capacity in comparison to those made from particleboard. Joints with resin were significantly stronger than those without resin. Increase in the number of V-nails resulted in an improvement in the tension-carrying capacity in both directions. Based on the results of the present research project, it was concluded that V-nails are preferred to dovetail joints from different perspectives, including their lower production expenses, lack of need for an extra step to mill the joint so that joint bits be inserted into, fast and easy installation of V-joint in one-step process, as well as higher tension-carrying capacity. Based on the obtained results indicating the maximum tension-carrying capacity of 13.7 MPa and 28 MPa for V-nails without and with adhesive, respectively, it was concluded that 4 V-nails with 10 mm in height in MDF joint-members would be recommended for joints without resin. In case of joints with resin, MDF joint-members with 3 V-nails of 10 mm would provide the highest tension-carrying capacity for craftsmen and producers of furniture and cabinets.
Mechanical conversion of wood and wooden fittings
Mohammad Ghofrani; Zahra Mohammad Moradi; Saeed Khojasteh Khosro
Abstract
In present study the effect of different methods of applying transparent coatings on adhesion strength of coating in Walnut (Juglans regia), Maple (Acer velutinum) and Pine (Pinus eldarica) species was investigated. For this purpose, samples prepared with dimension of 200×100×20 mm and 8% ...
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In present study the effect of different methods of applying transparent coatings on adhesion strength of coating in Walnut (Juglans regia), Maple (Acer velutinum) and Pine (Pinus eldarica) species was investigated. For this purpose, samples prepared with dimension of 200×100×20 mm and 8% moisture content. Samples’ surfaces were sanded with 100, 120 and 180 grate sizes sandpaper significantly. Then after preparation wooden samples with sealer, their surfaces covered with clear and acid catalyzed transparent finish in separate process by using spray gun and applicator. Adhesion strength of coating was measured with Pull-Off method based on ASTM D4541 standard. Fluorescence microscopy test used for investigation coating penetration in spray gun and applicator method. Results showed that the method of applying coating on wooden surfaces has significantly affected adhesion strength, and highest adhesion strength between all samples, observed in samples coated with applicator method. Investigation of coating penetration indicated that applicator method had good penetration in wood substrate in comparison spray gun method. Highest differences in adhesion strength of coating between spray gun and applicator method were observed in Walnut and Maple’s samples. In general, highest adhesion strength of coating was found in Walnut samples covered with acid catalyzed transparent finish by using applicator method.
Management and Economics wood
Mohammad Ghofrani
Abstract
In this study, the effect of heat treatment of Alder (Alnus glutinosa), Poplar (Populus nigra) and Spruce (Picea abies) on adhesion strength of clear and acid catalyzed transparent coating was investigated. For this aim, wooden samples were prepared with dimension of 200×100×18 mm (longitudinal, ...
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In this study, the effect of heat treatment of Alder (Alnus glutinosa), Poplar (Populus nigra) and Spruce (Picea abies) on adhesion strength of clear and acid catalyzed transparent coating was investigated. For this aim, wooden samples were prepared with dimension of 200×100×18 mm (longitudinal, tangential, radial) from sapwood on tangential surface. Samples were kept under heat treatment in oven with 150 and 180˚C temperatures for about 3 hours. After treatment, samples’ surfaces were sanded with 120 and 180 grit size sand paper, respectively. Contact angle of water was measured before and after treatment. Samples’ surfaces were covered with a transparent coat in two separate processes which were clear and acid catalyzed. Adhesion strength of coating measured with Pull Off method according to ASTM D-4541 standards. Results showed that the heat treatment increased contact angle. This increase continues as the heat treatment temperature goes higher and it leads to decrease in wettability of samples’ surfaces. Results also indicated that heat treated of wood had significant effect on adhesion strength of coating. Adhesion strength in control samples was more than heat treated samples. lowest coating strength was observed in samples which were heat treated in 180 ˚C.
Management and Economics wood
shahram tahmasebi; behzad bazyar; habibolah Khademi Islam; mohammad Ghofrani
Abstract
In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used ...
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In this study, structural performance of corner joint reinforced by fiber reinforced polymers (FRP) at the area of maximum tension stress was investigated under diagonal tension loading. Therefore 1 to 3 layers of unidirectional woven Glass, Carbon and Kevlar fibers were used and hand lay-up was done by vinyl ester and epoxy resins. Results of load-displacement curve at yield point exhibited capability of the reinforcing layers in preventing joint opening to some extent under load. However, failure was observed at the joint due to picking fibers from wood surface or members fracture near the interface when loading increased. Since the reinforced zones of the joints by FRP show the maximum shear stress, consequently the separation of fibers from wood surfaces increased at these locations. The adhesion of FRP layers to joint surface was not appropriate due to difficult process of layering at right angle of joints followed by probable formation of air bubbles. The results of assessing FRPs reinforcing behaviour indicated that application of vinyl ester in comparison with epoxy as matrix exhibited better performance. In addition, glass and carbon fibers showed better performance than Kevlar fibers as reinforcing agents.
Management and Economics wood
Saeed Khojasteh Khosro; Mohammad Ghofrani; Morteza Ganjaei sari
Abstract
In this study the effect of adding zinc oxide nanoparticles (ZnO) on color change and adhesion strength of polyurethane clear coat in Elm wood species (Ulmus glabra) investigated. ZnO nanoparticles with concentration of 0, 0.25, 0.50, 1, 1.50 and 2 wt% were dispersed in coating. TEM (Transmission electron ...
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In this study the effect of adding zinc oxide nanoparticles (ZnO) on color change and adhesion strength of polyurethane clear coat in Elm wood species (Ulmus glabra) investigated. ZnO nanoparticles with concentration of 0, 0.25, 0.50, 1, 1.50 and 2 wt% were dispersed in coating. TEM (Transmission electron microscopy) images were used for investigate the dispersion of nanoparticles in coatings matrix. Results of investigate the dispersion of nanoparticles in polyurethane coating indicated that the best dispersion of nanoparticles obtained in coating with 1 wt% nano. Increasing concentration of nanoparticles to 2 wt%, reduced dispersion of nanoparticles and aggregates of nanoparticles observed in coating. Investigation adhesion strength of coating showed that the highest value of adhesion was in nanocomposite coating with 1 wt% nano but increasing nanoparticles more than this content, had negative effect on coating adhesion. Results also revealed that adding ZnO nanoparticles, changed color of samples coated with nanocomposite coating but it was not significant in low content of nanoparticles.
Mechanical conversion of wood and wooden fittings
Mohammad Ghofrani; Mohammad Kahvand; Habib Noori
Abstract
This study was conducted to evaluate stress carrying capacity of miter corner joints fabricated with loose tenon with loose tenon under diagonal tension and compression loading. In this study, tests were carried out to determine the effects of dimension of loose tenon A (3.5 × 1 × 0.8 cm) ...
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This study was conducted to evaluate stress carrying capacity of miter corner joints fabricated with loose tenon with loose tenon under diagonal tension and compression loading. In this study, tests were carried out to determine the effects of dimension of loose tenon A (3.5 × 1 × 0.8 cm) and B (3 × 2 × 0.8 cm), type of adhesives (Polyvinyl acetate (PVA) and polyurethane (PU)) and most commonly used wood species in furniture industry including beech (Fagus orientalis L.) and fir (Abies alba). The results indicate the stress carrying capacity joints under compression is higher compared with that in tension. Stress carrying capacity joints constructed with dimension of loose tenon A was higher than that of those with B. Furthermore, the results have shown that wood species and type of adhesive had significant effect on the stress carrying capacity and performance of joints constructed of Beech wood and PU adhesive were stronger than joints made of Fir wood and PVA adhesive.
Mechanical conversion of wood and wooden fittings
Mohammad Ghofrani; Hossein Hosseinkhani; Habib Rahimi dastjerdi; Saeid Khojasteh khosro; Parviz Amiri
Abstract
The objective of this study was to investigate the influence of hydrothermal treatment of walnut (Juglans regia) and caucasian elm (Zelkova Carpinifolia) wood species on their acoustic properties in radial and tangential directions. For this purpose, specimens were prepared with dimensions of 360 (L) ...
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The objective of this study was to investigate the influence of hydrothermal treatment of walnut (Juglans regia) and caucasian elm (Zelkova Carpinifolia) wood species on their acoustic properties in radial and tangential directions. For this purpose, specimens were prepared with dimensions of 360 (L) ×20 (R) ×20 (T) mm. Heat treatments in water medium were performed at 150ºC for 5 hours. Acoustic properties of specimens (specific modulus of elasticity, damping, acoustical coefficient, acoustical conversion efficiency and wave velocity) measured by free flexural vibration on a free-free bar method. Properties of treated specimens compared with control specimens. Result showed that hydrothermal treatment improved all acoustic properties of specimens. Acoustic properties of radial and tangential surfaces of walnut wood did not show significant difference; while in caucasian elm significant differences obtained between radial and tangential surface properties. Generally, better acoustic properties achieved in tangential direction of heat-treated Caucasian elm species. So, it is recommended as a suitable specimen to be used in making the sound-boards of musical instruments such as Iranian Santour and Xylophones and also resonator boxes.
Management and Economics wood
mohammad ghofrani; vajihe farshchi; majid azizi
Abstract
Nowadays, producers are successful in Of getting profit in more efforts to satisfy our customers in target markets And build customer loyalty to your brand. The aim of this study was to study and identify factors influencing loyalty Customer to the brand in the furniture industry using Group Decision ...
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Nowadays, producers are successful in Of getting profit in more efforts to satisfy our customers in target markets And build customer loyalty to your brand. The aim of this study was to study and identify factors influencing loyalty Customer to the brand in the furniture industry using Group Decision Making method., For the purpose of study and research Been done by others, the factors affecting customer loyalty divided in to 4 main categories and 20 sub-indicators. After getting customer buyer furniture opinions via questionnaire, the priority rates of obtained criteria and sub-criteria were determined by Analytical Hierarchy Process (AHP).The results show that customers Satisfaction and marketing criteria have the highest weighting values at the first level. In addition, among 20 effective sub-criteria, Influence on customer loyalty in the furniture dustry, service quality ,reasonable price ,installment sales, warranty and perceived quality have highest priorities as 0.323, 0.151,0.129, 0.074 and 0.053 weighting values, respectively.
Mohammad Ghofrani; Sakineh Pishan; Aysona Talaei
Abstract
Increasing demand for light and durable materials in home and office furniture requires optimizing the properties of the products used. In this research the effect of skin type and core on mechanical properties of light weight sandwich panel was investigated. The skins were made of MDF with ...
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Increasing demand for light and durable materials in home and office furniture requires optimizing the properties of the products used. In this research the effect of skin type and core on mechanical properties of light weight sandwich panel was investigated. The skins were made of MDF with 3, 6 and 8 mm thickness, particle board with 8 mm thickness, three layer plywood with 3.8 mm thickness and five layers plywood with 7.28mm thickness. The cores of polyurethane foam and honeycomb of kraft paper (3 cm thickness) were used. Mechanical tests including bending strength, modulus of elasticity; impact bending and compression were performed according to DIN and ASTM standards. Result showed that, light sandwich panels made from polyurethane foam core had higher mechanical properties than the light panel made of kraft honeycomb core which indicates that the dense and homogenous structure and better linkage with skin. By increasing the thickness of skin in the samples made from MDF skin, the properties of sandwich panel increased. The best result of mechanical properties was observed in light weight sandwich panel made of plywood skin and polyurethane core.
Mohammad Ghofrani; Habib Nori; Hossein Rangavar
Abstract
In this study we have paid to mechanical strength measurement of redy to assemble joints (RTA). Including metallic angular joint and elite and compere them with fixed joints including wooden dowel twist and biscuit joint in two cut load test, siding, in some fiber board factor with medium ...
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In this study we have paid to mechanical strength measurement of redy to assemble joints (RTA). Including metallic angular joint and elite and compere them with fixed joints including wooden dowel twist and biscuit joint in two cut load test, siding, in some fiber board factor with medium density fiber board(MDF ).According to ASTMD1761 standard testing cases with L-from from two pice of MDF with 20cm*20cm dimensions that are mad in L-form and the repetition that have been taken in cansidration for any maintance is 5 sample.The number of 80 sample that are studied in this field are as follow: fixed joint including wooden dowel joint, granulated with drops of 8mm and 10mm covering by Adhesive PVAc, twist joint with 40mm and 50mm length , wooden Biscuitt joint number 10 coverd with( mixed with )PVAc adhesive and ready to assemble joint including Elite joint reinforcement with dowel with 8mm and 10mm diameter, metallic ready to assemble joint with pin and withont pin, reinforcing with dowel to 8mm and 10mm diameter.In fixed joint for studing the coated effect, we have used plates of MDF with coated and without coated (uncoated). The result of study showed ready to assemble joints with pin is more than ready to assemble angular joints without pin, also ready to assemble joints strength of Elite joints with dowel 10mm is more than fixed joint strength of 8mm dowel. fixed joint strength of 5mm twist with MDF uncoated in both tests in more than strength of uncoated 4cm twist. more upper rang of strength 4cm twist. more upper rang of strength in ready to assemble joints are specified in cut load test siding regular spinous and 10mm dowel. In fixed joints there is more strength in 10mm dowel joints. for ready to assemble joints, pin reciprocal effect and dowel diameter is 87 and 30/8 respectfuly.Acocording to obtained resalts between more better care of two group are intraduced in spinous ready to assemble joints with 8mm dowel (191.61 N ) and l0mm dowel joints (135.14N).
mohammad ghofrani; Habib Nori
Abstract
In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance ...
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In the present study the strength of different kinds of wooden dowels, screws, and ready-to-assemble joints (RTA joints) used in medium density fiberboards (MDF) were assessed and compared for their lateral shear strength. The T-form specimens (20 cm × 8 cm) were comprised of two MDF parts in compliance with ASTM D1761 standard. Five specimens for each treatment were made and a total of 20 treatments were designed; treatments in this study are as follows:Rough as well as smooth dowel joints with 8 and 10 mm diameter, using urea-formaldehyde and poly-vinyl acetate adhesives; Screw joints, sizes 5 and 6, with or without urea-formaldehyde as well as poly-vinyl acetate adhesives; And, different kinds of RTA joints.Results indicate that different kinds of screw joints show the most powerful joints in comparison with other kinds of joints; but there was no significant difference between different kinds of screw joints. Therefore, having economical points of view in mind, screw joints size 5 is recommended to be used without adhesive. The effect of dowel surface as independent variable was statistically significant, while the interaction effect of dowel diameter, adhesive, and quality of dowel surface on lateral shear strength, as well as the independent and interaction effects of two factors of combined wooden dowel along with joint, and adhesive on the strength of RTA joint (that has nuts) were statistically significant.
Physics and Mechanical Wood
Habib Nori; Ahmad Jahan latibari; mohammad ghofrani
Abstract
Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon ...
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Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon 44.9, populous deltoids 69.55, and populous euramerican are investigated. The average fiber length of these three colons were 0.854, 1.148, 1.08 mm. respectively and their average dry specific gravity were 0.386, 0461, and 0.341 g/cm3, and also their average cellulose content were 50.5, 51.5, and 49.5 percent.For Kraft process cooking of the mentioned colons, three cooking time, 1, 2, and 3 hours, 17°C cooking heat, 25% sulfidity, and active alkali at 3 levels, 15, 17.5, and 20% were used. The results show that p. alba, colon 44.9, and p. deltoids colon 69.55 with using 20% A.A and 3 hours cooking time have 53% yield and 18 kappa number.
