mona shayestehkia; Habibollah Khademi Eslam; Behzad Baziyar; Hossein Rangavar; Hamid Reza Taghiyari
Abstract
Abstract In this research, the effect of cellulose nanocrystals on the functional properties of wood cement composite panels has been investigated. Variable factors in this research are the percentage of nano in (five levels of 0, 0.1, 0.2, 0.5 and 1%), the weight of cement and also the ratio of mixing ...
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Abstract In this research, the effect of cellulose nanocrystals on the functional properties of wood cement composite panels has been investigated. Variable factors in this research are the percentage of nano in (five levels of 0, 0.1, 0.2, 0.5 and 1%), the weight of cement and also the ratio of mixing wood chips with cement in three levels (1 to 3, 1 To 3.5 and 1 to 4) dry weight of cement. In this research, poplar wood and Portland cement type 2 have been used as fixed agents. In total, 15 treatments and 3 replicates of each treatment were made. Preparation of sample in accordance with the standard (DIN / EN 634) and measurement of physical and mechanical properties including flexural modulus, modulus of elasticity in accordance with the standard (DIN / EN 310), internal adhesion in accordance with the standard (DIN / EN 319), thickness swelling after 2 and 24 hours of immersion in water was performed according to the standard (DIN / EN 317). Increased cellulose nanocrystals improved physical and mechanical strength. SEM microscopic images were taken from the samples to examine the microstructural properties of the composite. In the pictures, it was found that by adding cellulose nanocrystals, we see an improvement in the disintegration of nanocomposite materials and as a result, an increase in mechanical and physical properties
Management and Economics wood
Saeed Khojasteh Khosro; Masoud Taghipour Javy
Abstract
The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% ...
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The main objective of the current study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating onto the fire resistance capability and adhesion strength of coating. The nano wollastonites with the concentrations of 0.5, 1.50, and 2.5 wt% were dispersed into the coating. Ultrasonic device was used to stabilize the nanoparticles into the substrates. The coating process was carried out with and without application of the nanoparticles on the surfaces of spruce and sycamore samples and their properties comprising the fire resistance and the adhesion strength were investigated. The obtained results showed that adding of nano wollastonite to the acrylic coating with the waight percent of 2.5% (w/w) had the significance effect onto the resistance of the samples to fire. In particluar, these effects was observed in cas of the retard time of ignition of the spruce and sycamore samples with the improvement values of 258 and 184 % compared with the control samples, respectively. Furthermore, the investigation of adhesion properties of coatings to the sample surface indicated that the applied nano wollastonites improved these properties of coatings. In case of the adhesion properties, however, the highest value of this properties was observed in the highest content of wollastonite nanoparticles. It should be noted that the performance of nanocomposite coating containing of the 1.5 wt% of nano onto investigated properties was also acceptable.
Composite wood products
Hossein Rangavar; Amir Nourbakhsh; Saeid Haji hatmlo
Abstract
The effects of nano-wollastonite on physical and mechanical properties of wood plastic composites made with dried sunflower stalks and alder wood flour, were studied. Five levels of sunflower stalk flour in ratio of the mass wood dry flour containing 0, 25, 50, 75 and 100 percent and nano-wollastonite ...
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The effects of nano-wollastonite on physical and mechanical properties of wood plastic composites made with dried sunflower stalks and alder wood flour, were studied. Five levels of sunflower stalk flour in ratio of the mass wood dry flour containing 0, 25, 50, 75 and 100 percent and nano-wollastonite Powder in three levels, 3, and 5% were considered as variables of the study. Physical and mechanical properties, perpendicular to the screw strength, bending strength, modulus of elasticity, water absorption and thickness swelling after 2 and 24 soaking hours in water were measured in accordance with the standard DIN- EN. In order to examine the intersection of wood and polymer as well as distribution patterns of nanoparticles in the polymer matrix microscopic photos were taken. The results showed that by increasing of sunflower stalk flour in the mixing with wood flour up to 25% increased resistance to screw withdrawal and up to 50 percent increase in flexural strength and modulus of elasticity of wood-plastic composites, respectively. Sunflower stalk flour mixed with alder wood flour increased water absorption and thickness swelling after 2 and 24 hours immersion in water. The use of nano-wollastonite up 5% in relation to the total mass of all the boards improved the physical and mechanical properties of wood-polymer composite.
Composite wood products
mowhammad madadi; Amir Nourbakhsh
Abstract
AbstractIn this research, utilization of ZnO nanoparticles and eggshell powder on physical and mechanical properties of polypropylene/wood flour composite were investigated. For this purpose, wood flour and polypropylene was mixed at 60 to 40% by weight. Eggshell powder at three levels (0, 5 and 10) ...
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AbstractIn this research, utilization of ZnO nanoparticles and eggshell powder on physical and mechanical properties of polypropylene/wood flour composite were investigated. For this purpose, wood flour and polypropylene was mixed at 60 to 40% by weight. Eggshell powder at three levels (0, 5 and 10) percent and nano ZnO at four levels (0, 1.5, 3 and 5) percent were considered as variable factors. Physical and mechanical properties including water absorption and thickness swelling after 2 and 24 hours immersion in water, flexural strength were measured in accordance with DIN-EN 310-2006 standard, and tensile strength were measured in accordance with ASTM D1037 standard. Scanning electron microscope (SEM) were performed to interpret the results. The results were statistically analyzed using factorial experimental under completely randomized block design and the averages were compared using DMRT. Results showed that increasing the mixing ratio of eggshell powder to wood flour decrease mechanical strengths but were improved in water absorption and thickness swelling after 2 and 24 hrs. Using 1.5% nano zno increased the strength properties to the maximum values and improved physical properties.
Composite wood products
Hossein Rangavar; Abolfazl Kargarfard; Mohammad saleh Hosseini fard
Abstract
In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing ...
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In this study, the effect of type II and III Portland cement and the use of undepithed and depithed sunflower stalks particles (Helianthus Annuus) with percentages of different mixing ratio of the poplar wood particles (Populous alba) with 100:0, 75:25, 50:50, 25:75 and 0:100 respectively in the manufacturing of wood-cement composites were studied. Physical and mechanical properties of boards were measured as the effect of lignocellulosic material (sunflower stalks andpoplar wood) and Portland cement type (II and III) on the cement setting time. The results of the study showed that the lignocellulosic material reduced the hydration reaction and increased cement setting time. In this regard, sunflower stalks particles in comparison with poplar wood particles increased cement setting time intensively. The boards made from type III Portland cement had better mechanical strength and physical properties (water absorption and thickness swelling reduced) than with type II Portland cement. In comparison with poplar wood particles usage, the use of sunflower stalks particles and more amount of it caused to mechanical properties decreases and increased the water absorption and thickness swelling after 2 and 24 h water immersion. Therefore the best characteristics were obtained in boards made from 100 percent poplar wood particles. In other hands, using depithed sunflower stalks particles caused to improved the physical and mechanical characteristics. In general, it can be concluded that 25 percent of depithed sunflower stalks particles relative to poplar wood particles (relative to mass lignocellulosic materials( with type III Portland cement in the manufactured wood-cement boards has suitable physical and mechanical properties for usage of these boards in interior building applications.
Composite wood products
ali hasanpoor tichi; behzad bazyar; Habibalah khademieslam; Mohammad Talaeipoor
Abstract
In this study the possibility of nano- wollastonite usage in three level (0 , 3 and 6 percent per dry weight of cement) and mixture ratios of lingo cellulosic materials to cement in three level 10:90, 20:80 and 30:70 on physical, mechanical and microscopic properties of composite made from kraft fibers ...
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In this study the possibility of nano- wollastonite usage in three level (0 , 3 and 6 percent per dry weight of cement) and mixture ratios of lingo cellulosic materials to cement in three level 10:90, 20:80 and 30:70 on physical, mechanical and microscopic properties of composite made from kraft fibers was investigated. There were three replicatesfor each treatment and 27 experimental boards were manufactured totally. Specimens were prepared according to DIN- EN- 634 standard to measure mechanical and physical properties. Mechanical and physical properties including compression strength, interior bonding (IB), thickness swelling after 2 and 24 hours immersion into the water and density were measured. Micro- structural properties of composites were evaluated by SEM images.The results showed that compression strength , interior bonding and density increased by higher levels of nano- wollastonite content in the boards. By increasing of nano- wollastonite, dimensional stability was significantly improved in comparison to the control boards. SEM images showed the improvement of micro- structural boards by increasing the nano- wollastonite content.
Composite wood products
Taherh Gholipor
Abstract
In this study the effect of type of polymer including polyvinyl chloride and high density polyethylene in production of wood plastic composite by using of canola straw waste in two forms, with and without pith (depithed), in combination with wood flour were investigated. Five levels of lignocellulosic ...
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In this study the effect of type of polymer including polyvinyl chloride and high density polyethylene in production of wood plastic composite by using of canola straw waste in two forms, with and without pith (depithed), in combination with wood flour were investigated. Five levels of lignocellulosic materials were used consisting of 100 % wood flour, 100% canola flour including pith, 100% depithed canola flour, 50% wood flour plus 50% canola flour with pith and 50% wood flour plus 50% depithed canola flour. Physical properties of boards including, thickness swelling and water absorption after 2 and 24 hours immersion in water and mechanical properties such as screw withdrawal strength perpendicular on the surface, flexural strength and modulus of elasticity according to EN were evaluated. The results of this study showed that wood plastic composite made of high density polyethylene had better physical and mechanical properties compared with polyvinyl chloride and using of canola flour combined with wood flour lead to increasing flexural strength and modulus of elasticity, but decreased screw withdrawal strength perpendicular on the surface. Using of lignocellulosic filler material by combining of 50% wood flour plus 50 % depithed canola flour combined with high density polyethylene powder can be produced wood plastic composite board with suitable physical and mechanical properties.
Composite wood products
Hossein Rangavar; Abolfazl Kargarfard; Mohammad Hamedbazzi
Abstract
In this study the effect of adhesive types and coated veneer on the physical and mechanical properties of particleboard were studied. Two types of coating, including natural veneer of beech and artificial veneer of High Paper Lamination (HPL, formica) and three types of adhesive composition including ...
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In this study the effect of adhesive types and coated veneer on the physical and mechanical properties of particleboard were studied. Two types of coating, including natural veneer of beech and artificial veneer of High Paper Lamination (HPL, formica) and three types of adhesive composition including (100 % UF), (15% PVA + 85 % UF) and (25% PVA + 75% UF) were used to stick the veneer on particleboard. Physical and mechanical properties of the boards were evaluated according to the EN and ASTM standards. The results of this study showed that increasing PVA resin mixed with UF adhesive, in natural and artificial veneers covering, improved the physical and mechanical properties of the boards. Also, the results indicate that the beech veneer boards are more adhesive than formica. However, formica coated boards compared with beech veneer boards, showed higher bending strength and higher modulus of elasticity. It is evident that the water absorption and thickness swelling values in formica coating boards were less than the beech veneer. Collectively, for production of wooden furniture such as library shelves and cabinets, formica decorative coatings must be used to improve the bending strength. The formica decorative coatings are high in abrasion resistance and stable in humid environment. To stick formica decorative coatings on particleboards, the recommended mix design is 25% PVA and 75% UF resin.
Composite wood products
Hossein Rangavar
Abstract
One of the major problems in wood gypsum particleboard production, faster hydration and thus reducing its physical and mechanical properties. In order to increase the curing time of gypsum, was used from flour glue in wood gypsum particleboard production by using of canola wastes and poplar particles ...
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One of the major problems in wood gypsum particleboard production, faster hydration and thus reducing its physical and mechanical properties. In order to increase the curing time of gypsum, was used from flour glue in wood gypsum particleboard production by using of canola wastes and poplar particles wood. To assess the time of setting of gypsum, the Vicat Needle was used based on the ASTM C191. For this purpose, pure gypsum paste and the pastes with ratios of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 % flour glue to dried gypsum were settled in the mentioned device, then the setting time was determined. Thus amount 0.1% flour glue was selected on the manufacturing of wood gypsum particleboard. To evaluate the effects of flour glue and canola straw wastes on the physical and mechanical properties wood gypsum particleboard, two levels of flour glue (0 and 0.1 %) compared to the mass of the gypsum and the amount of canola straw wastes in 5 levels including (0, 25, 50, 75 and 100%) compared to the mass of poplar particles wood as a research variable factors were considered. Density of boards was 0.9 gr/cm3 and their thickness was 16 mm. The test specimens were prepared for measuring their physical and mechanical properties according to EN standard. Results obtained showed, flour glue lead to increase in gypsum hydration time and improved all of the physical and mechanical properties of wood gypsum particleboard. Also using of canola stem wastes increased value of water absorption & thickness swelling at 2 and 24 hours immersion. Flexural strength and modulus of elasticity of the boards were increase, up to 25% canola wastes compared with dry mass of poplar particles wood, however internal bond of the boards were decreased by the increasing the amount of the canola wastes.
Composite wood products
Hossein Rangavar; Seid asghar Alavi seresht
Abstract
This research was conducted to investigate the effect of nano-wollastonite and the use of polymers polyvinyl chloride and heavy polyethylene on the fire resistance of particleboard with three layers made of pepper stalk and industrial wood particles. Urea-formaldehyde adhesive with concentration of 12% ...
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This research was conducted to investigate the effect of nano-wollastonite and the use of polymers polyvinyl chloride and heavy polyethylene on the fire resistance of particleboard with three layers made of pepper stalk and industrial wood particles. Urea-formaldehyde adhesive with concentration of 12% containing nanowollastonite with mixing ratio of 10% (based on dry mass of wood material) was used. The board in three levels matched (mixture industrial wood with pepper stalk particles), in the form of three layers, include the core layer pepper stalk particles and the surface layer of industrial wood particles, the core layer industrial wood particles and the surface layer of pepper stalk particles and two levels of heavy polyethylene and polyvinyl chloride polymers and nano in the two levels (with nano and without nano) were considered variable factors. Test specimens for examination of characteristics of fire resistance boards were made to include ignition timing(s), fusion time(s), weight loss(%) and carbonized area(mm2) each in two times of 2 and 30 minutes in accordance with the ISO 11925 standard was prepared and evaluated. The results showed that the use of nano-wollastonite and polyvinyl chloride and heavy polyethylene polymer and the boards were improved fire resistance .In particular, heavy polyethylene polymer has a better effect on the fire resistance of the boards. Three layers boards with industrial wood particles on the surface had a long ignition and fusion time. Moreover, percentage of weight loss and carbonized area in a three layer boards with pepper stalks particles on the surface were low
Composite wood products
Ghoncheh Rassam; Hosein Rangavar; vahid nickhah
Abstract
In this study the effects of aluminum dioxide (Al2O3) and copper oxide (CuO) metallic nanoparticles, on the physical and mechanical properties of medium density fiberboard (density of 0.7 g/cm3) made with mixture of industrial wooden fibers and sunflower plant stalk fibers were studied. Two levels of ...
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In this study the effects of aluminum dioxide (Al2O3) and copper oxide (CuO) metallic nanoparticles, on the physical and mechanical properties of medium density fiberboard (density of 0.7 g/cm3) made with mixture of industrial wooden fibers and sunflower plant stalk fibers were studied. Two levels of raw material including industrial fibers and sunflower stalks fibers, with five levels of mixing ratios (100: 0, 0:100, 50: 50, 25: 75, 75: 25), metallic nanoparticles with concentration of 400 ppm each at two levels of 2 and 4 percent (based on dry fiber weight) were used. Physical and mechanical properties including thickness swelling, water absorption after 2 & 24 hours soaking in water, modulus of rupture, modulus of elasticity of bending and internal bonding of the samples were measured and analyzed statistically. The results showed that higher percentage of nanoparticles and industrial fibers and lower percentage of sunflower stalk fibers increased the modulus of rupture and modulus of elasticity. Applying nano-metal treatment reduced water absorption and thickness swelling after 2 and 24 h soaking in water. In overall, using 4% nano aluminum dioxide and 4% nano copper oxide at all levels of mixing ratios were resulted in producing boards with better properties, comparing to the EN 622-5 standard specifications, which are suitable for interior uses.
Composite wood products
Saeed Khojasteh Khosro; Saeed Khojasteh Khosro; Mohammad Hasan Payan; Seyyed Mehdi Seyydi
Abstract
In the present research improvement of dimensional stability and mechanical properties of gypsum particleboard by using white cement was investigated. In manufacturing gypsum particleboard, Micronize gypsum was used in three levels of 2.5:1, 2.75:1 and 3:1 to dried mass of wooden materials. White cement ...
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In the present research improvement of dimensional stability and mechanical properties of gypsum particleboard by using white cement was investigated. In manufacturing gypsum particleboard, Micronize gypsum was used in three levels of 2.5:1, 2.75:1 and 3:1 to dried mass of wooden materials. White cement was added in 2 levels of 5 and 10% based on oven dried mass of gypsum to reinforce gypsum particleboard properties. Water absorption, thickness swelling after 2 and 24 hours immersion in water, bending strength, modulus of elasticity and internal bond strength were measured. Vicat needle method was used to investigate the effect of adding cement on setting time of gypsum. The results showed that adding 5% cement based on oven dried mass of gypsum, increased setting time and also mechanical properties. Adding cement over than 5% (10%), significantly improved dimensional stability but reduced setting time of gypsum and mechanical properties of the boards. On the other hand, results indicated that using Micronize gypsum to 2.75 times to dried mass of wooden materials, increased bending strength and modulus of elasticity. Increasing gypsum in to 3 times, reduced bending strength and modulus of elasticity, but improved internal bond strength and dimensional stability.
Composite wood products
Hossein Rangavar; Mohammad hassan Payan
Abstract
In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based ...
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In this study sound absorption coefficient and hardness of gypsum particleboard produced with kenaf stalk and nano clay were investigated. Variables in this study were weight ratio of kenaf stalks to poplar wood in three levels (40, 50 and 60 %) and nano clay content (0, 3 and 6%) based on dried mass of wooden particles. Sound absorption coefficient determined according to ISO 10534-1 and hardness was measured in accordance with the ASTM D-1037 standards. The sound absorption coefficient was measured at four frequencies of 250, 500, 1000, and 2000 Hz. The obtained results showed that with increasing frequencies, sound absorption coefficient increased. With increasing ratio of kenaf stalk in boards, hardness decreased, but sound absorption increased. Furthermore, increase in percentage of nano clay used in the boards increased the hardness and reduced the sound absorption in coefficient in gypsum particleboard. Generally, the highest sound absorption coefficient was shown the boards produced with 60% kenaf and without nano clay in frequencies of 2000 Hz.
taherh Gholipour; Hossein Rangavar; Abolfazl Kargarfard
Abstract
In this study, physical and mechanical properties of wood-plastic composite made of Canola stem flour and polypropylene were investigated. Variable factors were four levels of canola stem flour (25, 50, 75 and 100 percent based on the dry weight of the wood flour) with and without pit. The control samples ...
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In this study, physical and mechanical properties of wood-plastic composite made of Canola stem flour and polypropylene were investigated. Variable factors were four levels of canola stem flour (25, 50, 75 and 100 percent based on the dry weight of the wood flour) with and without pit. The control samples were made of only wood flour and polypropylene. Physical and mechanical properties including screw withdrawal strength perpendicular on the surface, flexural strength, modulus of elasticity, water absorption and thickness swelling after 2 and 24 hours immersion in water were measured in accordance with EN standards. Results showed that increasing the mixing ratio of canola stem flour to wood flour up to 25% resulted in increase in screw withdrawal strength perpendicular to the surface. Increasing this factor up to 50% led to increase in MOR and MOE. Thereafter, any increase in the mixture, decreased mechanical strengths. Increasing the mixing ratio of canola stem flour to wood flour resulted in increase in water absorption and thickness swelling after 2 and 24 hrs. The specimens without pit showed lowest amount of water absorption and thickness swelling levels and highest mechanical properties (screw withdrawal resistance, flexural strength and modulus of elasticity).
Hossein Rangavar; Behzad Bazyar; Hamed Akbari
Abstract
Abstract : In this study, the possibility of using Cicer arietinum straw residues for manufacturing three-layer particleboards was studied.The amounts of Cicer arietinum straw in mixture with industrial particles were ( % 25:75),(% 40:60),(% 55:45) respectively.Urea formaldehyde (100%) and Melamin urea ...
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Abstract : In this study, the possibility of using Cicer arietinum straw residues for manufacturing three-layer particleboards was studied.The amounts of Cicer arietinum straw in mixture with industrial particles were ( % 25:75),(% 40:60),(% 55:45) respectively.Urea formaldehyde (100%) and Melamin urea formaldehyde at different ratios of MF / UF were used as binders. The resin were applied at two levls of (% 8,10) in core and two levels of (% 10,12) in surface layers, based on oven dried weight of particles. Mechanical and physical properties of boards ( Modulus of rupture, Modulus of elasticity, Internal bonding and thickness swelling and water absorption after 2, 24 hours soaking in water) were measured and data were analyzed, statistically. The results indicated that increase of Cicer arietinum straw lead to increase of bending strength and Modulus of elasticity. Also the increase of resin content and use of Melamin urea formaldehyde resin caused to improve mechanical and physical properties. In General, the use of Cicer arietinumstraw in mixture with industrial particles up to 55% , and resin content of (10,12%) in core and surface layers, resulted in producing boards with appropriate mechanicals properties which are suitable for interior uses.
Hossein Rangavar; Abdolrasool Oromiehie; Arsalan Safarpour; Taherh Gholipour
Abstract
The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. ...
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The present study investigated the application of recycled polyvinyl chloride (PVC) in wood-plastic composite. Wood flour having the particle size of 150 mesh, was produced from a mixture of different hardwoods and used as filler at three levels of 30, 40, and 50% based on the dry-weight of the composite. Three types of PVC were used as the matrix (100% virgin PVC, 100% recycled PVC, and a mixture of the equal weight of virgin and recycled PVC). Maleic anhydride grafted polypropylene (MAPP) was used as the coupling agent at a fixed dosage of 5% based on the PVC weight. The composite panels were produced using injection molding and the physical and mechanical properties of the final boards were evaluated according to ASTM standard test methods. Results showed that the utilizing the mixture of virgin and recycled PVC increased the bending strength and modulus of elasticity. Water absorption was also increased. However, impact resistance and elongation at yield point were decreased. At higher wood flour content up to 40%, flexural strength was increase indicating that the resin properly encapsulated the wood flour particles and at higher wood flour dosage, elongation and Izod impact resistance was reduced.
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).
