جستجوی مقالات مرتبط با کلیدواژه « particleboard » در نشریات گروه « صنایع چوب و کاغذ »

The lack of wood resources on the one hand and the increase in the demand for wood products on the other hand have caused the excessive harvesting of wood and the shortage of wood raw materials. Therefore, alternative materials should be used to solve this problem. But, in addition to providing raw materials, alternative materials must be approved from the economic point of view and the mechanical properties of the boards. Since CZ100 is a crystalline and homogeneous mineral, it is cheap and readily available. It also has high strength, stability, and mechanical resistance. Therefore, the aim of this research is the effect of CZ100 additive on the physical and mechanical properties of particleboard. For this purpose, boards were made with CZ100 additive in proportions (0, 2, 4, 6, 8, and 10%). Then, the mechanical and physical properties of particleboard made with CZ100 additive were measured. The results showed that the mechanical properties of particleboard increased with the addition of the CZ100 additive by up to 6 wt%, and with the addition of the additive, water absorption and thickness shrinkage (2 and 24 hours) decreased significantly. In general, according to the obtained results, the additive CZ100 has a high potential to improve the physical and mechanical properties of particleboard and also due to its low price compared to wood, its use reduces the costs of preparing raw materials.

In this research, the shear strength of joints made of medium-density fiberboard (MDF) and particleboard with screwshas been evaluated. Therefore, T-shaped joints were made from two pieces with a dimensions of 7.5 x 15 cm by one screw as a fastener. The screw was selected as a variable in three levels of diameter: 4.2, 5 (panel screw), and 6 mm (Allen socket head cap screw). The Joints, were tested under shear load in two directions, parallel and perpendicular to the edge of the main member. The loading rate was 5 mm/min. The results have shown that MDF and particleboard have similar performance against shear loading. The screw diameter had a significant effect on the strength of joints in shear loading. Joints made with MDF and particleboard have a better performance against shear load when the load was perpendicular to the edge of the main member. Also, the results have shown that the joints made with 6 mm diameter screws in both MDF and particleboard show more resistance against shear loading. This increase was more noticeable in the case of loading perpendicular to the edge of the main member. The mode of failure results showed that the loading type affected in the failure of specimens. In parallel loading to edge loading internal bounding has been effective, while in perpendicular to edge loading in addition to the internal bounding, surface density has also been effective.

The aim of this study was to investigate the withdrawal resistance of T-shaped joints, shear strength and bending moment capacity in the diagonal tensile loading of L-shaped joints made of wooden biscuits.The type of joint members including medium density fiberboard (MDF) and particleboard and the size of biscuits 10 and 20 (one biscuit per joint) were the variables of this study. After constructing the specimens using polyvinyl acetate (PVAc) adhesive, the withdrawal resistance test of T-shaped joints and shear strength and bending moment capacity tests of L-shaped joints were carried out. The results of analysis of variance showed that the effects of independent variables namely, the composite type (Joint members) and the biscuit size on the the withdrawal resistance was significant in the 95% confidence level, also the effects of these independent variables on the shear strength and the bending moment capacity in diagonal tensile loading of the biscuit joints, was significant in the 95% confidence level. According to the results, T-shaped joints made of wood biscuits of MDF members have a higher withdrawal resistance than joints made of particleboard members. the withdrawal resistance of T-shaped joints made of Biscuit size of 20 was higher than that of joints made of Biscuit size of 10.The Shear strength and bending moment capacity in diagonal tensile loading of L-shaped joints made of MDF members were higher than those made of particleboard members. The L-shaped joints made of biscuit size of 20 showed higher shear strength and bending moment capacity in tensile loading, than joints made of biscuit size of 10. generally, the highest amount of tensile and shear strengths and bending moment capacity in tensile loading were observed in the joints made of MDF and biscuit size of 20.

This study aims to use zeolite as a retarder of particleboards from sugarcane pulp (bagasse). In this study, mechanical properties, physical properties, fire resistance and CIE L * a * b * colorimetric test were investigated. The results of this study showed that the use of zeolite led to an increase in flexural strength, modulus of elasticity and impact resistance of the resulting particleboards. However, the internal adhesion of the resulting particleboard decreased. In addition, the use of zeolite as a flame retardant increased fire resistance. The results of physical properties also showed that zeolite reduced water absorption and thickness swelling in 2 hours of immersion. While water uptake and thickness swelling increased during 24 hours of immersion. The results showed that zeolite caused color change with increasing Δl and finally increased the whiteness and brightness of the surface of the samples. Zeolite reduced the combustion parameters, reduced the mass due to burn and the amount of carbonized surface and significantly increased the ignition time while drastically reduces flame retention and weight loss. In general, according to the measured parameters, the addition of zeolite can be considered as a slowing treatment.

Today, several modeling methods have been used to cost-efficiently predict the physical and mechanical properties of wood-based panel products which in turn reduce the cost of quality control of these products. Two common methods include regression and artificial neural network (ANN). In this study, the possibility of predicting the modulus of rupture (MOR) and modulus of elasticity (MOE) of particleboard by simple and multiple linear regression and ANN based on structural parameters including density in three levels (0.65, 0.7, and 0.75 g/cm3), slenderness ratio of particles in three levels (47, 30, and 13) adhesive percent in three level of (8, 9.5, and 11%) were evaluated. experimental and predicted data were compared with different criteria including mean absolute percentage error (MAPE), mean squared error (MSE) and coefficient of determination (R2). The results revealed that although both multiple linear regression models and artificial neural network were able to predict MOR and MOE values with acceptable accuracy, but ANN model predicted them with higher R2 and lower MAPE than multiple linear regression model. The value of MAPE and R2, for prediction of MOR and MOE by ANN model were 7.72% and 0.77, and 7% and 0.86, respectively. the corresponding value for multiple regression model were 8.3% and 0.738, and 9.06% and 0.783, respectively. These levels of error are industrially and practically satisfactory for the prediction of properties in particleboard.

In order to investigating the usage of wheat straw on particleboard, wheat straw powder was treated with 5% hydroxide sodium for 120 minutes; then, untreated and treated wheat straw powder were mixed with industrial wood chips in five levels of 0:100, 30:70, 40:60, 50:50, 60:40, 10%, and 12% urea formaldehyde resin based on dry weight of raw materials, and 2% ammonium chloride based on dry weight of adhesive to make single layer particleboard. Physical and mechanical properties of produced panels were tested according to EN 326-1 standard. The physical and mechanical properties of panels made from treated wheat straw were significantly better than untreated one, and use of 40% wheat straw powder with alkali treatment ratio to industrial wood chips was shown the best results.

The importance of market concentration for government decisions and policies to regulate the market is inevitable. In this study, market indexes were calculated to identify the market status of particleboard imports and to help industry practitioners to identify the particleboard market and identify production potential. In this study, the market structure was measured using concentration ratios, Herfindahl-Hirschman, Hall Tideman, Comprehensive Industrial Concentration, and Hannah-Kay. The market structure was measured for the period 2010-2019. According to the calculations, the average concentration ratio of the four major exporting countries to Iran for the ten-year period studied was 97.81% of the total import of particle board to the country. They indicates a market with a multilateral monopoly. Other indicators include the Herfindahl-Hirschman index at 5,561, the Hall Tideman index at 0.54, the Comprehensive Industrial Concentration Index at 0.79, and the Hall Tideman Index at α value of 0.6 to 3.12, α value was equal to 1.5, to 2.27 and α value was equal to 2.5 to 2.02. The results have shown that the market situation on the import of paticle board was the multilateral monopoly. The status of this monopoly has fluctuated and changed over the past ten years due to the political and economic decisions of governments and the change in domestic production of particleboard. In this market situation, exporting countries can argue over price and export rates. Turkey, United Arab Emirates, Thailand, Italy and Russia has been Iran's most important trading partner in the particleboard import market during the period under review, with the most imports being indexed to these countries, indicating a multilateral monopoly.

The aim of this investigation was concentrated on the possibilty of untilizing corn cops residues in the production of particleboard. Two press temperatures of 170 and 180 oC, and four ratios of corn cop/poplar wood particles (100/0, 75/25, 50/50 and 25/75) in the corn layer of the boards and 100% poplar wood particles in the surface layer were used. A combination of 16 treatments were reached and three laboratory boards for each treatment were made. Physical and mechanical properties of the boards were measured and statistically analyzed. The grouping of the averages were based on duncan multiple range test. The results indicated that the influence of the press temperature on both modulus of rupture and modulus of elasticity was statistically significante and boards produced applying 170 oC reached higher values. As the ratio of the corn cop particles in the particle mixture in core layer increased, both modulus of rupture and internal bonding deteriorated and the highest value were measured at 50/50 ratio of the particle in the core layer. The Boards which produced applying higher press temperature exhibited hgiher rate of thickness swelling . Lower ratios of the corn cop particle in the mixture of particles in the core layer improved the properties of the boards. So that the ratio of 50/50/ and 25/75 produced lower thickness swelling. The results of this research revealed that eventhough boards produced using corn cop particles did not produce comparable properties to the boards based on poplar particles, but it can be concluded that if 50/50 ratio of particles, press temperature of 170 oC is used for board making, the mechanical properties of the produced boards will meet the requirement of DIN specifications.

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.

The purpose of this study was to use of Hemp stalks in particleboard production. Mixtures of Hemp stalk and Eucalyptus wood at the ratios of 0:100, 50:50, 100:0 were used. Also two resin content of 8 and 10% (based on oven dry particle) and 2 press times of 3 and 4 minutes were employed for the production of laboratory particleboard. Physical and mechanical properties including thickness swelling after 2 and 24 hours soaking in water, modulus of rapture, modulus of elasticity and internal bonding were measured data were statistically analyzed. It was observed that the increase in Hemp stalk particles in the mixture resulted in increasing of bending properties (bending strength and modulus of elasticity) and thickness swelling after 2 and 24 hours water soaking. Also the results showed that increase in Hemp stalk particles in the mixture resulted in reduction of internal bonding. As expected, physical and mechanical properties of particleboard improved with increasing resin content. Modulus of elasticity and thickness swelling after 24 hours water soaking were improved with increasing of press time. In general, comparing the produced board mechanical properties with standard of Iran requirements, the board produced using 100% and 50% Hemp stalk, 8% resin content and 3 minutes press time showed that optimal properties. Although the physical properties of the boards did not meet the standard values, the reason for this could not be due to the lack of use of paraffin.

This study was conducted to evaluate the effects of the penetration depths (8, 11, 14) and material types of spline (high density fiber board (HDF), plywood and hornbeam wood (Carpinus betulus)) composite material types (MDF and particleboard) on bending moment resistance of mitered L-type joints. In this research L-type joints fabricated with spline and PVA adhesive with dimensions 160 × 230 ×16 mm (Length × Width × Thickness respectively). Joints were fabricated tested by an Instron machine under tension and compression loading. The results have shown that the bending moment resistance of joints under compression was higher than those under tension. The lowest bending moment resistance under tension was seen in particleboard and plywood spline with 14 mm penetration depth while under compression it was seen in particleboard, and HDF spline with 11 mm penetration depth. The highest bending moment resistance under tension was seen in MDF, and plywood spline with 14 mm penetration depth while under compression it was seen in MDF, and HDF spline with 8 mm penetration depth.

In this study, physical and mechanical properties of single layer particleboard made from bamboo powder (with and without alkali treatment) and wood particles were investigated. Bamboo powder (30 mesh particles) was treated with 5% hydroxide sodium for 120 minutes. Industrial wood chips from Sanate Choube Shomal Company were used.The variable in this research were the ratio of bamboo powder (with and without alkali treatment) to wood chips (at four levels; 0:100, 10:90, 20:80, 30:70). Urea formaldehyde resin used at 10 percent level of dry weight of raw material as well as ammonium chloride was used as a catalyst at 2 percent level of the dry weight of adhesive. Physical and mechanical properties of panels measured according to EN Standard. Mechanical properties of the particleboards made from treated bamboo was superior to the relevant untreated bamboo. Water absorption and thickness swelling after 2 and 24 hours immersion in water decreased with alkali treatment. Mercerization, or treating cellulose fibers in alkaline solution, because of fibrillation, the removal of lignin and hemicellulose enhances the mechanical properties and dimension stability of the particleboard by promoting resin-fiber mechanical interlocking at the interface. Results showed, there was usability of the treated bamboo up to 30 percent for general purpose boards for use in dry conditions.

The potential of cotton stalks residues for the production of particleboard was investigated. Three resin dosage gradients (10% core:10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables were produced. Then the mechanical and physical properties of the boards were measured and statistically analyzed. The results of modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) measurements showed that as the resin dosage gradient increases, these properties increased and the effect of this variable on these properties was statistically significant. The highest values were reached when either 2 or 4% resin dosage gradients were applied. The effect of resin dosage gradient on thickness swelling after 2 and 24 hours immersion in water was also statistically significant and these properties were improved. The effect of press time on thickness swelling was also statistically significant and the lowest thickness swelling was observed at 5 minutes press time. The results indicated that if 2 or 4% resin dosage gradients and either 4 or 5 minutes press time is applied for the manufacturing of particleboards using cotton stalks residues, the specification of the boards meet the EN specification.

This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage times (1.5, 3, 4.5 and 6 months) and 2 moisture content of Bagasse (45% and 55%). According to these variables, particleboards were made. Also chemical properties (pH, acid and alkaline buffering capacity) of Bagasse were determined. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. Then Duncan multiple range test was used for grouping of the averages. The results revealed that with decreasing of Bagasse moisture content, Bagasse sample pH and acid buffering capacity were decreased and increased, respectively. Also bending properties and thickness swelling after 24 hours immersion of the boards were improved. With increasing of storage time, the chemical properties of Bagasse tend to be alkaline, and the minimum of board internal bond strength was obtained in 1.5 month storage time. The physical properties of boards were improved with increasing of storage time

The potential of rose flower stalks for the production of particleboard was investigated. Three resin dosage gradients of 0, 2 and 4% (10% core: 10% surface; 9%core:11% surface and 8% core:12% surface) and three press times (3, 4 and 5 minutes) were selected as the variables and boards were produced. Then the mechanical and physical properties of the boards were measured and statistically analyzed. The results of modulus of rupture (MOR), modulus of elasticity (MOE) and internal bonding (IB) measurements showed that as the resin dosage gradient increases, these properties improved and boards produced using either 2 or 4% resin dosage gradients generated the highest values. The effect of resin dosage gradient on these properties was statistically significant. As the resin dosage gradient increases, both thickness swelling after 2 and 24 hours immersion in water was improved. The effect of press time on thickness swelling after 2 and 24 hours immersion in water was also statistically significant and these properties were improved when 5 minutes press time was used The results indicate that if 2 or 4% resin dosage gradients and either 4 or 5 minutes press time is applied for the manufacturing of particleboards using rose flower stalks residues, the specification of the boards will meet the EN specification.

In this study a nontoxic aldehyde with high boiling point entitled glyoxal was used for reaction with urea and Kraft lignin to prepare green adhesive entitled urea- lignin- glyoxal (LUG). The prepared LUG resin had used in particleboard manufacturing. Then the influence of nanoclay addition on various properties of particleboard made from LUG resin was investigated. For this reason, the kraft lignin (10 wt%) was used instead of second urea in urea- glyoxal resin synthesis. After LUG resin synthesis in acidic condition and measuring physicochemical properties of the prepared resins, the prepared LUG resin was mixed with the 0.5, 1 and 1.5% nanoclay by mechanically stirring for 5 min at room temperature. Then the prepared resin was used in particleboard manufacturing. The physical properties of the prepared resins such as viscosity, gelation time, solid content and density as well as physical (water absorption) and mechanical (internal bond strength and flexural properties) properties of manufactured panels were measured according to standard methods. Also X-ray Diffractometry (XRD) was used to investigate the distribution of nanoclay on LUG resin. The physical test results indicated that gelation time of the LUG resin is slower than that of UF resin. Addition of nanocaly from 0.5 to 1.5% accelerates the gelation time of the prepared resins whereas the fastest gelation time related to the LUG resin containing 1.5% nanocaly. Also XRD analysis indicated that nanoclay could good separate when was mixed with LUG resin. Based on obtained result, the addition of nanoclay decreased the water absorption content of the manufactured panels, significantly. The internal bond strength and flexural strength of the panels was increased by addition the amount of nanoclay. Finally it must be noted that the addition of nanoclay had no significant effect on flexural modulus of the manufactured panels.

In this research soy flour- tannin adhesives were used in particleboard preparation, successfully. Tow type of different tannins Mimosa (as condensed tannin) and Chestnut (as hydrolysable tannins) were used for soy resin modification. For this purpose, mimosa and chestnut tannin were added to soy adhesive with 5, 10 and 15 percent based on dry weight of soy flour. 9 percent Glyoxal was used based on dry weight of tannin for accelerate tannin reaction’s with soyflour components. Prepared soy-tannin adhesives were used in particle board manufacturing with 350×300×14 mm3 dimansion and 0.7 g/cm3 nominal density. Results of viscosity measurment showed that addition of each of tannins decreased visocosity of soy adhesive. In this study, result of thermo-mechanical analyze indicated that chestnut cloud improve adhesion behavior of soy adhesive better than mimosa. Also, Using of tannins in soy adhesive composition increase internal bonding and bending properties in manufactured particleboards.

In this study, physical and mechanical properties of particleboard made from recycled newspaper in the surface layers were investigated. Coarse and fine wood chips and recycled newspaper with dimension of 0.5 × 4 cm2 were used. The variable in this research were the ratio of recycled newspaper to wood chips (at five levels; 0:100, 15:85, 30:70, 45:55, 60:40). Urea formaldehyde resin used at 10% content on dry weight basis of the wood particles and newspaper and ammonium chloride was used as a catalyst to 2% of the dry weight of adhesive. Physical and mechanical properties of panels measured according to EN Standard. The results showed that panels containing recycled newspapers at the level of 45% had the highest bending strength and modulus of elasticity. Internal bonding and screw holding strength decreased with increasing of recycled newspaper and control sample had the highest strength. Water absorption and thickness swelling increased with increasing of recycled newspaper portion. On the basis of results of this study can be concluded that particleboard containing recycled newspapers in the surface layers up to the level of 30% can be used for general purpose boards and interior fitments (including furniture) for use in dry conditions.

The aim of this study has been utilization of recycled polyethylene in modification of physical and mechanical properties of particleboard. Therefore, three levels of resin consumption content ( 10, 7 and 4% ) and three levels of recycled polyethylene consumption content 5, 10 and 15% in surface layer of mat, particleboards produced. Also in order to influence of these variables on physical and mechanical properties of produced boards, 3 particleboards with 10% resin content in surface layer and without polyethylene as control samples produced. The physical and mechanical properties of boards measured and analyzed. The results of this study indicated that with increasing of the recycled polyethylene consumption content, the MOR, MOE and thickness swelling of boards improved significantly and the produced boards with 15% recycled polyethylene in compare with control boards increased 59 and 53% respectively. Also the results revealed that the water absorption of boards decreased with increasing of increasing of recycled polyethylene consumption content, and the minimum of water absorption of boards observed in the produced boards with 15% recycled polyethylene. Based on the results of this research and with increasing of polymeric residues in the envirement , we conclude that the utilization of recycled polyethylene in particleboard production has different advantages.

In this study, the creep behaviors of composite panels used in library shelves were investigated. For this purpose, two types of wood-composite panels (medium density fiberboard and particleboard), and three types of covering including synthetic laminates, natural veneer, and without cove, and two types of wood joints (fixed and detachable) were used. Dimensions of the book-shelves were in actual shelf size, that is, 1,000 × 300 mm. Totally, 48 shelf specimens were prepared. For the creep test, a 23.5 kg loading level was applied in the center part of the shelves. Measurements on the creep behavior were carried out over 155 days at different intervals. Results indicated that the type of wood-composite as well as the type of veneer had statistically significant effect on the creep behaviors of panels. The lowest creep was observed in MDF panels. Moreover, those panels covered with natural veneer demonstrated significantly lower creep values. The type of joint also had a significant effect on the creeping behavior of the shelves, though not as conspicuous as the type of panels and veneers. Based on the results of the present research project, it is suggested that in order to increase the service life of library shelves it would be better to produce the shelves from MDF panels covered with natural veneers; these shelves should be fixed on supports.