Composite wood products
Mohsen Saffari; mohammad reza ranjbar; mohammad ali ghavidel; abdollah hosseinzadeh
Abstract
AbstractThe aim of present study was to determine the relationship between ultrasonic wave velocity and mechanical properties of particleboard panels. For this purpose, homogenous and layering particleboards were made by 0/7 g/cm3 density and 16 mm thickness. After conditioning and preparing samples, ...
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AbstractThe aim of present study was to determine the relationship between ultrasonic wave velocity and mechanical properties of particleboard panels. For this purpose, homogenous and layering particleboards were made by 0/7 g/cm3 density and 16 mm thickness. After conditioning and preparing samples, ultrasonic wave velocity was measured in different directions of samples. Then modulus of elasticity, modulus of rupture and internal bonding of samples were measured by mechanical test machine. Result indicated that ultrasonic wave velocity of particleboard samples was higher in longitudinal direction than other directions. Relationship between ultrasonic wave velocity and mechanical properties was determined by linear correlation regression. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples. Correlations between ultrasonic wave velocity and modulus of elasticity, modulus of rupture and internal bonding were significant in thickness direction of particleboard samples.
Composite wood products
masoudreza habibi; Saeed Mahdavi; Hossein Hosseinkhani
Abstract
In this study, MDF was produced from Reed ( Phragmites australis ). Reeds are collected from Talabe - Anzalye areas. The treatments conditions for fiber preparing were as follows:-Steaming temperature 170°c, 180°c-Steaming time 5, 10, 15 minutesThe other production variables were constant. The ...
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In this study, MDF was produced from Reed ( Phragmites australis ). Reeds are collected from Talabe - Anzalye areas. The treatments conditions for fiber preparing were as follows:-Steaming temperature 170°c, 180°c-Steaming time 5, 10, 15 minutesThe other production variables were constant. The anatomical properties of Reed such as fiber length, fiber diameter, lumen cell diameter, and cell wall thickness were measured respectively 1.38mm, 17.07, 6.15, 5.46 micron. LID ratio of Reed fiber was measured 80.84. The physical and mechanical properties of MDF were determined according to DIN standard. The measurements of bending properties and IB of MDF revealed that increasing steaming time and steaming temperature caused to decrease MOR, MOE and IB.Also the results of MDF dimentional stabilities indicated that Thickness Swelling after 2 and 24 hours decreased upon increasing steaming time and steaming temperature. Degradation of hemicellulose chains may be the reason of decreasing Thickness Swelling.
Composite wood products
masoudreza habibi; Saeed Mahdavi; Hossein Hosseinkhani; Sayed javad Sepideh dam
Abstract
In this study, MDF was produced from Reed (Phragmites australis). Reeds are collected from Hor-Alazym area. The treatments conditions for fiber preparing were as following:- Steaming temperature 170, 180oC(Steaming pressure 7,9 bar).- Steaming time 5, 10, 15 minutes.The other production variables were ...
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In this study, MDF was produced from Reed (Phragmites australis). Reeds are collected from Hor-Alazym area. The treatments conditions for fiber preparing were as following:- Steaming temperature 170, 180oC(Steaming pressure 7,9 bar).- Steaming time 5, 10, 15 minutes.The other production variables were constant.The anatomical properties of Reed such as Fiber length, fiber diameter, lumen cell diameter, and cell wall thickness were measured. LID ratio of Reed fiber was measured 73.69. The physical and mechanical properties of MDF were determined according to DIN standard. The measurements of bending properties and IB of MDF revealed that increasing steaming time and steaming temperature caused to decrease MOR, MOE, and IB.Also the results of MDF dimentional stabilities indicated that Thickness Swelling after 2 and 24 hours decreased upon increasing steaming time and steaming temperature. Degradation of hemicellulose chains may be the reason of decreasing Thickness Swelling.
Composite wood products
masoudreza habibi; Abdolrahman Hosseinzadeh; Hossein Hosseinkhani; Saeed Mahdavi
Abstract
In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. ...
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In this study the effect of two variables, (resin content and press time) on properties of MDF was investigated. Levels of each variable was as follow: Resin content (8, 9.5, 11 percent) Press time (4, 5, 6 minutes). The statistical analysis proved that the effect of press time on MOE and MOR was significant. MOE and MOR were the highest at press time of 6 minutes. According to Duncan's test, there aren’t any significant differences between MOE at press time of 5 and 6 minutes. Also the effect of resin content on MOE had significant differences. MOE was the highest at resin content of 11%. There aren’t any significant differences between MOE on resin content at 9.5% and 11% levels. The results showed that effects of press time and resin content had significant differences on IB. IB was the highest at press time of 6 minutes and resin content of 11%. There aren’t any significant differences between IB on resin content at 9.5% and 11%. The effects of press time and resin content had significant differences on thickness swelling after 2 hours. Thickness swelling was the lowest at press time of 6 minutes and resin content of 11%. According to the results of this study optimum combination for MDF production from baggasse includes resin content and press time of 9.5% and 5 minutes respectively.
Composite wood products
Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Taghi Tabarsa
Abstract
In this investigation, the effect of mat moisture content, press temperature and time on polymerization reaction of urea-formaldehyde (UF) resin and the strength of UF bonded hornbeam particleboard is studied. Variation of three variables is as followed:
-mat moisture content; 10, 13 and 16% (Based ...
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In this investigation, the effect of mat moisture content, press temperature and time on polymerization reaction of urea-formaldehyde (UF) resin and the strength of UF bonded hornbeam particleboard is studied. Variation of three variables is as followed:
-mat moisture content; 10, 13 and 16% (Based on oven dry weight of wood)
-Press temperature; 150, 170 and 190 ᵒC
-Press time; 4, 6, and 8 min.
Fore boards were manufactured for each combination of variables. Modulus of rupture (MOR), modulus of elasticity (MOE), Internal bond (IB), water absorption (Wa2 and Wa24) and thickness swelling (Ts2 and Ts24) after 2 and 24 hours immersion in water were determined according to ASTM 1037 standard. All data was analyzed using factorial design. The effect of mat moisture content on MOR was not statically different, but its effect on MOE was statistically different at 5% significance level, and increasing the mat moisture content from 10 to 16% bout MOR & MOE. Highest level of MOE (4262 MPa) corresponds to board pressed at 16% mat moisture content. On the contrary, mat moisture content decreased the IB and lowest value of IB ( 1.447 MPa) corresponds to boards pressed at 16% mat moisture content. The effect of mat moisture content on IB was statistically different at 1% significance level. Increasing mat moisture content decreased water absorption and increased thickness swelling. Lowest Wa2 & Wa24 was observed on boards pressed at 16% mat moisture content (67.35% & 86.78% respectively) and lowest Ts2 & Ts24 was observed on boards pressed at 10% mat moisture content (21.89% & 27.32% respectively). There force for the production of suitable boards, ma moisture content must be kept at 10-13% range.
