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.
Hossein Familian; Davood Parsa pazhoh; Abdilrahman Hosseinzadeh; Ahmad Jahan latibari
Abstract
In this investigation, Biological, Anatomical, Physical and Chemical Characteristics of the Phragmites australis Var australis (Cav) Trin. Where investigated in nine plots, at the Hooralazim in southern Iran and talab Anzali in northern of Iran. investigation of biological characteristics indicated ...
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In this investigation, Biological, Anatomical, Physical and Chemical Characteristics of the Phragmites australis Var australis (Cav) Trin. Where investigated in nine plots, at the Hooralazim in southern Iran and talab Anzali in northern of Iran. investigation of biological characteristics indicated that the mean culm diameter the culm pith diameter and internod length of reeds in the north is more than south. The average biological characteristics of P. australis is: culm length, 5.17 mm.; culm diameter, 13.99 mm. culm pith diameter 10.98 mm.; culm wall-thickness, 1.33mm.; Number of nods, 31 and internod length, 10.22 cm. Investigation of Physical characteristics indicated that, density, shrinkage and swelling, in samplaes from south is significantly higher than samples from north. The investigation of chemical characteristics indicated that, there is not significant difference between chemical characteristics.
Ahmad Jahan latibari; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Abolfazl Kargarfard; Habib alah Arabtabar
Abstract
pH and buffering capacity of nine Iranian commercial hardwoods from Caspian sea forests are determined. Selected woods includes Elm, Maple, Hornbeam, (White beech), basswood (lime tree), Alder, Beech, Persimmon (diospyros lutos), Oak and Ironwood. This study was conducted using procedure developed Johns ...
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pH and buffering capacity of nine Iranian commercial hardwoods from Caspian sea forests are determined. Selected woods includes Elm, Maple, Hornbeam, (White beech), basswood (lime tree), Alder, Beech, Persimmon (diospyros lutos), Oak and Ironwood. This study was conducted using procedure developed Johns and Niazi. pH of these woods ranged from 4.44 for Oak to as high as 5.37 for basswood. pH of bark extract was always lower than debarked wood with the exception of Maple, Persimmon and Oak. Furthermore heartwood of all these species is more acidic than sapwood with the exception of Oak. Acid buffering capacity of these woods ranged between 0.0046 to 0.1481 mili-equivalent normal NaOH for one gram of wood and base buffering capacity varied between 0.0310 to 0.0768 mili-equivalent normal H2So4 for one gram of wood. Buffering capacity of bark is also measured and it was found that acid or base buffering capacity of wood and it anatomical components is additives.
