In this study, effects of PRESS TEMPERATURE and PRESS time on the physical and mechanical properties on the OSB has made from Aspen were investigated. Two levels of PRESS TEMPERATURE 175oC and 1850C and two levels of PRESS time 5 min and 6 min were applied as variables for manufacturing boards. Mechanical and physical properties such as bending strength, internal bond, water absorption and thickness swelling were measured. Results showed that, increase in PRESS TEMPERATURE and PRESS time causes significant increase on bending strength, internal bond, water absorption and thickness swelling. The best boards were made of PRESS TEMPERATURE of 185ºC and PRESS time 5 minutes.

In this investigation, the influence of PRESS TEMPERATURE and PRESS time on MDF properties made from Eucalyptus wood (Eucalyptus intertexta sp.) have been studied. Variable factors were steaming time (in two levels: 5 and 10 minutes), PRESS temprature (in two levels: 180 and 190oC ) and PRESS time (in three levels: 3, 3.5 and 4 minutes). The results of this study indicated that the effect of steaming time on MOR had been significanted, the highest MOR were obtained 14.62 Mpa in MDF boards that produced in 5 minutes steaming time. Also the MOR of boards were increased with ascending of PRESS TEMPERATURE. The results also showed that the effect of PRESS TEMPERATURE on MOE had been significanted and MOE of boards were increased with ascending of PRESS TEMPERATURE. The results revealed that increasing of steaming time and PRESS time had negative effect on IB. on the other hand PRESS time  had a significant effect on  thickness swelling as the minimom of thickness swelling had obtained in 3 minutes PRESS time.

In order to investigate the effects influence of PRESS time and TEMPERATURE on development of particleboard strength and reach the minimum energy consumption and PRESS time, two PRESS TEMPERATUREs of 165G and 185G and three PRESS times of 3, 4 and 5 minutes were selected. Heat transfer from the mat surface to core was determined by placing thermocouple at different locations in board thickness. Mechanical properties of boards were determined and the relation between board properties and heat transfer measurement especially time to reach the TEMPERATURE of 100G at the core was analyzed. The results indicate that PRESS time and TEMPERATURE did not significantly but the influence of these variables on MOE was significant, and increasing PRESS TEMPERATURE reduced MOE. The influence of both variables on IB was significant, increasing these variables increased IB. The results of heat transfer measurement indicate that increasing PRESS TEMPERATURE reduced the time to reach 100G at the core, which caused an increase in IB. This indicates that at higher TEMPERATURE and PRESS time sufficient time is available for resin to develop bond strength.

The objective of this investigation was the utilization of corn stalk in Medium Density Fiberboard (MDF) production. Therefore 27 laboratory MDF boards were produced using three PRESS TEMPERATUREs of 165, 175 and 185oC and three PRESS duration of 3, 3.5 and 4 minutes. The mechanical and physical properties of the boards were measured and the results were statistically analyzed. The results indicated that PRESS TEMPERATUREs and PRESS duration did not impose significant effect on MOR, but with increasing the PRESS TEMPERATURE and PRESS duration, the MOE of the boards improved and the highest MOE was observed applying 185oC PRESS TEMPERATUREs and 4 minutes PRESS duration. The internal bonding (IB) of boards increased with increasing PRESS duration, and the highest IB was related to boards produced with 3.5 and 4 minutes PRESS duration. The PRESS duration significantly influenced the thickness swelling after 2 and 24 hours immersion in water, and the lowest values were observed in boards produced applying 3.5 minutes PRESS duration, as expected from the results of highest IB at same condition. Generally it can be exPRESSed that corn stalk shows the potential as raw material to produce standard Medium Density Fiberboard.

The utilization of beech waste veneers collected from a veneer mill for manufacturing oriented strand board (OSB) was studied. Core strand orientation (parallel to the surface layer, right angle to the surface layer and randomly oriented), PRESS TEMPERATURE (170°C and 190°C) and PRESS time (10 min. and 15 min.) were considered as variables. Strand dimension, board thickness, board density, resin type, resin amount, PRESS PRESSure and PRESS closing time were kept constant for all manufactured board. Physical and mechanical properties of boards were determined. Results showed that when strands laid parallel to the surface layer, Modulus of rupture (MOR) and Modulus of elasticity (MOB) reach the highest values however the highest internal bond and lowest thickness swelling were observed in boards in which core strands were laid cross to the surface layer. PRESS TEMPERATURE and PRESS time had modifying effects on board properties. It was concluded that beech waste veneers' can be recycled and used as raw material for producing OSB.  

The objective of the present study was the utilization of cotton stalk residues for medium density fiberboard production. MDF was produced applying three PRESS TEMPERATUREs (170, 180, and 190 oC ) and three PRESSing times (3, 4 and 5 minutes). The properties of the laboratory boards were measured and the results are analyzed applying factorial experiment and randomized design. In case, the statistical difference was observed between the averages, then Duncan Multiple Range Test was used for grouping the averages. The results showed that as either PRESS TEMPERATURE or PRESS time is increased, the modulus of rupture of the boards was significantly improved and the highest value was reached when 190 oC PRESS TEMPERATURE and 5 minutes PRESS time was applied. The internal bonding of the boards was significantly higher when 180 oC PRESS TEMPERATURE was applied. The effect of PRESS TEMPERATURE on thickness swelling after 2 and 24 hours immersion in water was statistically significant and the lowest values were obtained when 190 oC PRESS TEMPERATURE was used. The results of this study indicated that the cotton stalks can be considered as a potential raw material for medium density fiberboard production and the properties of the boards meets the EN requirements.

In this investigation, the effect of paraffin content and PRESS time and TEMPERATURE on practical properties especially surface roughness of particleboard is studied. The variables such as paraffin content at 0, 1& 2 percent, PRESS TEMPERATURE at 170o and 180° C and PRESS time of 4 and 5 minutes were investigated. Modulus of rupture, modulus of elasticity, shear strength, water absorption and thickness swelling after 2& 24 hours soaking in water & surface roughness were measured.The results indicate that there is no significant difference on the influence of paraffin content on either MOR & MOE of the particleboard. But increasing paraffin content decreased shear strength of panels. However, addition of paraffin reduced water absorption and thickness swelling.PRESS TEMPERATURE had no significant influence on measured properties, but this variables increased surface roughness. Increasing PRESS time, improved MOE, but showed no significant influence on other properties.

In this research, the effect of PRESSing conditions on the green and environmentally friendly particleboard made from natural adhesive of mimosa condensed tannin was studied. PRESSing TEMPERATURE was fixed at 200 °C. PRESS time in four levels of 3, 4, 5, and 7 minutes and PRESS PRESSure in three levels of 15, 18 and 22 kg/cm2 were considered as the variable factors. The results showed that the best treatment in the terms of internal bond strength and thickness swelling are PRESSing conditions with TEMPERATURE of 200 °C, PRESSure of 18 kg/cm2, and time of 5 minutes. In such conditions, the internal bond of 0.59 MPa was obtained, and the percentage of thickness swelling (2 and 24 hours) decreased compared to the other treatments. It was found that water absorption continued to decrease with increasing PRESS PRESSure up to the level of 22 kg/cm2.

One of the important issues in the production of concrete is environmental variability that affects the concrete and elements constructed from this material. Due to the importance of different characteristics of concrete in short- and long-term conditions, this article aims to investigate the influence of initial TEMPERATURE conditions of self-compacting concrete on its long-term characteristics and determine the initial optimal TEMPERATURE of concrete. For these purposes, several experiments under three TEMPERATURE conditions of 5, 20, and 40 degree-of-Celsius were conducted to evaluate the rheology and mechanical properties of fresh concrete in the range of 7 and 28 days. In these experiments, alternative mineral admixtures of cement such as micro-silica, fly ash, and zeolite were used to build the concrete specimens. Results demonstrate that the mechanical properties of the specimens increase with increasing initial TEMPERATURE in the short term, while such properties significantly decrease in the long term compared to the specimens constructed under lower initial TEMPERATURE. Moreover, the fluidity of self-compacting concrete increases with increasing initial TEMPERATURE.

In this study, the possibility of three-layered oriented strand board production from hornbeam (Carpinus betulus L. ) wood was investigated. Two PRESS times (6 and 8 minutes) and three PRESS TEMPERATUREs (180˚ C, 200˚ C and 220˚ C) were applied and 12 mm thick laboratory boards were made from hornbeam wood strands. The strands on the surface layers were aligned in the longitudinal direction of the board and the middle layer strands are cross aligned to the surface layers. In all treatments, board density of 0/7 g/cm 3 and mat moisture content of 7% and phenol-formaldehyde resin (PF) content of 7% based on the oven dry weight of the strands were kept constant. The mechanical and physical properties of the boards were measured as defined in relevant European standards test methods EN 300. The internal bond (IB) and thickness swelling (TS24) of boards were significantly improved as the PRESS time increased from 6 to 8 minutes. The modulus of rupture (MOR) and internal bound (IB) and thickness swelling (TS24) were significantly improved as the PRESS TEMPERATURE increased from 180˚ C to 220˚ C. Overall results showed that the highest MOR and IB and the lowest TS24 were reached at 8 minutes PRESS time and 220˚ C PRESS TEMPERATURE and the properties of all boards made applying these conditions exceed the EN 300 standards values for MOR, MOE, IB and TS24.