The effect of press temperature and press time on Medium Density Fiberboard (MDF) properties produced from EucalyptusIntertexta fibers

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 190 °C ) 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 significant, 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 significant and MOE of boards were increased with ascending of press temperature. The results revealed that increasing of steaming time and press time had been 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

The impact of reeds residue addition on physical and mechanical properties of particleboard made from pomegranate prunings

The impact of reeds residue addition on physical and mechanical properties of particleboard made from pomegranate pruning was investigated. Laboratory particleboard  was made applying one of the three levels of   press time (3, 4 and 5 minutes) and  one of the four levels of reed and pomegranate pruning mixture (1-100% reeds; 2- 75% reeds + 25% pomegranate pruning; 3- 50% reeds + 50% pomegranate pruning and 4- 25% reeds + 75% pomegranate pruning). Boards were made in three replicate and 36 boards were made. Boards were tested using relevant EN standard and results were analyzed based on complete randomized design (CRD) under factorial experiment. Results revealed that increasing of pomegranate pruning in the wood mixture imposed positive effect on MOR, MOE, IB and thickness swelling of the particleboard. The relevant values of MOR, and MOE of the boards produced using 25% reeds + 75% pomegranate pruning  were determined as 16.20 MPa and 2533 MPa respectively. Also thickness swelling after for 2 and 24 hours soaking in water decreased from 17.51 and 33.21% to 9.33 and 16.84% respectively. Internal bond strength (IB) of boards made applying 3 minutes press time (0.17 MPa.) was higher than boards made pressed for either 4 or 5 minutes, which indicates that 3 minutes press time is the appropriate time to approach maximum MOR and minimum thickness swelling after 24 hours soaking in water

Investigation on the Properties of Cement Fiber Board Produced Using Waste Paper

In this study, the reinforcing effect of recycled newsprint paper (RNP) in cement boards has been investigated. The experiment was designed to apply two variable factors, RNP and calcium chloride (CaCl2). Cement-fiber boards with the density of 0.7 kg/m3 were manufactured using fiber/cement ratios of 10:90, 15:85, 20:80 and 25:75 (w/w) and 3% and 5% CaCl2 as accelerator. Minimum four boards (replications) were fabricated for each combination of variables, and the mechanical and physical properties of the boards were evaluated. The statistical analysis showed that the effect of the RNP and CaCl2 contents on modulus of rupture of cement fiber boards were significant at 1% significant level. The results showed that addition of CaCl2 enhanced the mechanical properties of the boards. All properties of the boards were improved as the CaCl2 content was increased from 3% to 5%. The modulus of rupture and modulus of elasticity of the boards decreased with addition of RNP, and the maximum values were obtained at RNP loading of 10%. The results also showed that as the fiber content was increased, significant increase in water absorption and thickness swelling occurred. Increasing RNP fiber content from 10% to 25% reduced both the mechanical and physical properties considerably. The optimum condition was obtained when the RNP and CaCl2 contents were 10% and 5%, respectively

INVESTIGATION ON THE POTENTIAL OF EUCALYPTUS CAMALDULENSIS WOOD IN PARTICLEBOARD INDUSTRY

In this investigation Eucalyptus camaldulensis wood for particle -board production and determinating physical and mechanical properties of boards have been studied. Variable factors such as resin content in three levels (9, 10 and 11 percent) and press time in three levels (5, 6 and 7 minutes) were investigated.Other factors such as resin type, hardner type, closing press time, mat moisture, board density and etc. were assumed constant. Three boards were produced for each combination of variables. Based on the DIN-68763 standard physical and mechanical properties including Modulus of Rupture (MGR), Modulus of Elastisity (MOE), Internal Bonding (IB) and thickness swelling (TS2 and TS24) after 2 and 24 hours immersion in water were tested.Based on the factorial experimental design at completely random block test data was analysis. The rcsuHs showed that polymerization of resin could be better at the amount of 11 percent resin content and 7 minutes of press time for partideboard production from Eucalyptus camaldulensis wood

Investigation of OCC Fiber/Polymers Composites in Air – Forming Production

This study investigated the effects of production variables on physical and strength properties of air-formed OCC fibers / polymer composites. A combination of 12  treatments of OCC fibers and coupling agents for air-forming were investigated. Physical and mechanical properties of the sample were analyzed using factorial experimental design with completely randomized and DMRT test is used to classified the averages. The results of this study showed that addition of 70% OCC fibers to the polymers in air forming resulted in composites with higher strengths and modulus of rupture and 55% OCC fibers increased internal bonding, tensile strength and modulus, and lowered thickness swelling. Thickness swelling after 2 h water-soak and mechanical properties were improved by addition 2 and 4 % coupling agen

THE EFFECT OF HEAT ON WOOD ACIDITY IN PARTICLEBOARD PROCESS

In order to investigate the influence of processing variables such as particle drying temperature, press temperature and hardner consumption on wood acidity and bonding performance of UF resin, experimental boards were produced using beech wood particle, drying temperature varied at 80, 110 and 140°C, press temperature at 150, 165 and 180°C and hardner consumption at 1, 1.5 and 2% (based on solid content of UP resin). Eighty one sample boards were produced and tested. The results of physical and mechanical properties measurements were as follows: Modulus of rupture and modulus of elasticity of boards produced with particles dried at 80°C were higher than 110 and 140°C. Application of 2% hardener with increasing press temperature decreased MOR and MOE. Internal bonding of boards were measured and the results indicated that drying temperature had significantly effected the IB and boards produced  with particles dried at 80 and 140°C, produced highest IE and lowest IE was belong to 110°C. The effect of hardner consumption was statistically significant and the highest IB was belonging to 2% hardner consumption. The results of thickness swelling measurement after 2 hr. soaking in water indicated that T.S2 of boards produced with particles dried at 140°C were the lowest. The combined effect of press temperature and hardner consumption on T.S2 was statistically significant and at 2% hardner consumption with increasing press temperature, increased thickness swelling

The mechanical properties of Pinus taeda L. wood growing in different regions of Caspian forests

The major engineering properties of Pinus taeda L. wood growing in different regions of Caspian forests (North of Iran) was determined. Test materials were selected randomly from Pinus teada tree plantation and the test specimens were prepared according to ASTM D-143 standard. Mechanical and physical properties were measured on both green and air-dried samples (12% moisture content). The results of the measurement were statistically analyzed based on randomized block design and factorial experiment. The influence of specimen locations at different stem heights was examined. Based on the results of this study, statistically significant difference of the measured properties was not observed between the samples collected from different regions. Toughness was not influenced by moisture content, but the compression strength perpendicular to the grain of wet and air-dry specimens was not similar. Mechanical properties of Pinus teada wood grown in Iran is generally of lower quality compare to those in their original habitat