Research Paper
Noraldin Nazarnezhad
Abstract
This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, ...
Read More
This research was conducted to investigate the posibility of producing particleboards using surface activation method of P. deltoides particles and then using cross-linking agents to bond wood particles. At first, nitric acid as an oxidative agent at different proportion including 0, 3, 4.5 & 6 percent (based on OD weight of wood) and two assembly times of 0 and 1 hour was used. Black liquor at two amounts of 5 and 7 percent was used as cross-linking agent. The results indicates that using 6% nitric acid and 7% liquor had the best performance and that, the assembly time of 1 hour had negative effect on all properties. The ATR spectrum of treated samples showed the increase in the absorbtion rate at 1740 cm-1 related to COOH group as compared with control samples. In addition, the spectrum indicated that increasing oxidation increase absorbtion rate of COOH group.
Research Paper
Chemistry of wood
Ahmad Mirshokraei
Abstract
In this study, changes in optical behavior of poplar Kraft lignin and bagasse Soda lignin, before and after reducing with sodium borohydride and sodium hydrosulfite (dithionite) and also after methylation using dimethyl sulfate, was monitored by measuring optical indices (brightness, k/s, whiteness and ...
Read More
In this study, changes in optical behavior of poplar Kraft lignin and bagasse Soda lignin, before and after reducing with sodium borohydride and sodium hydrosulfite (dithionite) and also after methylation using dimethyl sulfate, was monitored by measuring optical indices (brightness, k/s, whiteness and Post-Color numbers) of impregnated papers following accelerated thermal aging. The structural changes in lignins caused by reductive reactions, were mostly verified by using absorbance changes (UV-Vis spectrometry) and FI-IR spectroscopy. It was observed that, regarding elimination of chromophoric carbonyl and quinone groups, sodium borohydride showed better and more sustainable performance than sodium hydrosulfite. Therefore, it could be inferred that to improve the brightness of lignin-containing papers and persistance of this brightness, sodium borohydride could exhibit more efficiency and higher applicability.
Research Paper
Abolfazl Kargarfard; Amir Nourbakhsh; Fardad Golbabaei
Abstract
In this investigation, 36 laboratory medium density fiberboard (MDF) panels were produced using Alder wood fibers. Variables factors were steaming time ( 5, 10 and 15 minutes), press time (4 and 6 minutes) and resin consumption (9 and 11%). The physical and mechanical properties of panels were measured ...
Read More
In this investigation, 36 laboratory medium density fiberboard (MDF) panels were produced using Alder wood fibers. Variables factors were steaming time ( 5, 10 and 15 minutes), press time (4 and 6 minutes) and resin consumption (9 and 11%). The physical and mechanical properties of panels were measured and analyzed. The results indicated that the maximum MOR was observed panels produced applying 6 minutes press time and resin consumption of 11%. The maximum Internal Bonding (IB) was related to panels made employing steaming time of 15 minutes and resin consumption of 11%. However, test panels produced at 6 minutes press time showed minimum of thickness swelling. The results indicated that the MDF boards produced from alder wood fibers exhibit desirable physical & mechanical properties were above than EN standard requirement. Consequently application of alder wood fibers to improve physical & mechanical properties of MDF panels which are produced from nonwood materials and agricaltural residues is recommended.
Research Paper
Khodadad Malmir cheghini; Mohammad Talaeipoor; Shademan Pormosa
Abstract
Paper and ink characteristics effect on print density were investigated. For this purpose three types of papers and four types of printing inks at 2 viscosities levels (25-30, 50-55) were used. Then characteristics of paper & ink were measured. Inks on sampled papers Printed and then printing ...
Read More
Paper and ink characteristics effect on print density were investigated. For this purpose three types of papers and four types of printing inks at 2 viscosities levels (25-30, 50-55) were used. Then characteristics of paper & ink were measured. Inks on sampled papers Printed and then printing density was measured. Statistical analysis was conducted based on a complete randomized design in factorial experimental model and means were analyzed and grouped by Duncan multiple range test (DMRT) using SPSS software. Result indicated that Solid content, pH and particles diameter of inks have significant effect on print density. While roughness and water absorption of papers do not have on significantly influences print density. There was not any significant different between two viscosity level and print density
Research Paper
Composite wood products
masoudreza habibi; Hossein Hosseinkhani; Saeed Mahdavi; Sayed javad Sepidehdam
Abstract
In this study, particleboard was produced by Eucalyptus and Poplar wood mixture. Variations of this study were as follow: - Combinations of Eucalyptus and Poplar wood were (%100 , %0) , (%66.5 ,% 33.5) , (%33.5 ,% 66.5) and (%0 ,% 100) respectively. ...
Read More
In this study, particleboard was produced by Eucalyptus and Poplar wood mixture. Variations of this study were as follow: - Combinations of Eucalyptus and Poplar wood were (%100 , %0) , (%66.5 ,% 33.5) , (%33.5 ,% 66.5) and (%0 ,% 100) respectively. - Resin content ( %8 and %10) Physical and mechanical properties of boards such as MOR, MOE, IB TS2 and TS24 were tested according to EN standard. The effects of raw materials combinations on bending properties were significant. Maximum of MOE and MOR were observed in %66.5 of Poplar wood and % 33.5 of Eucalyptus wood. As expected, Physical and mechanical properties of boards were improved by increasing of resin content. Results indicated that TS2 and TS24 were increased with increasing of Poplar wood in combinations. Also the minimum of these properties were obtained in combinations of Eucalyptus and Poplar wood, %100, %0 respectively.
Research Paper
MOHAMMAD MAHDI BARAZANDEH; Abbas Fakhryan roghani
Abstract
Bagasse pulping process was conducted using soda liquor in five maximum cooking temperatures, 80, 100, 120, 140 and 160 degree centigrade. To evaluate rate equations of delignification reaction in each temperature, pulping was done in the same alkali and liquor to bagasse ratio but varying cooking ...
Read More
Bagasse pulping process was conducted using soda liquor in five maximum cooking temperatures, 80, 100, 120, 140 and 160 degree centigrade. To evaluate rate equations of delignification reaction in each temperature, pulping was done in the same alkali and liquor to bagasse ratio but varying cooking times and the results were presented in the form of rate equations with respect to residual lignin concentration in the pulp. The rate equations revealed that delignification reaction rate of bagasse depends both on cooking temperature and residual lignin concentration. The order of rate equation in higher temperatures is far higher than those in low temperatures and due to this, reaction rate in high temperatures is more dependent on residual lignin concentration and far than the rate reaction in lower temperatures. With reaction progressing, the difference between the two rate reactions is reduced and after one point it will be reversed. Using experimental data, the order of delignification reaction rate in temperatures 80, 100, 120, 140 and 160ْC were obtained as 4.6, 4.6, 5.5, 22.8 and 22.7 respectively. The rate constants were also calculated as 1.3×10-5 conc.-3.6 min.-1, 1.1×10-4 conc.-3.6 min.-1, 7.2×10-5 conc.-4.5 min.-1, 6.2×10-10 conc.-21.8 min.-1, 4.0×10-11 conc.-21.7 min.-1, respectively.
Research Paper
Pulp and paper
Abas Fakhryan; Fardad Golbabaei; Mohammad mehdi Brazandeh
Abstract
In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness ...
Read More
In this research pulp and paper making characteristics of Sequoia sempervirens from Chamestan noor research station were studied. The dry and critical specific gravity of sap wood 0.352 and 0.324, heart wood 0.43 and 0.40, fiber length 2.01 mm. diameter 39.84µm. lumen 33.15µm and cell thickness wall 2.89µm were measured as respectively. The amount of cellulose of 52.63%, lignin 35.32%, ext. 6.68% and ash 0.45% were obtained as well. Kraft process was used for pulping. The yield of these pulps in 12% effective alkali were measured as 56% and in 18% effective alkali 39.69% respectively. In 3 hours of cooking time, the tear strength of these pulps 19.74 mNm2/gr and In 2 hours of cooking time 15.22 mNm2/gr respectively were measured.
Research Paper
Hossein Shob chary; Ahmad reza Saraeyan; Ali Ghasemian
Abstract
This study was conducted to investigate the properties of cotton stalks APMP pulp. APMP prepared from chipped cotton stalks. the pulps were prepared separately from debarked and bark containing stalks using three two-stage treatments.Sodium hydroxide charge as a constant level of 4% and hydrogen ...
Read More
This study was conducted to investigate the properties of cotton stalks APMP pulp. APMP prepared from chipped cotton stalks. the pulps were prepared separately from debarked and bark containing stalks using three two-stage treatments.Sodium hydroxide charge as a constant level of 4% and hydrogen peroxide at three levels of 0, 1 and 2% were used in to two-stages, sodium hydroxide as a constant level of 2% and hydrogen peroxide at three levels of 2, 3, 4% were applied. Other conditions of pulping was time's of 20 min for first stage and 100 min for second stage, temperature 70°C and l/w:6:1 as fixed factors considered. Pulp yield determined after neutralization and defiberation. All the pulps were refined up to 300 (ml, CSF) freeness and handsheets were made, then and properties of papers measured using TAPPI standards. Results showed that the pulp yield and brightness was higher in free-bark compared to bark-containing conditions. Also paper produced in free-bark condition with cotton stalks core, resulted the higher tensile and burst indexes and higher breaking length compared to whole cotton stalk.While tear index didn’t show significant difference.Generally, caliper and bulk rates were high in total treatments (free-bark and bark-containing conditions) from cotton stalk APMP process.
Research Paper
Meisam Aliabadi; Eiman Akbaepoor; Ahmad reza Saraeian
Abstract
In this study, the effect of organic complex "sulvy-x" on the optical properties of hornbeam CMP pulp bleached with hydrogen peroxide was investigated. Sulvy-x was used in two sequences silicate-free and silicate containing in hydrogen peroxide bleaching. The brightness of papers increased to 60.52 and ...
Read More
In this study, the effect of organic complex "sulvy-x" on the optical properties of hornbeam CMP pulp bleached with hydrogen peroxide was investigated. Sulvy-x was used in two sequences silicate-free and silicate containing in hydrogen peroxide bleaching. The brightness of papers increased to 60.52 and the yellowness decreased to 22.6 with increasing silicate charges up to 1% . However, at higher levels than 1% , the brightness decreased and the yellowness increased. Without dosage of sodium silicate but using 0.5% of sulvy-x, maximum brightness of 59.3% and minimum yellowness of 23.4 % ISO was achieved. In silicate-containing bleaching, combination of 0.5% sulvy-x and 0.7% sodium silicate resulted the highest brightness (60.28 % ISO) and the lowest yellowness (23 % ISO). Optimum charge of sodium hydroxide and hydrogen peroxide were determined as 2.5% and 5%.The best time for bleaching of hornbeam CMP pulp was 90 minutes in either sequences. With regard to results obtained, utilization of the organic complex of sulvy-x could be a suitable substitution for sodium silicate which produces the pulp with higher brightness and lower yellowness in conventional peroxide bleaching.
Research Paper
Alireza Mohammadi; Taghi Tabarsa; Mohammad Tasooji
Abstract
The effect of amino silane coupling agent on properties of wheat straw boards produced by UF and MF resins, was investigated in this study. For producing the straw boards small particles of straw were used . The results showed that adding 2 and 5 percents of silane had significant effect on improvement ...
Read More
The effect of amino silane coupling agent on properties of wheat straw boards produced by UF and MF resins, was investigated in this study. For producing the straw boards small particles of straw were used . The results showed that adding 2 and 5 percents of silane had significant effect on improvement of boards properties. This improvement might be due to surface treatment of wheat straw particles with silane coupling agent by increasing the bondability between straw particles and resin. The more amine groups in Melamine Formaldehyde resin compare to urea formaldehyde resin , lead to an improvement in bending strength and thickness swelling.
Research Paper
Amir Eshraghi; Habib alah Khademeslami; Amir Nourbakhsh; Behzad Bazyar; Mohammad Talaeipoor
Abstract
In this study, aspen chips with OCC (Old Corrugated Container) were used in particleboard production and samples were prepared at two different levels of resin contents (%9 and %10) and three levels of combination:
1- %25 OCC +%75 aspen, 2- %50 OCC + %50 aspen, ...
Read More
In this study, aspen chips with OCC (Old Corrugated Container) were used in particleboard production and samples were prepared at two different levels of resin contents (%9 and %10) and three levels of combination:
1- %25 OCC +%75 aspen, 2- %50 OCC + %50 aspen, 3- %75 OCC +%25 aspen. Indeed in this study these two mentioned factors are variable and other factors such as press temperature: 165 ºC, press time: 5 minute, mat moisture %12, board density 0.75 g/cm3 and press pressure 30 kg/cm2 were constant. After the boards were manufactured according to DIN-68763 standard, were undergone different tests such as: bending strength, modulus of elasticity, internal bonding strength and thickness swelling after 2 & 24 hours immersion in water. The results indicate that second ratio(%50 OCC and %50 aspen chips) is proper for bending applications and the first ratio(%25 OCC and %75 aspen chips) is proper for tensile and thickness swelling applications. Therefore, applying the OCC more than %50 in manufacturing combination; result in decreasing the physical and mechanical properties. Moreover the results show that when the resin content increases, the board features improve.
Research Paper
Composite wood products
Hassan Zyaei; Habib alah Khademi eslam; Behzad Bazyar; Noraldin Nazarneghad
Abstract
The aim of this study was to determine effect of coupling agent contents on the thermal properties and nanoclay dispersion of reed flour /polypropylene /nanoclay composites. For this purpose we considered wood flour 40% fixed maleic anhydride in two levels (5% and 10%) and nanoclay (Cloisite 10A) in ...
Read More
The aim of this study was to determine effect of coupling agent contents on the thermal properties and nanoclay dispersion of reed flour /polypropylene /nanoclay composites. For this purpose we considered wood flour 40% fixed maleic anhydride in two levels (5% and 10%) and nanoclay (Cloisite 10A) in three levels (0, 1 and 3%). The materials were mixed in an internal mixer with 175 oC, 60 rmp for 10 minutes and then the specimens were fabricated by injection molding method. The clay structure and dispersion processes have been studied by X-ray diffraction. Thermal characterizations of the nanocomposites were carried out using Differential Scanning Calorimeter (DSC). The results revealed that Enthalpy, Crystallinity and Crystalline temperature of composites were increased by adding up of coupling agent and nanoclay (in some levels) contents. The XRD patterns show the exfoliation structure of nanoclay that indicated on a good dispersion of clay in polymer matrix, which turn in a reason for increasing thermal properties.
Research Paper
Nader Maili; Mohammad Talaei; Habib alah Khademi eslam; Behzad Bazyar
Abstract
In This Study,Effect of Enzymatic Deinking on Mechanical Strength of old newspaper was investigated .The protocol for the enzymatic treatment of old newspaper on a laboratory scale using cellulase and combination of callulase:lipase was developed as an effective method for paper recycling.
The deinking ...
Read More
In This Study,Effect of Enzymatic Deinking on Mechanical Strength of old newspaper was investigated .The protocol for the enzymatic treatment of old newspaper on a laboratory scale using cellulase and combination of callulase:lipase was developed as an effective method for paper recycling.
The deinking conditions of pulping consistency of 4% with the pulping time of 2/5 min.temperature 20 and 50 C.at neutral PH.
The study focused on analyzing the effects of enzyme treatment on mechanical strength of old newspaper.
The results showed that enzymatic treatment increases the mechanical strengths of the treated pulp compared to the control pulp.Also, the effect of combination of cellulase and lipase on improvement of mechanical strengths of pulp is more than cellulase treatment alone.
Research Paper
Management and Economics wood
Mehdi Modirzarea; Sayed khalil Hosseini hashemi; Amir Nourbakhsh; Vahid Safdari
Abstract
In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press ...
Read More
In this study the effect of white and brown-rot fungi on durability and hardness characteristics of Bagasse/Polypropylene composite was evaluated. The test specimens were prepared using Bagasse fibers (38%), Polypropylene (60%), and maleic anhydride (2%) according to respective standard and by hot press method. Then specimens were exposed to white (Coriolus versicolor) and brown-rot (Coniophora puteana) fungi according to BS 838:1961 standard and Kollescale method at 8, 12 and 16 weeks. After that, superficial damage, weight loss, and hardness strength of samples were determined. The results showed that superficial damage of brown-rot fungus was lower than white-rot fungus. The weight loss of white-rotted samples were significantly (P<0.05) higher than brown-rotted one, but the hardness of white-rotted samples was a little higher than brown-rotted one. Totally by increasing of time the severity of decay increased.
Research Paper
Pulp and paper
Iman Akbarpour; Hossein Resalati
Abstract
This research was accomplished in order to investigate the replacement of organic complex of Glanapone Stab with sodium silicate on optical properties of hardwood CMP pulp bleached by hydrogen peroxide. The highest brightness of 65.5% and the lowest yellowness of 21.6% was attained at silicate-free ...
Read More
This research was accomplished in order to investigate the replacement of organic complex of Glanapone Stab with sodium silicate on optical properties of hardwood CMP pulp bleached by hydrogen peroxide. The highest brightness of 65.5% and the lowest yellowness of 21.6% was attained at silicate-free followed by replacement of 0.7% and 1.5% Glanapone. But the highest opacity 98.2% was gained using 0.5% glanapone. The brightness of paper increased to 68.1% and the yellowness decreased to 20.8. by adding of glanapone consumption from 0.4% to 0.5% in blended with 0.7% sodium silicate. At higher levels than 0.5% glanapone, the brightness of paper decreased and the yellowness increased. Using Higher levels of 1 and 1.5% glanapone in blended with 0.7% sodium silicate resulted the highest opacity 97.9% and 98%, respectively. Increasing of peroxide usage up to 5% at two different states of silicate-free and silicate-containing with glanapone resulted in the paper with higher brightness and lower yellowness and opacity. CMP pulps bleached at 120 minutes resulted the highest brightness of 71.1% and the lowest yellowness of 18.3% at silicate-containing state with glanapone. Maximum opacity of 98.3% and 98% were shown at bleaching time 30 minutes at two states silicate-free and silicate-containing state with glanapone, respectively. In this research with regard to optical properties in relation to paper produced from CMP pulp bleaching at two states silicate-free and silicate-containing with glanapone,it can be said that possibility of producing the paper with similar optical properties or even better using 0.7% or 1.5% at silicate-free is in compared to conventional hydrogen peroxide bleaching. Also, we could produce the paper with higher brightness along with lower yellowness and similar opacity followed by bleaching time of 120 minutes and hydrogen peroxide 5% in combination of 0.7% sodium silicate with 0.5% glanapone in compared to higher consumed values of sodium silicate.
