مجله صنایع چوب و کاغذ ایران
سال ششم شماره 1 (بهار و تابستان 1394)

This study was conducted to investigate the feasibility of using waste textile fibers and the effect of nanoclay content on the physical and mechanical properties of a composite made from wood flour and polypropylene. Therefore، wood flour and polypropylene with a weight ratio of 50 to 50 with the textile waste fibers in two levels (0 and 15%)، nanoclay in three levels (0، 2 and 4%) and 3% compatibilizer were mixed in an extruder at temperature of 160°C. Afterwards، the specimens were made with injection molding thechnology. Mechanical properties including tensile and flexural strength، impact strength and physical properties such as water absorption and thickness swelling were measured. The overall results showed that addition of textile fibers significantly improves the mechanical and and weakens the physical properties of the studied composite. The results indicated that the physical and mechanical properties of wood plastic composites except impact resistance، improved with increasing nanoclay content. The results of morphological studies to study the distribution of nanoclay using a range of X-ray diffraction (XRD) showed that the distribution of particles in the polymer matrix is the type of intercalation and by increasing the amount of nanoclay particles، layer to layer distance was increased.

According to the wrong uses of valuable lignocellulos resources in Sistan and Baluchistan provice and needs to raw materials for wooden industrials in this state، determination and prioritize of effective criteria in construction of particleboard factories with using wastes of Tamarisk، Palms and Musa trees are considered as a purpose of this research. There are 7 main criteria and 52 sub-criteria for construction of these kind of factories. Important criteria are; materials and products، environmental، cultures and socials، technical and humans، economic and financial Infrastructure، geopolitical problems and laws. Many methods for determining effective criteria in construction of wooden industrials are introduced، which the «Analytical Hierarchy Process» is one of them. In this method questionnaires are provided and are completed with experts. Results are processed with «Expert Choice» software and the most important criteria characterized. Some of these important criteria are: assurance of offering the base materials (0. 088)، ceaseless work force (0. 055)، transport of base materials (0. 052)، available materials in location (0. 048)، regional economic growth (0. 044)، quality of base materials (0. 042)، facilities of life (0. 036)، cost of base materials (0. 034)، flexibility of factories in change of base materials (0. 033) and profitability and time of investment returning (0. 033).

The properties of catalyzed organosolv pulp obtained from maple juvenile wood were studied. The physical properties of fiber (e. g. length، width، and cell membrane thickness) and chemical composition of maple juvenile wood (e. g. average cellulose، lignin، extractives، and ash content) were determined. The variables were cooking temperature (190 and 200 ºC) and time (40، 60، and 80 minutes). Chemical charge (280 ml methanol، 70 ml water، and 0. 025 mols of Calcium Chloride and Magnesium Nitrate) was kept constant. Pulp screen yields (54. 9 to 60. 91%) and Kappa No. (15. 5 to 18. 4) were measured. Pulp freeness was reduced to 350 ml CSF in PFI mill، and ten 60 g/m2 handsheets were made from the selected pulps. The strength properties of catalyzed organosolv handsheets including tear length (3. 83 to 4. 25 km)، tear index (10. 22 to 12. 81 mN. m2/g)، and burst index (1. 74 to 2. 15 kPa. m2/g) were compared with those of the conventional Kraft handsheets of maple juvenile wood. The least allowed values of the mentioned properties in the Indian (IS) and Japanese international standards (JIS) reveal that while the tear length value is slightly below that of the standards، the values of tear and burst indices are well beyond the given standards، and the environmentally-friendly catalyzed organosolv pulping process (higher yield and lower Kappa No. compared to Kraft) can be recommended to produce paper pulp from maple juvenile wood.

Due to the size and importance of poplar culturing and its role in the West Azerbaijan province economy، evaluation of the poplar value chain is necessary. With drawing up a comprehensive value chain and identify the lacks، setting the value chain in the province were studied. Finally، due to lacks of the value chain، value chain strategy for development was identified using ANP. The results of the calculation of location quotient in the West Azerbaijan province showed that the LQ is equal to 0. 65852. Due to its lower LQ than one، it can be concluded that the poplar costumers in Western Azerbaijan province are less than the country average. The results of the prioritization of criteria affecting poplar value chain development in West Azerbaijan province indicated the most important criterion is the access to wooden raw materials weighing 0. 16. After that the stable supply of raw materials، machinery and equipment، manpower، proximity to local markets، expertise and financial resources are with weights، 0. 132، 0. 123، 0. 116، 0. 105، 0. 102 and 0. 07 respectively. The weights of the other criteria have a little importance in the development of the poplar value chain. Final results of alternatives prioritization showed، the maximum weight is related to particleboard with the 0. 295. The following options are OSB، MDF and HDF which have a weight of 0. 185 and 0. 178 respectively. After the composite wood products is turn of chemical products، namely cellulose، pulp and paper weights 0. 112، 0. 1 and 0. 066 respectively.

Swelling percent is a very important physical property of the final product. Swelling test is timely and needed to cost. Therefore، swelling prediction of particleboard in production during can operate of the process line and consistent quality of production. In this research، variables such as moisture content of particle، the amount of adhesive، press time، press temperature، press pressure and swelling properties of particleboard were collected from Debalkhazae mill. The normalized data was analyzed by artificial neural network and fuzzy systems. Also، swelling percent was predicted by optimal model. The best model of swelling prediction is 5-5 basis of artificial neural networks، and the best function of fuzzy systems is Z-shaped curve membership function. Means absolute percent errors of the predictions are equal 5 and 22 percent، respectively. ANN method has better performance compared with fuzzy systems.

Damage to the harvested log can occur during the felling، delimbing، bucking، skidding، piling، and hauling functions of wood harvesting. A field-based study was performed to determine the amount of industrial round-wood losses associated with most applicable motor-manual tree felling and bucking systems in Gorazbon district in Kheyrud forest northern Iran. Observations were made for motor-manual harvesting systems during the felling and bucking operations. The damages detected were broken down into four groups in felling operations: split damage، stump height، slab damage، and splintering or breakage damage. There were tree types of damage recorded following the bucking operations: split damage، splintering or breakage damage and measurement error or deviation from the desired log dimensions. In the felling operations، splintering or breakage damage and splits were the most frequent types of damage. The majority of woody tissue damage in the bucking process was caused by measurement error. The total losses in industrial round-wood volume were measured as 32. 6 cubic meters (in the felling and bucking operations; were as 86 and 14 percent، respectively). The total losses in industrial round-wood value at the study area were estimated as 196. 6 million Rials (in the felling and bucking operations; were as 85 and 15 percent، respectively).

The aim of this research is study on physical and mechanical properties of wood flour/ Acrylonitrile Butadiene Styrene (ABS) based on effect of SMA as coupling agent (0، 4 phc) and wood flour filler loading (30،40، 50% of total weight) and virgin and recycled ABS. Samples of composites were made by injection molding method and physical tests including long term water absorption and thickness swelling and mechanical tests containing hardness and tensile strength and modulus of them were performed according to ASTM standards method. The results showed that by increasing the amount of wood flour water absorption، water absorption coefficient، thickness swelling، hygroscopic thickness swelling rate، hardness، tensile strength and modulus of composites were increased. Using of virgin ABS in making of composites increased the tensile properties، hardness composites and decreased water absorption، thickness swelling and parameters of them، in long term immersion. Using of SMA in composites decreased hardness of composites.

In this research، the effect of enzyme treatment to modify bagasse soda pulp properties was investigated. Viscozyme enzyme (mixture of carbohydrates degrading enzymes) extracted from fungus Aspergillus aculeatus was added to pulp at different dosages of 0. 5، 1 and 2 IU (based on per gram of oven dry pulp) and reaction times of 0. 5، 1 and 2 hours. Tappi standard was used for preparation handsheets. For comparison handsheets from analysis of variance test and for comparison of the means from Duncan test were used. The results showed that pulp freeness and polymerization degree of pulp decreased as enzyme dosages and reaction times increased. In fact، enzymatic pretreatment by partial fiber fibrillation played the role of a refiner and improved mechanical properties of paper. Enzymatic treatment improved tensile and burst index. Enzyme concentration of 0. 5 IU and 1hr reaction time had the most effect on tensile and burst index. Although higher enzyme concentrations (2IU) decreased strength properties of paper due to declined viscosity، but in comparison with control sample had more strengths.

Synthesis of colloidal silver nano-particles، as well as the effect of combined colloidal nano-silver and hydrothermal modification، on weight and chemical changes of wood particles through spectroscopic FTIR were investigated. Treatment levels were divided in 4 groups namely، control، nano- impregnated، hydrothermal and nano-hydrothermal. Hydrothermal and nano-hydrothermal treatments were separated in two temperatures (150 and 170 °C) and two times (30 and 45 min) with total of 10 treatment levels. Colloidal Nano silver with 100 ppm concentration was prepared. The scanning electron microscope images proved the presence، size and appropriate distribution of colloidal nanoparticles silver in wood particles clearly. With regard to the results، increasing time and temperature hydrothermal treatment had significant effect on weight changes. Also، colloidal nano silver intensified weight loss، that maximum weight loss was measured at 170°C. The FTIR spectra indicated that increase in the temperature and time of hydrothermal treatment، declined absorbance intensities in wave numbers of 3422. 25، 2922. 38، 1740. 55، 1330. 50، 1243. 39 and 1053. 05cm-1 due to breakdown of acetyl groups in hemicelluloses and decrease in hydrophilic sites. These reduction in nano hydrothermal treatment were more obvious than those for hydrothermal.

This research was conducted to determine the effect of heat-treatment with raw cotton seed oil on decay resistance and dimensional stability of beech according to EN113 and ASTM-D1037 standards respectively. The heat treatment with raw cotton seed oil was carried out in the cylinder at the temperatures of 130 and 170oC for 30 and 60 minutes. Oil uptake, density, volumetric swelling, water absorption and weight loss exposed to decay were measured. Oil uptake at 30 and 60 min were determined 10.5 and 13.3 Kg/cm3 respectively. Oil-heat treated samples at 30min and 130°C indicated the maximum density with 87.7% increase. According to results, oil-heat treatment improved water repellency and dimensional stability. Water absorption in 130°C and 60 minutes decreased 76% in comparison with control. Decay resistance of oil soaked samples for 60minutes was 80.2% more than control samples. Oil-heat treatment compared with oil treatment improved decay resistance, this effect was significant at 30 min. The temperature rise of oil–heat treatment at 30 minutes improved decay resistance, but the improvement under same level of temperature with increase time was not significant.

In order to eliminate the harm of formaldehyde from panels bonded with UF resin to environment and human health at the source, the low volatile and nontoxic aldehyde of glyoxyal (G) was chosen to react with urea (U) to prepare the wood adhesive of urea-glyoxal (UG) resin a substitute for urea-formaldehyde (UF) resin. The urea-glyoxal (UG) resin was synthesized under weak acid conditions, and its different properties were measured. Also, the effect of nanoclay on physico-chemical, thermal and mechanical properties of UG resin was investigated. For this purpose, the prepared UG resin was mixed with 1, 2 and 3 wt% nanoclay by mechanically stirring for 5 min at room temperature. The physico-chemical properties (such as SPG, viscosity, solid content and gelation time) and dry shear strength of the prepared resin were measured according to standard methods. Also, the effect of nanoclay on curing temperature of UG resin was analyzed by Differential Scanning Calorimetry (DSC) device. The physico-chemical test results indicated that addition of nanoclay increased SPG, viscosity and solid content of UG resin and decreased gelation time in the prepared resin. Dry shear strength test results showed that increasing nanoclay content from 1 to 3 wt% increased shear strength of UG resin; as the panels containing 3% nanoclay exhibited the highest shear strength value and wood failure percentage. Based on DSC test results, hardening rate as well as enthalpy value of the prepared UG resin was decreased by addition of nanoclay.

In this study chemical composition، fiber biometry، pulp and paper characteristics from Criptomeria japonica wood which has been planted in Gilan province (Pisseson region) were investigated. Mean value of specific gravity and basic density of wood were 0. 376 and 0. 338 gr/cm3، respectively. Also، fiber (tracheid) dimension including fiber length، fiber diameter، lumen diameter and cell wall thickness were determined at 2920، 41. 23، 32. 57 and 4. 41µm، respectively. The chemical composition of Criptomeria japonica wood including αcellulose، lignin، extractives and ash content were analyzed. On average Criptomeria japonica wood has 48. 35 % cellulose، 32. 08% lignin، 0. 988% ash and 5. 64% extractives. The results of this investigation show that on average Pulp yield was 50. 53 totally. With increase in effective alkali from 12% to 18%، pulps yield decreased and show significant differences at 1%. Breaking length of hand sheets made at 12%، 14% and 18% effective alkali were 7. 36، 7. 17 and 9. 14 Km، respectively. It was also observed that burst strengths of hand sheets made at 12%، 14% and 18% effective alkali were 4. 87، 4. 93 and 6. 19 Kpam2/g respectively.

This study was performed to evaluate the leaching rate of copper nanoparticles in combined impregnation-densification treated poplar and spruce wood after accelerated aging. Specimens were prepared by impregnation with 200 and 400 ppm nano-copper suspensions، followed by pre-steam treatment and densification. Impregnation was done in a sealed vessel with 4 bar pressure in 20 minutes. Half of the specimens were oven-dried and steamed at 150°C for 2 hours and immediately densified under the hot press at 170°C for 3 hours to reach to the 33% compression rate. All specimens were exposed to the 6 steps accelerated aging procedure according to ASTM D-1037. Leaching test was performed according to EN84 standard (1997) for a period of 14 days. The leached residues were investigated in the Mineral Exploration and Geological Center by atomic absorption method. Results showed that nano-copper particles in impregnated specimens had no leaching; but the pre-steaming and densification treatments led to leaching the nano-copper particles from the treated wood.

The main purpose of this work is to provide an overview of recent research in the area of cellulose nonmaterials production from different sources. Due to their abundance، their renewability، high strength and stiffness، being eco-friendly، and low weight; numerous studies have been reported on the isolation of cellulose nanomaterials from different cellulosic sources and their use in high performance applications. This work covers an introduction into the nano cellulose definition as well as used methods for isolation of nanomaterials (nanocrystals) from various sources. The rod-like cellulose nanocrystals (CNC) can be isolated from sources like wood، plant fibers، agriculture and industrial bio residues، tunicates، and bacterial cellulose using acid hydrolysis process. Following this، the paper focused on characterization methods، materials properties and structure. The current review is a comprehensive literature regarding the nano cellulose isolation and demonstrates the potential of cellulose nanomaterials to be used in a wide range of high-tech applications.