Iranian Journal of Wood and Paper Science Research
Year:2018 | Volume:33 | Issue:2 (63) |Papers Count:16

The application of corn stalks in the production of oriented strand board (OSB) is investigated. Corn stalks strands were produced in three sizes of 50, 75 and 100 millimeters in length and dried to reach 2% moisture content. Oriented strand boards were made using either urea formaldehyde, melamine formaldehyde and phenol formaldehyde resin, and two press temperatures of 175 and 185 ° C. OSB boards using poplar wood strands, 100 millimeters long were also produced as control samples. The results of strength measurements of the boards were statistically analyzed using factorial experiment and completely randomized block design. The grouping of the averages was based on Duncan Multiple Range Test. The results showed that the effect of the resin type on the flexural properties and internal bonding of the boards is statistically significant and boards produced using phenol formaldehyde resin exhibited the lowest modulus of rupture, modulus of elasticity and internal bonding strength. However, the adhesive type did not statistically influence the physical properties. The strand length also statistically influenced the board strength properties and boards made using poplar strands showed higher strength compared to corn stalks strands. The thickness swelling of the poplar OSB was almost twice the values of corn stalks OSB and the water absorption of these boards was lower than of corn stalks OSB. Press temperature adversely affected the modulus of rupture and elasticity, but higher press temperature improved the internal bonding strength. Higher press temperature increased the physical properties of the boards.

The objective of this study was the investigation of the effect of adding the wollastonite nanoparticles (casio3) to the water based acrylic coating on fire resistance capability and adhesion strength of coating. The nano wollastonite at the dosage of 0. 5, 1. 50, and 2. 5 wt% weas dispersed into the coating. Ultrasonic device was used to stabilize the nanoparticles on the substrates. The coating process was carried out with and without application of the nanoparticles on the surfaces of spruce and sycamore wood samples and their properties comprising the fire resistance and the adhesion strength were measured. The results showed that adding nano wollastonite to the acrylic coating at the weight percent of 2. 5% (w/w) had the significance effect onto the fire resistance of the samples. In particluar, the effects was observed in case of the delay time of the ignition of the spruce and sycamore samples with the improvement values of 258 and 184% compared with the control samples, respectively. Furthermore, the investigation of adhesion strength of coatings to the surface indicated that the application of nano wollastonites improved the strength properties of coatings. The highest value of this properties was observed in the highest dosage of wollastonite nanoparticles. It should be noted that the performance of nanocomposite coating containing 1. 5 wt% of nano particles on investigated properties was acceptable.

Due to the unstable world economy, in order to survive and create competitiveness in domestic and overseas furniture market, sustainable production and increased quality and quantity of products is needed, However, if attention is not paid on this issue, the possibility of competitiveness in regional and international markets will d eteriorate. Therefore, in this study, with cooperation of experts and industry manufacturers’ expertise the determental ination and ranking of factors affecting classic furniture was determined using Analytical Network Process (ANP) and DEAMATEL techniques. Five main and 17 sub-ind parameters are examined in this study and by using analytical network process, the importance of prioritizing criteria was determined and cause and effect relationships between indicators was evaluated by DEAMATEL techniques. The results showed that, the main indicators of production and sales management, quality assurance, design style and creativity have the highest normal weight and the sub-indices of the modernity of machines and technology, reasonable price and Brand longevity respectively, are the three top priorities which impact the competitiveness of classic furniture.

The effect of nano-alumina application on the mechanical and surface properties of HDF made of surface oxidized fibers

The objective of this study was the evaluation of optical, and mechanical properties of chemi-mechanical pulp which was bleached using one and two stage bleaching sequence with hydrogen peroxide and sodium hypochlorite. Also the environmental effects of effluents from bleaching liquor were studied. For this purpose, unbleached CMP pulp produced using mixture of hardwoods was obtained from Mazandaran Wood and Paper mill. Then, the pulps were bleached using P (hydrogen peroxide), H (Sodium Hypochlorite), PH (Hydrogen Peroxide and Sodium Hypochlorite) and HP (Sodium Hypochlorite and hydrogen peroxide) sequences. 60 gr/m2 hand sheets were prepared and the optical, mechanical properties of hand sheets and also the effluent characteristics from bleaching were measured and analyzed based on TAPPI and APHA Standard method. The results showed that when peroxide was applied at the last stage of bleaching, the properties such as tear, tensile and brightness were increased and yellowness was decreased. Generally, the role of single sequence of bleaching using P and two stages bleaching with HP were more effective than single stage H on unbleached pulp. Based on the results, the highest and lowest COD load was related to bleaching effuent of H and PH respectively. Moreover, bleaching liquor of hydrogen peroxide had the highest BOD load and the lowest amount of BOD was related to PH sequence.

In this study, the tensile and dynamic-mechanical properties of composites made using poly-lactic acid polymer (PLA) and high density polyethylene (HDPE) as matrix and sawdust (30%) as reinforcement were investigated. Maleic anhydride bonded with polyethylene (MAPE) (30%) was used to enhance the bonding. The addition of sawdust increased the stiffness of composites while the use of this material reduced the tensile strength of composites. The highest tensile properties (elastic modulus and tensile strength) were related to poly lactic acid/ polyethylene/ sawdust/ coupling agent composites. The addition of natural fibers to both matrices (PLA and MAPE) increased the composite storage modulus compared to pure polymers, while the modulus of storage in pure polyethylene and its composite was higher. Simultaneous use of two polymers at an equal ratio (33. 5% by weight) and saw dust in the composite have generated the stiffness between the composites made with single polymers. The use of natural fibers reduced the mobility of the molecular chain and shifted the temperature of the composite to higher temperatures, which eventually moved the corresponding corners to the right and lower. However, in some cases, the transmission of pixels has not followed the normal process. The addition of the coupling agent (MAPE) improved bonding between two phases in all composites and ultimately increased stiffness.

Cellulosic fines are essential parts of paper making system which imparts remarkable effects on the production process parameters and the quality of final product. In this study, properties of fiber fines prepared from three kinds of pulps including kraft, chemical mechanical (CMP), and recycled (OCC) were investigated. Required amounts of fines were prepared using Valley Beater apparatus. Then the fines were classified into three categories using dynamic drainage Jar (DDJ): fines passing 100 meshes remained on 200 meshes (P100/R200), fines passing 200 mesh remained on 325 mesh (P200/R325), and fines passing 325 mesh (P325). Fines properties including dimension, special hydrodynamic volume, colloidal charge, alkalinity, turbidity, viscosity, and specific area were measured. The results revealed that PH of fiber suspensions tended alkaline concurrently to the decreasing in dimension of fines. Additionally, the colloidal charge of the three types of fines, especially the charge associated with the fines passed through 200 mesh screens and remained on 325 meshes, showed a different behavior compared to those in the same classes with the adverse trend to the viscosity variation. Special hydrodynamic volume is consistent with the dimension and dimensional ratio with the lowest amount of it observed in the recycled pulp fines. Turbidity has a direct relationship with particles size, homogenous distribution and the specific area of the fines The results of turbidity related to the fines passed through 200 mesh size showed different behavior compared to other categories.

Chemical and biological treatment of dye-containing wastewaters is difficult due to the low adsorption level and chemical stability of dyes. Activated carbon is usually used for the adsorption of these materials, but because of high prices and storage problems, researchers tried to find available low-cost materials with high adsorption potential. In this study, bagasse was used for adsorption of Acid Orange7 dye and its capability was examined. Variables were concentration, temperature, pH and treatment time, and the extend of adsorption was examined in different conditions. Then, adsorption isotherm according to Langmuir and Freundlich models was established. The results showed that the adsorption efficiency depends more on pH of solution and less on temperature of the solution. Maximum adsorption of Acid Orange7 dye by bagasse occurred in the first 15 minutes of contact. The study of adsorption isotherm showed that both models are suitable for description of adsorption of Acid Orange7 dye by bagasse. Maximum adsorption of Acid Orange7 dye by bagasse was determined as 18. 56 mg/g. Results of this study showed that bagasse could be used as a low-cost bio adsorbent for the adsorption of Acid Orange7 from aqueous solution.

Stickies are among the major obstacles in paper recycling mills. This substance deposits on paper machine components and initiates break in the paper web as well as loss of end product quality. So, it is necessary to control the stickies and limits its detrimental effects. It is known that cationic polymers as fixing agents can control the stickies efficiently. Therefore, the control of stickies of OCC pulp using a commercial cationic polymer called GL at 0. 4, 0. 8 and 1. 2 percent based on oven dry weight of pulp at pH 4 and pH 5 were investigated. Macro-and micro-stickies, dissolved and colloid substances (DCS), turbidity, and drainage time were measured to evaluate GL efficiency and compared with control sample. The results indicated that GL dosing at 0. 4 and 0. 8 percent in pH 4 and 7 due to flocculation and fixing the stickies onto the fiber caused to decrease in macro stickies, microstickies and DCS while improved the drainage time. However, no efficient performance was observed in controlling stickies at higher content of GL i. e. 1. 2 percent. Generally, it is concluded that with consuming at desired pH and dosage, GL can be used as efficient agent to control stickies in processing of OCC pulp.

With growth and development of the modern societies and achieve towards industrialization of the countries, Use of the water, one of the major concerns is considered. Optimal usage of water resources has special position and considerable, that its result is importance of the reuse of rain's water as a reliable source for supply the consumption water. The purpose of this research was, use of rain's water, in composition with urea formaldehyde adhesive, In order to adjust the final concentration of the adhesive. To prevent damage against rain water equipment, the Lagan system was transferred through the canals constructed at Arian sina factory. Then it was treated with the package at the factory. The results of the FT_IR spectrum, obtained from composition adhesive samples with rain's water and ordinary water, showed that the rain's water increased the number of hydrogen bonds in the adhesive. But based on the t test, the difference between Mechanical strength and physical properties of use of rain's water than to the ordinary water was not significant. Qua that the glue combined with rain's water does not have any negative effect on adhesive properties. Therefore, after research, Arian sina has been saving water consumption by using 14000 liters of water per day, due to the country's limited resources and lack of resources.

Dyes released into waste water due to its toxicity for some organisms results in major environmental pollution problems. The activated carbon (AC) is an efficient adsorbent to remove this kind of pollutants from aqueous phase. Hence, in this research activated carbon was prepared from sound and rotted beech wood by chemical activation method and its adsorption capacity for removal of Rhodamine B dye was assessed. The carbonization and activation steps were performed at single stage with impregnating the substrate by zinc chloride as activating agent and with the ratio of 75, 100 and 125 percent to raw material mass at 400 and 500 º C. The results showed that with increasing the impregnating agent content, the iodine number of ACs from both woods enhanced. The yield of AC from sound wood decreased with increasing impregnating agent while it was not predictable for AC resulted from rotted wood. Scanning electron microscopic (SEM) studies revealed much morphological changes in the surface of rotted wood-AC in comparison with sound wood-AC after treatment with activating agent. Also, raising the activating temperature from 400 to 500 º C enhanced the iodine number. All prepared ACs performed much efficient in removal of Rhodamine B dye from aqueous solution. The maximum adsorption of the dye was obtained for ACs prepared under impregnating ratio of 125 and activating temperature of 500 º C.

One of the drawbacks of utilizing non-forest fast growing species of Poplar as raw materials to produce newsprint in Mazandran Pulp and Paper Mill is fairly low bulk and opacity of produced paper at the yield of 85% (current CMP yield of the Mill). In this research work, the effect of process parameters (cooking yield and freeness) on the optical and mechanical properties of chemi-mechanical pulp was investigated. The chemi-mechanical pulps of poplar was prepared at four various levels of cooking yield, through changing the cooking time, and their properties at different level of freeness were evaluated in comparison with the control sample of Mazandran Pulp and Paper Mill (75% hornbeam and 25% beech). Strength properties of the paper pulps stemmed from the cooking yields of 85. 25% to 90. 4% were higher and more favorable than the control sample. By contrast, the strength properties of the produced paper pulp from the cooking yield of 94. 6% were inferior to prepared paper pulp from the control sample. According to the results, there is the possibility of significant improvement of the strength properties, opacity and bulk of the chemi-mechanical pulps of poplar trough controlling the process parameters like cooking yield and freeness to use it as raw material of newsprint production in Mazandran Pulp and Paper Mill.

This research concentrated on the crosslinking of nanocellulose fibers with BDDE as crosslinking agent and evaluation of some physical properties of the resulting hydrogel. The renewable polymer chains in this study were nanocellulose fiber and hydroxyethyl cellulose. BDDE was used to form crosslink. BDDE is biodegradable compound which has significantly lower toxicity than other ether-bonded crosslinking agents. FTIR, FESEM, swelling capacity measurement and assessment of the thermal properties were performed to evaluate the effect of this crosslinking agent on the physical properties of nanocellulose. Samples with a lower ratio of nanocellulose to hydroxyethyl cellulose due to dispersion in water and lower degree of crosslinking were uaable to affect the swelling capacity. The cross linking in samples with smaller amount of nanocellulose was not sufficient and dispersion in water was limited. However, as the the amount of nanocellulose increased, hydrogels showed acceptable resistance in water and were not dispersed in the water. Among the samples with a higher amount of nanocellulose, increasing the amount of crosslinking agent from 20% to 40% caused the reduction of water absorption due to more crosslink and less presence of available hydroxyl groups in nanocellulose. According to FTIR results, crosslinking was formed samples with high amount of nanocellulose and different amounts of BDDE. By increasing the amount of BDDE, thermal stability and glass transition temperature were increased due to the proper crosslinking between the fibers and forming stronger and more stable structure.