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Factors of manufacturing sustainability in the papermaking industry were identified and ranked using qualitative analysis and nonparametric tests. Based on a review of the literature on sustainable development and production, seven main factors of economic, environmental, technological, social, human, material and product, and regulations were identified to underpin the manufacturing sustainability in the papermaking industry, as well as some sub-factors. Then, a self-designed questionnaire was developed to take a poll among papermaking managers and experts regarding the effectiveness of the factors and sub-factors in manufacturing sustainability and their status. The factors affecting manufacturing sustainability in the papermaking industry were confirmed by the standard and significance coefficients in the structural equations and the predictive criterion. The cross-validated redundancy index showed that the data were valid enough for prediction. The research factors were ranked by the ordinal average affecting sustainability, current status, and distance to sustainability. The materials and product, environmental, technological, and economic factors had the greatest influence on manufacturing sustainability, and the regulation and human factors had the highest distance to sustainability. To achieve manufacturing sustainability in the papermaking industry, regulations and human factors need to be further studied. Their improvement has potential to achieve manufacturing sustainability.

In this research, the influence of two temperatures (60 and 90°C) and three dosages of sodium hydroxide (5, 7.5 and 10%, based on the dry weight) on hornbeam wood chips alkaline pre-hydrolysis and soda pulping was studied. Soda pulping of both pre-hydrolyzed and control chips were conducted applying constant pulping variables. The effect of pre-hydrolysis on hemicelluloses removal and sodium hydroxide consumption and pulp characteristic including total yield, reject, pulp freeness, kappa number, and pulp strengths were measured and statically analyzed. In case the effect of variable on measured property was statistically significant, then Duncan multiple range grouping of the measured property was arranged. The result revealed that pre-hydrolysis removed almost 4.2% (based on dry wood) of hemicelluloses of the wood and pre-hydrolysis demonstrated easier soda pulping delignification, due to weakening the lignin-carbohydrate bonds and both total yield, reject and kappa number were reduced. Tensile strength index of the pulp produced using pre-hydrolyzed chips war lower and as the dosage of sodium hydroxide increases, the tensile strength index was reduced initiated from the removal of hemicelluloses which is also lower than control pulp, Tear strength index of the soda pulp from pre-hydrolyzed chips was mildly reduced which is anticipated to be the consequence of fiber weakening and fiber breaking during cooked chips defibration. The effect of pre-hydrolysis variables on tear strength was not statistically significant. Based on the result of this study, hornbeam wood can be a potential source of bio-refining based on lignocellulosic material.

This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage times (1.5, 3, 4.5 and 6 months) and 2 moisture content of Bagasse (45% and 55%). According to these variables, particleboards were made. Also chemical properties (pH, acid and alkaline buffering capacity) of Bagasse were determined. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. Then Duncan multiple range test was used for grouping of the averages. The results revealed that with decreasing of Bagasse moisture content, Bagasse sample pH and acid buffering capacity were decreased and increased, respectively. Also bending properties and thickness swelling after 24 hours immersion of the boards were improved. With increasing of storage time, the chemical properties of Bagasse tend to be alkaline, and the minimum of board internal bond strength was obtained in 1.5 month storage time. The physical properties of boards were improved with increasing of storage time

The effects of acid copper chromate (ACC) and hydrothermal treatments were determined relative to the hardness, decay resistance, and dimensional stability of poplar wood. Test specimens, prepared from poplar wood (Populus nigra L.), were first heat-treated under saturated steam in a digester and then impregnated with ACC solution and by a long-term (21 days) dipping technique to reach complete saturation. Impregnated specimens were exposed to white-rot fungus (Trametes versicolor) for 14 weeks, using the Kolle flask method. The weight loss and Brinell hardness were determined after impregnation, thermal treatment, and exposure to T. versicolor. The combination of thermal treatment and ACC preservative on the poplar wood showed improved hardness and decay resistance properties of wood, depending on the treatment time and temperature. The highest weight loss (37.78%) was observed for control specimens, and the lowest (3.03%) occurred in 1% ACC-treated specimens. The highest Brinell hardness on a tangential surface was observed in 1% ACC-treated specimens (6.45 kN), and the lowest was noted in the specimens heat-treated at 130 °C and 180 min (0.52 kN).

Extracted wood samples of Fagus orientalis with different solvents were analyzed for their antifungal activity against white-rot fungus (Trametes versicolor) in an agar plate. The most active extract was analyzed for its antioxidant activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method, and the chemical composition were analyzed using gas chromatography-mass spectrometry. After the solvent removal of extractives, especially using chloroform (Chl) and Chl-water mixture, losses in the resistance of beech wood had occurred. However, Chl extract was found to be the most active antifungal agent, and the weight loss (30.38%) of specimens after 14 weeks of incubation was higher than that of other extracted specimens. At the concentration of 0.016 mg/mL, the highest activity observed was by Chl extract (89.45%), which was lower than the value of vitamin C (96.63%) at the same concentration. The lowest weight loss values obtained from the decay test were 0.35% and 0.64% for ethanol and ethanol-water extracted beech wood samples, respectively. The highest weight loss values were 30.38% and 23.98% for Chl and Chl-water extracted samples, respectively.

The effect of thermal-treatment severity of wood on the mechanical and morphological properties of wood plastic composites (WPCs) was investigated. Wood chips were first heat treated at 120, 150, or 180 ºC for 30 or 120 min under saturated steam in a digester. The composites were composed of thermally treated and untreated wood flour, polypropylene, and a coupling agent, produced by melt compounding and then injection molding. The thermal-treatment of the beech wood improved some mechanical properties of the WPCs, depending on the treatment-time and temperature. The SEM micrographs of the composites showed that the outer surface of the wood fiber was coated by a section of amorphous lignin. The SEM images showed that the WPCs produced from the wood treated at 150 ºC for 30 min had considerably fewer holes and many broken fiber ends embedded in the polymer matrix, indicating better compatibility between the wood flour and the polymer matrix. Based on the results of the mechanical testing of the WPCs, the optimum thermal-treatment for WPC production was 150 °C for 30 min.

Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at 175 C and the soda pulping time was selected at 120 minutes and the soda-ethanol pulping times were 120 and 180 minutes. The highest accepted pulping yield at 58.54% was reached using soda pulping on poplar wood and the lowest yield (49.29%) was related to soda-ethanol pulp produced from beech wood applying 180 minutes pulping time. The accepted yield of soda-ethanol pulping was low, but the kappa numbers of these pulps were almost 20 units lower than soda pulps. The strength properties of soda-ethanol pulps were superior to soda pulps and the difference was statistically significant at 99% confidence level. The results of this study indicated that the delignification of soda-ethanol pulping process is faster than soda pulping from the selected hardwoods especially poplar wood.

AbstractAmong the forest diseases, fungi are the most important factors that cause irreparable losses to the wood in standing trees and logs. Fungi are the cause of contamination and decay of trees and timbers in forest or in the stock of factories. Decayed woods are one of the biomass resources and a great amount of decayed woods in the forests are not viable. In this study some experiments were conducted in order to investigate the effect of Coriolus versicolor decay on compounds obtained from beech wood (Fagus orientalis L.) pyrolysis and preparation of various and valuable chemicals. Separation and identification of chemical compounds in sound wood and decayed wood of beech was conducted by using pyrolysis method at 500° C and in nitrogen atmosphere. Separation and identification of extracted chemical compounds was carried out using sailylation of these compounds by N, O-bis (trimethylsilyl) trifluoroacetamide and also using Gas Chromatography and Mass Spectrometry method. Totally, 23 compounds were identified in sound beech wood which most of these compounds, in this temperature, are related to 2,6-dimethoxyphenol and 3-hidroxy-4-methoxy benzoic acid; and 31 compounds were detected in decayed beech wood that most of them are related to Cyclononasiloxane octadecamethy and 4-(3,4-Dimethoxybenzylidene)-1-(4-nitrophenyl) and also 17 compounds were detected the same in sound and decayed wood.

In this research the effect of softwood cellulose fibers surface characteristics on mechanical properties of cellulose fibers / polypropylene composite (W.P.C) was studied. The fibers were refined to modify the surface characteristics and reach four different freeness levels (11, 14, 17 and 21 °SR). Then the fibers were mixed with polypropylene using pre-determined levels of 20% fibers and 77% polypropylene and 3% MAPP and samples were made. The results revealed that refining the fibers will change the strength of the composites. Statistical analysis should that the impact of the different freeness levels statistically influenced the strength at 99% confidence level. The highest strength levels were reached using fibers with the freeness level of 14 oSR.

The influence of different dosages of surfactant and soap in the deinking of wastepaper is investigated. The results showed that the dosage of 0.25% soap generated highest brightness and lowest opacity. However, the dosage of 0.75% soap produced highest tensile and burst strength and 0.5% soap produced the lowest spec (dirt) index. In the case of surfactant application, the dosage of 0.75% surfactant produced highest brightness and 0.5% surfactant generated lowest opacity. Application of 0.5% surfactant showed highest tensile and burst strength and lowest dirt index. The combined effect of both chemicals showed that the combined dosage of 0.75% surfactant and 0.25% soap produces highest brightness but the dosage of 0.25% surfactant without soap produced lowest opacity. Highest tensile and burst strength was related to pulp deinked using 0.5% surfactant and 0.75% soap. The results indicated that the combination of 0.75% surfactant and 0.25% soap generated highest brightness which the important property of the writing and printing paper. The highest tensile and burst strength was measured in deinked pulp produced using 0.5% surfactant and 0.75% soap.

The effect of lamination and adhesive coverage rate in layered products made from Poplar wood was studied The effect of lamination and adhesive coverage rate in layered products made from Poplar wood was studied by non-destructive free vibration test. 120 samples with nominal dimensions of 2.5×2.5×45 cm without any obvious deficiencies were selected and free flexural vibration in free-free bars were performed for testing them. Samples were longitudinal cut in three thinner tangential layers and jointed together again using Poly Vinyl Acetate glue. The specimens were divided into four groups according to adhesive coverage rates, which one group was fully glued and 3 groups were carrying some glue deficiencies in different rates. Manipulated samples were tried again in above mentioned test. Results indicated that shear moduli compare to modulus of elasticity is a more sensitive parameter to evaluate glue efficiency in laminated beams but concerns remained due to blind points in flexural vibration nondestructive method.

In this investigation, the surface chemical properties of the beech wood layers were characterized and the impact of drying condition on the strength of the bond was examined. Defect free beech logs were harvested and then the layers were prepared. The moisture content of the specimens were adjusted at 30, 40 and 50% (dry basis) and then the specimens were air dried under the environment of 30% relative humidity and 21ºC to reach the equilibrium moisture content of about 10% (dry basis). The pH and buffering capacity of the surface layer and the layer 0.5 mm underneath the surface were measured. The dried specimens were bonded using urea-formaldehyde resin and the tensile strength and wood failure were measured using relevant ASTM method. The results showed that as the moisture content prior to air drying was increased, the tensile strength was reduced, but the effect of this variable on tensile strength was not statistically significant. However, the effect of moisture content on wood failure was statistically significant at 99% significance level. The effect of the pH of the under layer on both tensile strength and wood failure was statistically significant at 95%. As the moisture content of the wood increased, the pH of the surface layer increased and the strength of the bond with urea-formaldehyde resin was deteriorated. At higher initial moisture of the wood, the alkaline buffering capacity of the surface layer was lower and its effect of the strength was not statistically significant, but it was significant on wood failure at 99% level. The alkaline buffering capacity of under layer was also changed and statistically affected the bond strength and wood failure at 95% level. The higher alkaline buffering capacity of the under layer adversely affected the tensile strength of the bond. The lowest acid buffering capacity was measured from specimens with 40% initial moisture content and as the acid buffering capacity was increased, the tensile strength was reduced and the wood failure was higher. The impact of surface layer acid buffering capacity on tensile strength was on statistically significant, but on wood failure was statistically significant at 99% level.

The influence of fiber lignin content and the dosage of coupling agent on the strength and physical properties of cellulosic fiber-polypropylene composite were investigated. The old corrugated container (OCC) fibers were delignified using sodium hydroxide to reach the lignin content of 2.7, 3.78, 5.26 and 7%. Fibers were compounded with polypropylene by extrusion process using 20% fibers and 77% PP and the extrudate was cooled and grinded to fine granulates before injection molding. MAPP coupling agent was applied at three different levels (1, 2 and 3 percent based on the total weight of the composite). The strength properties of the composites were measured using relevant ASTM test methods and the results were statistically analyzed using factorial experiment under complete randomized design. The impact of fiber lignin content of flexural strength of composite was statistically significant at 98 percent significance level and the lowest and highest values of flexural strength of composite were measured at 3.78 percent and 7 percent lignin content of fiber. The interactive effect of fiber lignin and MAPP on the tensile strength and flexural modulus of elasticity of the composite showed that at lower values of lignin and higher dosage of MAPP, these properties are 38.7 and 3438 MPa respectively. Other strength values of the composites were also improved and at lower content of lignin and increaing dosages of the MAPP, the impact strength of the composites was increased from 52.82 J/m to 60.26 J/m.

Canola straw can be used as a raw material for the production of chemimechanical pulp (CMP). In this work, chemimechanical pulp was first produced from canola straw, and then the bleaching performance of the produced chemimechanical pulp was investigated under different conditions (dosages of NaOH and Na2SO3, time, and temperature). The results showed that the yield of chemical pretreatment in the CMP process varied between 57.6% and 64.9%, while the total yield of the process was between 54.1% and 61.9%. Subsequently, the CMP pulp produced via applying 4% NaOH and 8% Na2SO3 at 145 °C for 15 min was bleached with H2O2. The results showed that pulps bleached via applying one stage of 3% H2O2, 3% NaOH, 6% sodium silicate, 0.5% MgSO4, and 0.3% DTPA for 150 min possessed the highest brightness of 60.8% ISO, which is suitable for container board production.

The influence of reinforcing fibers (old corrugated container fibers called OCC) and addition of foaming agents (Azodicarbinamide and sodium bicarbonate) on density, strength properties and dimensional stability of OCC fiber/polypropylene composite were investigated. Conten of reinforcing fibers constant at 20% and the content of either foaming agent varied as 3, 5 and 7%. Strength properties including MOR, MOE, maximum tensile strength and modulus as well as izod impact strength were measured. Water absorption after 2 and 24 hours soaking in distilled water at 23±2 ºC were measured. Foaming agent decomposition caused some chemical residues in composite and the diffusion and penetration of polymer into the fibers structure led to increase in the density from 839.2 kg/m3 for pure polypropylene to 919.2 - 947.9kg/m3 for the composite, MOR and MOE also increased by the addition of foaming agent and the reinforcing fiber. The effect of 5 or 7% sodium bicarbonate was statistically significant and it improved the properties of the composite. Similar results were obtained for tensile strength and the modulus. Reinforcing fibers and foaming agent caused higher impact strength of the composite. Water absorption of the composites was higher than pure polypropylene.

The impact of Multi Wall Carbon Nano Tubes addition on mechanical properties, water absorption and thickness swelling of polypropylene/old corrugated container (OCC) fiber composites was investigated. Polypropylene/ OCC fiber composite was prepared using 30% OCC fiber, 67% polypropylene and 3% MAPP. Three levels of multi wall carbon nano tubes (1, 2, 4% based on the weight of fiber/polypropylene/MAPP mixture) were added. Composite compound was prepared using a Haake mixer and the test samples were extruded. The results of strength measurement indicated that when 1 or 2% multi wall carbon nanotubes were added, Izod impact strength and flexural strength improved. Higher flexural modulus of elasticity was reached as either 2 or 4% multi wall carbon nano tubes was added. The performance of 4% multi wall carbon nano tubes on flexural modulus of elasticity was superior. Lower water absorption and thickness swelling levels were observed, as 1% multi wall carbon nano tubes was added.

Licorice root residue, a non wood lignocelullosic raw material produced following extraction process was investigated for medium density fiberboard production. MDF was produced utilizing fiber generated applying three steaming times (15, 20 and 25 minutes) at 170 °C steam temperature. The fibers were blended with 10 or 12 % urea formaldehyde resin and then the fiber mats were pressed for either 5, 6 and 7 minutes. Eighteen combinations of variables were obtained and for each combination, three boards and a total of 54 were produced. The anatomical characteristics of the roots and physical and mechanical properties of MDF including bending strength and modulus of elasticity, internal bonding and thickness swelling after 2 and 24 hours immersion in water were measured. The results revealed that the average fiber length and diameter of the root fibers were 1.02 mm and 11.63 µm respectively. The maximum bending strength , modulus of elasticity, internal bonding of the boards produced using fibers generated after 20 minutes steaming time, 7 minutes pressing and 10% resin were measured as 5.291 MPa. 559.4 MPa. and 0.1245 MPa., respectively. The minimum thickness swelling after 2 and 24 hours immersion in water of the above mentioned boards were 31.6% and 34.12% respectively. The results indicated that the fiber produced from licorice root can be used as a partial substitute in MDF production.

The impact of nanoclay addition on the properties of polypropylene/ OCC fibers/ nanoclay Composite was investigated. Composites were prepared using 67% polypropylene, 30% OCC fiber, 3% MAPP and three dosages (2.5, 5, 7.5% based on total weight of PP/OCC/MAPP) of nanoclay. Premix- melting of nanoclay and polypropylene was used to add nanoclay to the composite mixture. Pre-mixed nanoclay/ polypropylene was melt-mixed with OCC fibers and MAPP and then test samples were made using this compound. The results revealed that addition of nanoclay to polypropylene/OCC fiber composite reduced flexural strength , tensile strength and notched Izod impact strength, but the flexural modulus and tensile modulus of final composite were improved significantly. The influence of nanoclay addition on flexural strength and tensile modulus of composite was statistically significant at 99% level whereas its effect on tensile strength was statistically significant at 95%. However, the effect of nanoclay on both flexural modulus of elasticity and impact strength was not statistically significant. The addition of nanoclay to the composite reduces the bonding between polypropylene and OCC fibers. In the case of notched Izod strength, nanoclay particles generated stress concentration point within the composite structure initiating easier failure. Water absorption after 2 and 24 hours immersion was reduced.

The effect of laboratory refining on de-inking potential of inkjet printed handsheets was investigated. Pulp samples containing 80% short fiber and 20% long fiber were beaten in a PFI mill to reach four predetermined freeness levels of 650 (unrefined), 550, 430, and 340 mL CSF, and then handsheets were made. Handsheets were identically inkjet printed and then de-inked. Results revealed that, at lower freeness value, the brightness of de-inked pulps was higher, but the opacity decreased. The surface roughness of handsheets produced using different refined pulp before de-inking was reduced. Our results showed that refining will impart a positive effect on handsheets’ de-inking potential, and de-inking printed papers produced from pulps refined to lower freeness generated the highest brightness. The results revealed that both tensile and tear strength indices of de-inked pulp were lower. However, the tear strength index of unrefined sample and the tensile strength index of pulp refined to 430 ml CSF were higher than for undeinked samples.

Soda - oxygen pulping of old corrugated container to produce totally chlorine free bleached pulp was investigated. In order to reach the optimum delignification condition; four levels of sodium hydroxide (9, 11, 13, and 15 %), three cooking times (90, 120, and 150 minutes) and two cooking temperatures (120, and 150 ºC) at 6 bar oxygen pressure were studied. Yield and kappa number of pulps were measured. Results showed that the pulp obtained applying 9% sodium hydroxide, 150 minute delignification time and 150 ºC delignification temperature which produced the pulp with the yield and kappa number of 72.44% and 24.72 respectively was suitable for further bleaching. Strength of selected pulp including burst strength, tensile strength, and tear strength indices were measured as 2.27 kPa.m2/g, 29.19 Nm/g and 10.24 mN.m2/g respectively. The pulp was bleached applying 3% H2O2 and 2% NaOH to reach the final brightness of 57.97% ISO.

In order to study the optimum manufacturing conditions of wood sawdust-cement perforated blocks, sawdust of headrige saw was mixed with portland cement type II, and then perforated blocks were molded from this mixture. The mixture ratios of sawdust to cement were selected as 28:72, 35:65 and 42:58, respectively. CaCl2 (Calcium chloride) or MgCl2 (Magnesium chloride) at two levels (3%,5% based on the weight of the cement) were used as additives. The results of physical (thickness swelling after 2 and 24 hours soaking in water) and mechanical (compressive strength) properties of the blocks revealed that varying the sawdust to cement ratio imparted differences in physical and mechanical properties of the blocks. The blocks with sawdust to cement ratio of 42:58 showed the highest compressive strength and blocks with sawdust to cement ratio of 28:72 showed the lowest thickness swelling. It was observed that the type of additive did not impose any significant effect on physical and mechanical properties of blocks. Whereas the effect of MgCl2 level on the properties was significant

The paper industry has taken various steps to address environmental concerns and raw material limitations. Among them, paper recycling has been shown to be a viable option. In this study, the alkaline sulfite pulping of old corrugated containers (OCC) to produce bleachable pulp was investigated. A combination of one of the three active alkali levels (14, 16, and 18%; Na2O, and oven-dry weight of OCC); one of two pulping temperatures (145 and 175ºC), and one of two pulping times (60 and 120 minutes) and sodium sulfite to sodium hydroxide ratio of 30/70 (mol/mol) were examined. After preliminary pulping and evaluation, pulp with a kappa number of 18.3 and brightness of 50.2%, which was produced applying 18% active alkali, sodium sulfite to sodium hydroxide ratio of 30:70, and pulping time and temperature of 120 minutes and 175ºC, respectively, having the yield of 64.0% (based on oven dry weight of washed OCC) and 72.7% (based on original weight of the OCC as received), respectively, was selected for totally chlorine free (TCF) bleaching trials. Brightness, opacity, tensile, and tear strength indices of this pulp were measured as 50.2%, 81.4%, 27.7 N.m/g, and 12.35 mN.m2/g, respectively. Bleaching of this pulp applying 3% H2O2 and 2.25% NaOH at 90 minutes generated bleached pulp with brightness and opacity as 57.1% and 78.2%, respectively. The bleaching yield was measured as 92%. Tensile and tear strength indices of this pulp were measured as 25.1 Nm/g and 12.4 mN.m2/g, respectively.

In an attempt to develop pulping process suitable for small scale implementation, production of bleachable chemi-mechanical pulp from wheat starw is investigated. Four levels (10, 12, 14 and 16% based on oven dry weight of straw) NaOH and three pulping times (20, 30 and 40 minutes) at 95°C pulping temperature were used. After digester yield varied between 64.65 and 71.7% and the total yield after defibration was measured as 54.45% and 62%. Unrefined pulp freeness varied between 708 and 765 ml CSF. Pulps produced applying 10-16% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected from further evaluation. These pulps were refined to about 365 ml CSF in a PFI mill and then handsheets were made for strength evaluation. The apparent density of the handsheets varied between 437-488 kg/m3, tear index between 6.51-7.11 mN.m2/g, and tensile index between 29.2 -30.8 N.m/g. Significant difference at 99% was not observed between the strength of the pulps. Then pulp produced applying 10% NaOH, 40 minutes pulping time and 95°C pulping temperature was selected for bleaching trials. Totally Chlorine Free (TCF) bleaching sequence was used for bleaching the selected pulp. Pulps bleached applying 4% H2O2 and 3.5% NaOH, 3% sodium Silicate, 0.5% MgSO4 and 0.3% DTPA for 2 hours showed the highest brightness of 50.69% compared to 29.2% for unbleached pulp.

Alkaline peroxide mechanical pulping of paulownia wood harvested from exotic tree plantations in northern Iran was investigated. The fiber length, width, and cell wall thickness of this wood were measured as 0.82 mm, 40.3 μm, and 7.1 μm, respectively. The chemical composition including cellulose, lignin, and extractives soluble in ethanol-acetone, 1% NaOH, hot and cold water was determined as 49.5%, 25%, 12.1%, 26.9%, 11.4%, and 8.1% respectively. The ash content of this wood was 0.45%. Pre-washed chips were chemically treated at 70°C for 120 minutes with different combinations of three dosages (1.5, 3, and 4.5%) of hydrogen peroxide and three dosages (1.5, 3, and 4.5%) of sodium hydroxide prior to defibration. Other chemicals including DTPA, sodium silicate, and MgSO4 were constant at 0.5%, 3%, and 0.5%, respectively. The results showed that using a 1.5% hydrogen peroxide and 4.5% sodium hydroxide charge, the brightness of APMP pulp reached 68.7% ISO and higher chemical dosages did not improve the brightness; however, to produce APMP pulp with higher strength, a sodium hydroxide charge of 4.5% was needed. The tensile strength, tear strength, burst strength indices, and bulk density of the APMP pulp produced from 1.5% hydrogen peroxide and 4.5% sodium hydroxide were measured as 15.5Nm/g, 6.54mN.m2/g, 0.56kPa.m2/g, and 3.47cm3/g, respectively. The resulting pulp was bulky and is suitable for use in the middle layer of boxboard to provide the desired stiffness with a lower basis weight.

Corrugated board is considered as a valuable community for packaging at both international and domestic markets. Therefore for the development of corrugated board industry in Iran and to understand the variation in demand for this product, it's necessary to identify the consumption and production patterns as well as the most important and effective variables influencing it's status. Then the demand & supply for corrugated board can be forecasted. In this study, the dynamic econometric model has been used to demonstrate simultaneous relationship between supply and demand. Coefficients of the model were estimated using 3sls method with the time series data from 1981 to 2007. The results indicated that in the demand function, intercept, price, GNP in previous period, population, CPI, industrial added value(Iav), production index of large-scale industries(PILSI) and the war dummy variables are significant at 0.05 level. In the supply function, intercept, production quantity in previous period, inflation rate, corrugated board price-raw material price ratio in previous period, import quantity in previous period, cost price all in previous period and subsidy dummy variables are significant at 0.05 level. Results indicate that the mentioned variables influence consumption and production, simultaneously. The results of projection also demonstrate that corrugated board production & consumption will increase into 2012.

Dynamic supply and demand equations for particleboard using a three-stage squares simulation (3SLS) were estimated. Empirical data included annual observations over the period of 1976 to 2006. The stationary character of the data was checked by applying the Augmented Dickey-Fuller (ADF) Test. The results revealed that in the demand function, variables such as particleboard price, the gross national product (GNP) in the previous year (lagged quantity), and the MDF price were significant at 0.05%. In the supply function, variables such as the price of medium density fiberboard (MDF), demand for particleboard in the previous year, the product/raw material price ratio in the previous year, and particleboard imports in the previous year were shown to be significant at 0.05%. Also price, income, and cross elasticities of demand for particleboard were calculated as -0.65, 0.32, and 1.63, respectively, indicating that this commodity is a necessary and normal good and MDF is a substitute for it.

Severe shortage of suitable wood for Medium Density Fiberboard (MDF) production makes it necessary to consider using uncommon and non-conventional raw materials such as agricultural residues. In order to demonstrate the suitability and the potential of two agricultural residues (cotton and corn stalks), laboratory MDF boards were produced. Three press temperatures (170, 180 and 190 ºC) were used. Test samples were prepared from the boards after conditioning at 65% RH and 21 ºC, and all tests were performed according to relevant EN standard methods. The results indicated that the MOR and MOE of boards produced from corn stalks were higher than those from cotton stalks, by almost 25%. However significant difference was not observed for internal bonds of boards. Thickness swelling of MDF boards from corn stalks was lower than cotton stalks. Comparing the results obtained with the strength of boards produced from hardwoods showed similarity between corn stalks and wood, but the strength of MDF boards from cotton stalks was lower. However, the results almost satisfied the EN 622-5;1997 requirement.

Alkaline sulfite pulping of corn stalks was investigated to produce supplementary pulp for corrugating board manufacture. Three pulping temperatures (125, 145, and 165°C) and five active alkali charges (10, 12, 14, 16, and 18%) were used. Cooking time at 30 minutes, Na2SO3/ NaOH ratio at 50:50, and liquor to residue ratio of 8:1 were kept constant. The highest total yield (61.9%) was reached applying the treatment combination of 125°C and 10% active alkali, and the lowest total yield (42.5%) was related to 165°C and 16% chemical. The influence of sodium sulfite/sodium hydroxide ratios was studied applying different ratios (30:70, 40:60, 50:50, 60:40, and 70:30) at constant time and temperature of 30 minutes and 145°C respectively and 14 and 16% active alkali. Pulping condition; 16% active alkali, 30 minutes time, 145°C pulping temperature and varying ratios of sodium sulfite/sodium hydroxide were selected for pulp strength evaluation. The results of handsheet evaluation indicated that 16% active alkali, 30 minutes pulping at 145ºC and sodium sulfite/sodium hydroxide ratio of 50:50 is the optimum pulping condition for corn stalks. Tear, tensile, and burst indices and breaking length of this pulp were measured as 10.53 mN.m2g-1, 62.4 N.mg-1, 3.80 kPa.m2g-1, and 6.07 km, respectively.

Walnut (Juglans regia L.) heartwood extractives were identified and their potential for protection of poplar wood was evaluated. Test specimens were prepared from poplar wood (Populus nigra L.) to meet BS 838:1961 requirements. Samples were impregnated with heartwood extractive solution (1.5, 2.5, and 3.5% w/w in ethanol-toluene), followed by 5 hours vacuum desiccator technique to reach complete saturation. Impregnated specimens were exposed to white-rot fungus (Trametes versicolor) for 14 weeks according to BS 838:1961 applying the kolle-flask method. The weight loss of samples was determined after exposure to white-rot fungus. The highest weight loss (36.96%) was observed for untreated control samples and the lowest weight loss (30.40%) was measured in samples treated with 1.5% extractives solution. The analyses of the extracts using GC/MS indicated that major constituents are benzoic acid,3,4,5-tri(hydroxyl) and gallic acid (44.57 %). The two toxic components in the heartwood are juglone (5.15 %) and 2,7-dimethylphenantheren (5.81 %).

The objective of adding reinforcing fillers, such as natural fibers to plastics is to increase the strength compared with neat plastic and wood. In this research the effect of wood pulp fiber length (short, medium and long), aspect ratio and fiber content (27%, 37%, 47% and 0% (non-reinforced PP)) with 3% maleic anhydride grafted polypropylene on wood plastic composites (WPCs) has been studied. Results showed that increased fiber length or aspect ratio and fiber content increases mechanical properties (tensile strength, tensile modulus and MOE). Impact strength had an inverse correlation with fiber content and fiber length, but fiber content was a much more important factor than fiber length for impact strength. The impact strength of composite of softwood pulps was much higher than wood floor composite plastic. The significant interaction between fiber length and fiber content, and the lack of a specific trend in the treatments made assessment of the effect of fiber properties on MOR difficult.

In the course of enhanced bioremediation, addition of nutrients such as carbon, nitrogen, phosphorous, etc, substrates, electron acceptors as well as vitamins (Thiamin, etc) and veratryl alcohol, increased metabolic activities, will influence the production of enzymes and enhances the deterioration of pollutants. In this study, the effect of 1% (V/V) of nutrients containing various mineral salts, carbon (glucose and malt), nitrogen (casein peptone yeast extract) and some enzyme inducer, such as veratryl alcohol and thiamin hydrochloride on production of laccase, peroxidase and xylanase enzymes by Phanerochaete chrysosporium in bagasse preparation effluent is investigated. The results showed that MSB+MCTV is the most effective additive which causes the highest lignolitic activity of this fungus after 5 to 7 days in case of laccase and peroxidase and 3 days for xylanase, and maximizes the production of the enzymes. The production of these enzymes is measured at 78, 193 and 60 U/l respectively. However, in conditions without additives, the relevant values are 26, 54 and 16 U/l respectively. The relation between different stages of fungus growth and enzyme production and changes in lignin and carbohydrate of effluent after the period of nine days is also investigated.

This study was performed to determine the effect of boric acid treatment upon the decay resistance and mechanical properties of poplar wood. Test specimens were prepared from poplar wood (Populus nigra L.) to meet ASTM D 143-94 and BS 838:1961 requirements. Samples were impregnated with boric acid solution (0.5, 1, and 2% w/w in distilled water) and by a long-term (21 days) dipping technique to reach complete saturation. Impregnated specimens were exposed to rainbow white-rot fungus (Trametes versicolor) for 14 weeks according to BS 838:1961 as applied by the kolle-flask method. The weight loss, compression strength parallel to the grain, and Brinell hardness were determined after impregnation and exposure to white-rot fungus. The highest weight loss (28.60%) was observed for untreated control samples and the lowest (0.63%) occurred in samples treated with 2% boric acid solution. The highest compression strength parallel to the grain was noted in samples treated with 0.5% boric acid and decayed (22.59 MPa) and the lowest compression strength parallel to the grain was recorded in untreated decayed samples (10.42 MPa). The highest Brinell hardness on tangential surface was observed in samples treated with 1% boric acid and decayed (1.32 KN) and the lowest was noted in untreated decayed samples (0.39 KN). The highest Brinell hardness on radial surface was observed in samples treated with 1% boric acid and decayed (1.07 KN) and the lowest was found in untreated decayed samples (0.35 KN).

Neutral sulfite semi chemical pulping of Canola residues has been investigated. Canola residues collected from research farm at Agriculture and Natural Resources, University of Tehran, in Karaj. Chemical composition of Canola residues including cellulose, lignin, extractives soluble in ethanol-acetone and ash were determined using relevant TAPPI standard test methods. Fiber dimensions of Canola residues were also measured. Then neutral sulfite semi chemical pulps were produced from Canola residues applying following conditions: Cooking time at 3 levels(20,40,60min),chemical charge at 5 levels(8,10,12,14,16 %), Cooking temperature was kept constant for all cooks at 175ċ , Na2SO3 to Na2CO3 ratio was 3:1,and liquor to Canola residues at 8:1. Each pulping was repeated tree times. At the end of each cooking, initial defibration was carried out using a laboratory disc refiner. Total yield before defibration and yield after defibration and screened yield were determined. The highest yield (72%) was obtained at treatment combination of and the lowest yield (58.7%) was in treatment of .Both factors, time and chemical charge, had significant effect on yield and increasing these two factors caused lower yield.

The influence of pulping temperature and time on strength properties of bagasse soda pulp was investigated. Two cooking temperatures)175ْC,185 ْC (and three cooking times (20,30,40 minutes) were selected .The other variables were kept constant at 18 % NaOH and l/w=8. Tensile strength, tear strength index and folding endurance of hand sheets measured . Factorial experiment and randomized block design was used for statistical analysis and DMRT was used for grouping the means. The results indicate that, application of intermediate cooking intensity produced better pulp than more intense pulping at highest pulping time and temperature. However, more intense pulping produced better folding endurance and pulp prepared at 30 minutes cooking time showed better folding endurance than pulp produced at 20 minutes. The highest tear index was obtain at 185 ْC and 20minutes and lowest at 185ْC and 40 minutes. Results indicate that undamaged fibers will product highest tear index. The highest folding endurance was produced at 175 ْC and 30 minutes and the lowest at 185ْC and 30 minutes .Increasing pulping time reduced tensile index and the highest and lowest tensile index obtained at 20 and 40 minutes pulping time respectively.

The influence withdrawal strength and bending moment of mortise and tenon joint is investigated. Based on vast application of this type of different length of joint, the effect of tenon lengths (20 , 30, 40, mm) and wood type (beech, alder,spruce) These strength properties is investigated. 9 combination of variables and total of 72 T-shape samples were tested at loading rate of 1.25 mm/min. The combination of variables significantly in fluences the load bearing capacity of joint. Joint produced with tenon lenghts of 30 mm and alder wood showed highest withdrawal strength and the joint produced at the tenon length and beech wood showed highest bending moment so this combination of variables is recommended.

A mild acidic dioxane extraction method was employed to isolate lignin from hardwood bleached chemimechanical pulp (BCMP). The isolated lignin was then purified and undergone elemental analysis. To study the photodegradation behavior, the lignin samples were impregnated onto the Whatman filter papers and irradiated with UV light for various periods. The photolyzed lignin was then recovered and analyzed by 1H-NMR spectroscopy. Phenylpropane-based formula (C9) of CMP pulp lignin and the photolyzed samples were then established with elemental analysis and 1H-NMR spectroscopy data. The results indicated that the benzaldehyde and benzoic acid type compounds were the main photodegradation products of BCMP lignin. The lignin photodegradation probably involved the degradation of phenylcoumaran units. Irradiation also increased the phenolic hydroxyl group content and decreased that of methoxyl groups, due to demethoxylation. The degrees of aromatic ring condensation were increased upon continuing the irradiation time, which imples the formation of condensed structures in photolyzed lignin.

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 170° 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.

Apparent Density of paper is the most effective physical property which directly and indirectly affects most of the strength and optical properties of paper such as tensile strength, modulus of elasticity, light scattering coefficient as well as the bonded area between fibers. Since paper making variables influences the apparent density of paper, in this study, the influence of OCC pulp freeness, and drying conditions are investigated. The influence of three freeness levels of 350,450, and 550 CSF, drying under strain and unstrained, drying temperatures of 100, 150, 200 C and drying pressure of 7 and 10 kg/cm2 are studied. The relationship between paper making variables and apparent density is developed. All measurements of apparent density were analyzed using Minitab 15 and regression model between independent variables was calculated. The results showed that both pulp freeness and drying temperature had the highest impact on apparent density and both factors increased the apparent density. The response of apparent density of the hand sheets dried at 200 ◦C varied considerably and was analyzed thoroughly. Higher pressure increased apparent density of the sheets. The combined effect of variables is also considered. The combined effect of pulp freeness and drying temperature caused lignin softening and delamination. However, the influence of increasing the drying pressure for unrefined and less refined pulp is not significant. Furthermore, for unstrained drying, the influence of freeness on apparent density was more than strained drying. Manufacturing of more desirable quality papers would be possible considering the obtained results and the effect of Apparent Density on paper strength properties.

For the determined of Anatomical, Chemical and Physical characteristics of SAXAUL wood (Haloxylon persicum) from Haresabad-e-Sabzevar research station located in Khorasan-e- Razavi province 4 trees from this specie were selected and cut. Samples transferred to the Chemical laboratory in Alborz-e-Karaj research center for studies. Anova-1 in mstat-c statistical software was used for statistical analysis. Anatomical characteristics measured Fiber length, Fiber diameter, lemun and cell wall thickness 336.22, 13.61, 3.68 and 4.99 micron, respectively. Paper making coefficients were also measured. Mix up coefficient; Flexibility coefficient and Rankle coefficient were 24.72, %27.05 and %2.71, respectively. Chemical characteristics measured cellulose, lignin, alcol-acetone soluble extractives, NaoH 1% soluble extractives, hot water soluble extractives and ash 46.50%, 29.54%, 7.37%, 16.25%, 6.92% and 1.27%, respectively. Physical characteristics measured of density, dry density and critical density 1024.25, 1003.83 and 913 gr. per cubic centimeter.

The property of MDF obtained the mixture of Haloxylon persicum wood (Saxaul) with Carpinus betulus (Hornbeam) at 100:0, 75:25, 50:50, 0:100 ratios is investigated in this study. The results of this study showed that there is significant statistical differences (1%) among combinations of woods for MOR, MOE, IB, thickness swelling after 2 & 24 hours and water absorption after 2 & 24 hours. The bending strength (MOR) of MDF produced of Hornbeam wood fibers was highest and Saxaul wood fibers were lowest. Boards produced from 50% Hornbeam and 50% Saxaul, showed the important of bending strength 57%. The average modulus of elasticity (MOE) of MDF showed significant statistical differences (1%). MDF produced from Hornbeam wood fibers had showed highest MOE and Saxaul wood fibers showed lowest MOB. The result of internal bonding (IB) showed that MDF produced from Saxaul wood fibers possessed lowest IB and Hornbeam wood fibers had highest IB. In other two combinations of Hornbeam and Saxaul wood fibers, there are no significant statistical differences (1%) with MDF produced from only of Hornbeam wood fibers.

Poplar trees are classified as a fast growth trees and because of short rotation period, and suitable technical properties, are considered by pulp and paper making industries. In this study, physical and anatomical properties and pulp and paper of three colons of poplar trees, populous Alba. L. colon 44.9, populous deltoids 69.55, and populous euramerican are investigated. The average fiber length of these three colons were 0.854, 1.148, 1.08 mm. respectively and their average dry specific gravity were 0.386, 0461, and 0.341 g/cm3, and also their average cellulose content were 50.5, 51.5, and 49.5 percent.For Kraft process cooking of the mentioned colons, three cooking time, 1, 2, and 3 hours, 17°C cooking heat, 25% sulfidity, and active alkali at 3 levels, 15, 17.5, and 20% were used. The results show that p. alba, colon 44.9, and p. deltoids colon 69.55 with using 20% A.A and 3 hours cooking time have 53% yield and 18 kappa number.

In this investigation, experimental boards were produced using beech wood particle, mat moisture content gradient at 0,3 and 6%, two press temperature sat 165and 1850 C and two press times at 3 and 5 minutes. 36 sample boards produced and the physical and mechanical properties of those tested.The results indicated that mat moisture content gradient had significantly effected on modified of modulus of elasticity of boards, and with increasing mat moisture content gradient, the MOE of boards increased. Also in 0% mat moisture content gradient, increasing of press time, modulus of rupture and modulus of elasticity decreased. However with increasing mat moisture content gradient, increasing of press time caused of these properties modified.On the other hand an inverse relationship observed between mat moisture content gradient and internal bond of boards that due to of negative effect of increasing of vapor pressure were on resin bond quality in middle layer. But with increasing press time from 3 to 5 minutes, the internal bond of boards increased. The results of thickness swelling measurement indicated that with increasing mat moisture content gradient, the thickness swelling of boards increased. However, when press time increased, the thickness swelling of boards decreased.

Pinus teada, which was planted in Pelembera region, shows promising both in growth rate and adaptability. Even though the fiber geometry of P. teada wood in its native growth region is excellent, but for utilization of this wood in pulping, the knowledge of its technological characteristics especially fiber geometry is required.Two trees of this species were randomly selected from Pelembera forests plantation in Gilan and after felling were cut in smaller bolts and transferred to wood &paper research laboratory, research institute of forests and rangelands. Five cross-sections with the thickness of 15 cm were cut from each tree and the cross-sections were used for selection of samples. Fiber geometry measurement samples were prepared from every five annual rings and from each sample, springwood (early wood) and summer wood (late wood) sample were cut separately. Preparations of fiber geometry samples were according to procedure developed by Franklin (1954) and from each sample the dimension of 30 complete and unbroken trachieds was measured.Trachied length, diameter, cell wall thickness and lumen diameter was measured for different elevation in tree and different growth rings in cross-section.Dimension of 3,00 trachieds were measured totally.Average trachied length, diameter, lumen diameter and cell wall thickness of early wood were measured at 3.65mm, 38.97 mm, 28.94 mm and 3.72 mm respectively. Related values for late wood is as follow: trachied length 3.84mm; diameter, 35.54 /lm; lumen diameter, 22.96 mm; and cell wall thickness, 6.29 mn. Average annual growths were measured at 5.66 mm and late wood percentage at 24.13. Felting, flexibility and runkel coefficients were calculated at 97.96, 73.48, and 26.74 respectively. The result of this study indicates that all measured properties increases with increasing the height of tree and from center (pith) toward outer regions (bark). However all the measured values decreased at highest as well as outer locations.Statistical analysis indicated that the difference in measured properties at different heights of trees from center to the bark is significantly different at 1% level.

This study investigates the effect of maleic anhydride polypropylene (MAPP) addition as a coupling agent at four levels and also the type of cellulosic materials as a reinforcing component on processing and mechanical properties of modified Populus deltoides fiber and flour/ polypropylene composites.The results indicate that the interfacial bond between reinforcing-fiber/ flour and the matrix show great influence on the mechanical properties of composites. Furthermore it has been demonstrated that the addition of coupling agent during processing significantly improves the mechanical properties of fiber/ flour polypropylene composites. The results of this investigation indicates that the highest the mechanical properties of composites are as follow; The mechanical properties of the poplar fiber with 2% MAPP is higher than poplar flour without MAPP, which proves that the addition of functional group C=O acts as a good bonding agent. The notched Impact Izod strength value of poplar fiber with 2% MAPP is less than pure PP. But it is higher than other treatments. The results indicate that the interfacial bond between reinforcing fibers and flour with polymer matrix modified MAPP play a significant role in improving the measured mechanical properties of the composites.

In this research, pulping of rinds from sunflower seeds by soda process is studied. Fiber length was 0.89 millimeters and its chemical content, contained 40.5% Cellulose, 30.5% Lignin, 3.33% Ash and 1.93% Extractives. Conditions of Soda process were three different soda consummations of (Chemical charge) 14%, 16% and 18%. Liquor on rinds ratio, was equal to 6, and period of digestion was 30 minutes. Yield and Kappa number on the best choice of conditions of pulping (165 degree of centigrade temperature and 16% soda consumption) were measured respectively 55.7% and 74.96.Using PFImill, four kinds of pulps with four different free nesses were produced from the proper Pulp and were changed to hand sheets. Study on mechanical strength of hand sheets showed that beating has no effect on tear strength from 30 to 40 SR and it reduces this strength after more beating. Practically, no effect was observed on burst strength and breaking length during beating from 30SR to 60SR. This lignocellulose, agricultural residue is a cheap by-product in Sunflower-oil producer factories. Some of them is as a food for live-stocks and some is burned as a source of energy. Because of this, using rind from sunflower seeds in Paper and other cellulosic industries can be useful.

In this study, annual growth, bark content, fiher dimensions of pine wood (P. eldarica) were measured. Annual ring thickness and bark content 4.95 mm, 12.15% are determined respectively. Fiber length, fiber diameter, lumen cell diameter, cell wall thickness were determined 2.26 mm, 39.63m 29.06 m and 5.28 m respectively. Also felting coefficient 58.59, tear coefficient 36.24% and flexibility coefficient 18.12%were measured. Trend of variations of fibers dimensions indicated that fibers longth increased with increasing tree height from butt to crown. Also this property increased from pith to tenth annuad ring then decreased toward of bark. Cell wall thickness decreased from butt to 2 m. height and then increased. Also cell wall thickness decreased from pith toward bark.

In this experiment the optimum condition of particleboard uom Date palm residues and prosopis (Mesquite) produced in southern part of Iran was investigated. Variable factors as type of raw-material (Date palm and prosopis), resin content (9, 10 and 11 percent) and press time (5, 6 and 7 minutes) and total of 18 combinations of variables were investigated.Other factors such as type of resin (UF), hardner content (2 percent) type of hardner (NH4CI)press closing time (4.5 mm/sec.), board density (0.7gr/cm3) press pressure (30 kg/cm2) and press temperature (160 C) were held constant.All boards were tested according to DIN-68763 standard. The factorial experimental design at completely random blocks test was used. The results of this study could be summarized as follows: Increasing the resin content from 9 to 11 percent increased MOR, MOE and ID and decreased thickness swelling after two and 24 hours immersion in water.The highest internal bond (IB) was related to prosopis (Mesquite) boards made at 5 minute, prass time. As far as production of date plam and prosopis (Mesquite) wood is concerned, the results revealed that the polymerization of resin and wood is better at 11 percent resin content and 5 minutes of press time. Date palm residues are important with treatment process according to reference. NO. One. Shape and dimension of chipped and flaked particles of date palm residues are important, because type and characteristics of species are different, in the mean time, as date palm residues has very high bulk density and specific surfaces than prosopis (Mesquite) which it has inverse effect on both physical and mechanical properties, thus it should be considered during the process of particleboards production.

Laminated beam ( LB.) and laminated veneer lumber ( LVL) manufactured from maple, hornbeam and beech wood is investigated. Three levels of press pressures at 30, 35, 40 kg/cm2, three levels of layer thicknesses of 2, 3, 4 mm and tangential and radial layers are investigated. Bending strength (MOR and MOE) and shear strength were measured according to ASTM 1186 and 905 respectively.The results of this investigation indicated that laminated wood strength of samples produced from hornbeam layers is superior to beech and beech is superior to maple. Statistical analysis of the results showed that the effect of wood species on strength properties is significantly different at 99% level. Press pressure also showed significant effect on strength. Increasing press pressure improved bending properties, but the highest shear strength was observed at 30 kg/cm2. Cutting direction did not influence bending strength and only influenced the shear strength. Even though the initial anticipation was the fact that thinner layer will produce stronger laminated wood. But the results or this study showed that layer thickness did not significantly affect strength properties.

In order to investigate the possibility of utilizing bagasse in high yield pulping, CMP and CTMP pulp from bagasse was compared.APMP pulping process was also investigated. Bagasse fiber length, diameter, lumen diameter and cell wall thickness was measured at 1166mm, 19.63 mLm,7.47 mLm, and 6.09 mLm respectively. Chemical composition was as follow: cellulose 553 %, lignin 20.5 %, ash 1.98% and extractive 2.9 %.The results and comparison of CMP and CTMP pulp are as follow: CTMP pulp yield was 3-4% higher than CMP pulp and the highest CTMP pulp at 80.7% was obtained at 15% NaOH application and 15 minutes chemical treatment time.Breaking length of both pulp was almost equal, but the burst index of CMP pulp was higher and the tear index was lower than CTMP. The highest breaking length of 3.85Kmwas obtained at 15% NaOH and 10 minutes, highest burst index of 4.81 KPa.m2/grat 20% NaOH and 20 minutes and highest tear index at 6.87 mN.m2/grat 15% NaOH and 15 minutes treatment time. Various treatments in APMP pulping reveald the following results: - Two stage pulping yield was almost 6% higher than one stage pulping and addition of H2O2 did not significant improve the yield.- The highest breaking length was related and two stage pulping. But addition of H2O2 in last stage and the lowest breaking length was related and two stage pulping with split application both NaOH and H202.- Even though two stage pulping with the addition of H2O2 in one stage produced highest burst index, but lowest burst index was with the CMP pulps.- Addition of DTPA produced highest brightness and opacity.

به دلیل محدودیت منابع چوبی جنگلی در ایران و معذوریت جایگزین نمودن منابع سلولزی غیرچوبی در تولید کاغذ و مناسب بودن بعضی از این منابع از جمله کاه و کلش برنج برای صنعت کاغذسازی، لازم است خصوصیات کاربردی این ماده مورد توجه و بررسی قرار گیرد به همین منظور از کلش برنج نمونه‌برداری شده وخواص فیزیکی شیمیائی آن تعیین می‌گردد. سپس با انجام پختهای آزمایشگاهی راندمان و سرعت لیگنین‌زدایی و ایجاد آن مورد مطاله قرارمی‌گیرد و در نهایت خصوصیات فیزیکی مکانیکی کاغذ ساخته شده تعیین می‌گردد.