Composite wood products
Abolfazl Kargarfard; Abdolrahman Hosseinzadeh; Amir Nourbakhsh; Ali Fatolahzadeh
Abstract
Particleboard industries are a dynamic industry, that has been established and grown rapidly in Iran. Demand for Particleboard has been increased rapidly due to increase population, thus the possibility of utilization residues from other wood using industries or other lignocellulosic raw materials should ...
Read More
Particleboard industries are a dynamic industry, that has been established and grown rapidly in Iran. Demand for Particleboard has been increased rapidly due to increase population, thus the possibility of utilization residues from other wood using industries or other lignocellulosic raw materials should be investigated. The boards made for this study contained Haloxylon sp. and wheat straw at 0: 100, 75: 25, 50: 50 and 25: 75 ratios as raw material. Samples of all the boards made were tested by the methods described in DIN 68763 standard, to obtain mean values of bending strength, internal bond strength (IB) and thickness swelling.The results of this study showed that there are no significant statistical differences among each combination for MOR and MOE but with increasing the percentage of wheat straw the MOR of boards was found to increase. There were statistical differences among each combination of IB wheat straw had the lowest IB, where as the highest IB were observed on the boards with 100 percent Haloxylon sp.In addition, samples of each type of board were tested for thickness swelling (T.S) after immersion in water for 2 and 24 hours respectively, and the results indicate that there were statistical differences among each combinations and the lowest thickness swelling value was belong to the boards with 100 percent Haloxylon sp. which had the highest IB. It was also observed that the board made of Haloxylon sp. and wheat straw at with 25: 75 ratio had the highest T.S immersion in water after 2 and 24 hours.
Pulp and paper
Jalil Roshanasan; Mohammadreza Dehghani firozabadi; Mohammad Dahmardeh ghaleh no; Saeideh Sharifi
Abstract
The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, ...
Read More
The lignin dissolution in Kraft pulping for wheat straw was studied. Kraft pulping was carried out under the conditions: chemical charge of 18% (as NaOH, based on o.d. bagasse), sulfidity of 25% and liquor to wheat straw ratio of 10:1. Six cooking maximum temperatures of 85,100,110,120,130 and 150 ◦C, were selected and reaction time varied from 0 to 250 min. based on maximum temperature. The Klason lignin, acid soluble lignin, ash and extractive contents of wheat straw were 18.4%, 2.07%, 3.24% and 4.56 respectively.
During alkaline pulping of wheat straw, about 64% and 52% of lignin was removed before reaching to the temperature 100 ◦C and 85 respectively. The values pulp and carbohydrates yield were, about 64%, 58% for 85 ◦C and 61%, 57% for 100◦C.
Composite wood products
Laya Jamalirad; Fereshteh Kor; Farshid Faraji; Sahab Hedjazi
Abstract
In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, ...
Read More
In this research, the manufacture of particleboard using lignocellulosic residues including wheat straw and tobacco stalks mixed with industrial wood chips were studied. The variable factors included the mixture of wheat straw and tobacco stalks with industrial wood chips in four levels 0/100, 20/80, 40/60 and 60/40 (In any combination, according to the desired levels, tobacco stalks and wheat straw were used equally) and the amount of urea formaldehyde resin was at two levels 12 and 14% of the dry weight of the wood chips. The results showed that by increasing the mixture of wheat straw and tobacco stalk up to 60 percent, the physical and mechanical properties of the boards decreased significantly. But increasing the amount of adhesive consumption up to 14 percent had a positive impact on the physical and mechanical properties of the boards and improved internal bonding, bending strength and modulus of elasticity and dimensional stability of the boards. It means that by increasing the use of this type of wastes up to 40 percent with an increase in the amount of UF adhesive up to 14% can be produced the boards with the mechanical properties at standard level.
Pulp and paper
Mohammad Ahmadi; Sahab Hejazi; Kamiar Salehi
Abstract
In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. ...
Read More
In this study, the effect of beating time on morphologic, physical and strength properties of soda and monoethanolamine pulps obtained from wheat straw was studied, in order to optimize the time for beating operation. Beating of the pulps was applied in different time by laboratory jokromill beater. The results showed that rising time of beating leads to increasing the freeness (SR) of pulps and monoethanolamine pulp reached to maximum amount of freeness (SR) in less time as compared to soda pulp. In addition, it is found that monoethanolamin pulp obtained the maximum amount of tensile index (91.3 N.m/g) after 30 min beating time and after that longer time of beating process had no significant effect on increasing the tensile index. About soda pulp it is observed that tensile index was increased significantly by rising the time of beating process and for this kind of pulp, maximum amount of tensile index (87.7N.m/g) was obtained in 50 min beating process. The highest burst index for soda pulp was 5 Kp.m2 which was obtained by 50 min beating process. About mono ethanolamine pulp burst index increased by rising time of beating Process and reached to its maximum amount (5.6 Kp.m2) and after that its amount decreased. Rising the time of beating process led to decreasing the tear index in both of kinds of pulp consist of monoethanolamin and soda pulp. The results showed that mono ethanolamine pulp had the higher yield and better beating ability in comparison with soda pulp which can be caused by better ability for carbohydrates and minerals retaining in monoethanolamin pulp.
Pulp and paper
Afshin Veisi; Saeed Mahdavi; Mohammad Talaeipoor
Abstract
In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals ...
Read More
In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals charge and 10:1 cooking liquor and straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps bleached by TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% (based on oven dry weight of the unbleached pulp) NaOH, 2% H2O2, and 120 min. in bleaching improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured 43.87 Nm/g, 2.18 kPa.m2/g, and 8.46 mN.m2/g, respectively. All the strengths were higher than newsprint paper strength produced by Mazandaran wood and paper and Korean companies.
Physics and anatomy
ahmad saraiyan; soodeh zhand
Abstract
In this study, the effect of boiling water pre-treatment on yield, optical, physical and mechanical properties of NSSC (Neutral Sulfite Semi Chemical) pulp from Zagroos wheat straw (Golestan province) was investigated. Chopped wheat straw was pretreated in boiling water for 30 minutes, water to straw ...
Read More
In this study, the effect of boiling water pre-treatment on yield, optical, physical and mechanical properties of NSSC (Neutral Sulfite Semi Chemical) pulp from Zagroos wheat straw (Golestan province) was investigated. Chopped wheat straw was pretreated in boiling water for 30 minutes, water to straw ratio of 10:1. NSSC pulping was carried out at constant pulping conditions including liquor to straw ratio of 10:1, maximum pulping temperature of 160ºC and 30 minutes pulping time. In order to study the effect of NaOH on strength properties of paper, in some trails only Na2S03 were used. Pulping was followed by defibration in laboratory refiner to reach 380±25mlCSF freeness. Handsheets at 60gr/m² were made from each pulp. The strength properties were determined on the basis of TAPPI standard. Results show that pre-treatment imparted a significant increasing effect on the strength properties of papers such as tensile, burst, breaking length, stiffness and density, except RCT strength. Increasing the chemical charge specially NaOH improved the pulp freeness, yield and handsheet density but the handsheet thickness was reduced.
Composite wood products
Mostafa yahyavi; Abolghasem Khazaeyan
Abstract
Abstract In this study, wheat straw-polypropylene particleboard was produced using a mixture of wheat straw and polypropylene with urea formaldehyde resin and its properties were investigated. The ratio of polypropylene to the wheat straw particles was selected as 10:90, 20:80 and 30:70 percent. Urea ...
Read More
Abstract In this study, wheat straw-polypropylene particleboard was produced using a mixture of wheat straw and polypropylene with urea formaldehyde resin and its properties were investigated. The ratio of polypropylene to the wheat straw particles was selected as 10:90, 20:80 and 30:70 percent. Urea formaldehyde was used at three levels of 4, 6 and 8 percent based on oven dried weight of wheat straw particle. Mechanical and physical properties (modulus of rupture, modulus of elasticity, internal bonding, water absorption and thickness swelling after 2 and 24h soaking in water) of the produced boards were measured. The results showed that increasing polypropylene and urea formaldehyde resin resulted in increasing the bending strength, modulus of rupture and modulus of elasticity of the boards. The results also indicated that water absorption and thickness swelling after 2 and 24h soaking in water decreased with increased polypropylene and urea formaldehyde resin percent. The UF resin content can be reduced in the particleboard as a function of increasing the PP powder.
Soodeh Zhand; Masih Masoudifar; Ahmad reza Saraeian; Ali Ghasemian
Abstract
The purpose of this study was to compare the properties of wheat straw (Zagros sp) collected in Golestan province NSSC pulp under alkaline pretreatment with 1% sodium hydroxide and boiling pretreatment. Wheat Straw pretreatment with 1% sodium hydroxide and hot water at water to straw ration of 10 to ...
Read More
The purpose of this study was to compare the properties of wheat straw (Zagros sp) collected in Golestan province NSSC pulp under alkaline pretreatment with 1% sodium hydroxide and boiling pretreatment. Wheat Straw pretreatment with 1% sodium hydroxide and hot water at water to straw ration of 10 to 1 was conducted at 70ْC for half an hour. NSSC pulping was carried out at constant pulping condition including liquor to straw ratio of 5:1, maximum temperature at 160ºC for 30 minutes. In order to study the effect of sodium hydroxide on strength properties of paper in some cases only Na2S03 was used. After pulping, defibration was carried out by laboratory refiner to reach 380±25ml (CSF). Sixty gram/m² hand sheets were prepared from each pulp. The strength properties were determined according to TAPPI standard. Results showed that with the exception of RCT strength, pretreatment had significant effect on increasing the strength properties of papers and by alkaline pretreatment, brightness of the pulps decreased and tensile strength, burst strength, breaking length, stiffness and density increased. Using chemical pretreatment especially sodium hydroxide resulted in reduction in yield and brightness level and improvement in strength of the pulps.
Fardad Golbabaei; Hossein Hosseinkhani; Reza Hajihassani; Arash Rashnv
Abstract
The main objective of the production of cement - wood products or mineral-bounded composite panels is to combine the mineral components of lignocellulosic materials such as wood and organic particles with inorganic binders such as cement, plaster, etc. Wood cement products which are presently produced ...
Read More
The main objective of the production of cement - wood products or mineral-bounded composite panels is to combine the mineral components of lignocellulosic materials such as wood and organic particles with inorganic binders such as cement, plaster, etc. Wood cement products which are presently produced in most countries possess desirable functional properties such as good weather ability, resistance to atmospheric, biological agents and fire and are lighter weight as compared with other building materials, and provides improved dimensional stability. The flat panels using conventional presses can be produced, and also other products such as concrete blocks, bricks and pieces of different forms can be produced using appropriate frames. Large wood cement- based panels are widely used in construction of residential and commercial buildings. In this research, with respect to the availability of lignocellulosic material (agricultural residues such as rice straw, wheat straw, cotton stalk) in various areas (Gilan, Mazandaran and Golestan)) and the additive material (as calcium chloride), boards with similar structural was produced. Mechanical strength values including static bending strength, modulus of elasticity and elastic bending strength were measured. MSTATC based computer package was used to analyze the data. In terms of the maximum load strength, wood cement board made of poplar wood as the control boards (4.4146 MPa) had the highest mechanical strength followed by cotton stalks (2.463 MPa), wheat straw (1. 6776 MPa) and rice straw (0. 8622 MPa), respectively. In general, the study has indicated the suitability (given the appropriate ratio) of the agricultural residues in construction of wall and warehouse in farm lands.
Mostafa Yahyavidizaj; Asieh khozini; Tagi Tabarsa
Abstract
In this study, Wheat straw particle boards were produced using a mixture of wheat straw andcotton bolls with Urea formaldehyde resin and its properties were reinforced with nanoclay.Cotton bolls and wheat straw particles were mixed at the ratio of 40:60, 60:40 and 80:20percents, respectively. Nanoclay ...
Read More
In this study, Wheat straw particle boards were produced using a mixture of wheat straw andcotton bolls with Urea formaldehyde resin and its properties were reinforced with nanoclay.Cotton bolls and wheat straw particles were mixed at the ratio of 40:60, 60:40 and 80:20percents, respectively. Nanoclay was used at two levels of 0 and 2 percents based on oven driedweight of resin. Control samples were made of Wheat straw particle. Mechanical and physicalproperties (modulus of rupture, modulus of elasticity, internal bonding, water absorption andthickness swelling after 2 and 24h soaking in water) of the produced boards were measured.The results revealed an increase in cotton bolls in the mixture particles, leads to an increase ofthe bending strength, modulus of rupture and modulus of elasticity of the boards. The resultsalso indicated that water absorption and thickness swelling after 2 and 24h immersion in waterdecreased with increase in nano clay and cotton bolls percents.
Soodeh Zhand; Masieh Masoudifar; Ahmad Reza Saraeian; Ali Ghasemiyan
Abstract
In this study the effect of alkaline pretreatment with 1% NaOH on physical, optical and mechanical properties and refining of NSSC (Neutral Sulfite Semi Chemical) wheat straw pulp were investigated. The wheat straw (Zagros Sp.) was obtained from croplands Golestan province. Splinted wheat straw was pretreated ...
Read More
In this study the effect of alkaline pretreatment with 1% NaOH on physical, optical and mechanical properties and refining of NSSC (Neutral Sulfite Semi Chemical) wheat straw pulp were investigated. The wheat straw (Zagros Sp.) was obtained from croplands Golestan province. Splinted wheat straw was pretreated with 1% NaOH(on the basis of OD weight) at 70 degrees for 30 minutes. The main pulping was performed at 160 ˚C with the fixed ratio of 5:1 Na2S03 and NaOH. After pulping defibration was done by lab-refiner to 380±25ml (CSF) and total yield and changes in Kappa was determined. Hand sheets of 60 gr. /m² were made on the basis of TAPPI standard and physical, optical and mechanical properties determined. The results show that alkaline pre-treatment has a significant effect in increasing of physical, optical and mechanical properties. Calculating primary freeness of pulps indicates that by increasing chemical compounds and NaOH, freeness decreases and that by increasing chemical compounds paper density increases, whereas yield, caliper and bulk decrease.
Vahid reza ُSafdari; Nima Eskini; Ajang Tajdini; Vlima Bayramzadeh
Abstract
Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: ...
Read More
Wood anatomy in addition to genetic is affected by environmental factors. One of the environmental factors is soil erosion which affects anatomical properties of roots considerably. Juniperus excelsa is one of Iranin indigenous softwood and has longevity and anatomical properties of its root in two conditions: inside of soil and exposed one can reveal effects of soil erosion on wood anatomical properties of root. So many roots and barks of trees in inside of soils and exposed have been sampled and many micro-sections prepared by microtome and anatomical properties were investigated. Results showed that wood roots under soil conform of one row of late-wood and by exposing the lumen area of tracheids in early-wood and late-wood were decreased and the cells appear thicker and late-wood portion increased. The axial parenchyma inclusion of dark resins in exposed roots observed frequently. Meanwhile by exposing of roots the thickness of bark decreased and the thickness of phloem and periderm in exposed root is not as wide as normal roots.
ُSima Sepahvand; Meysam Zahedi; Samaneh vilki; Taghi Tabarsa
Abstract
Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used ...
Read More
Tannins are the most desirable natural, renewable phenolic components which obtained from plant resources. The phenolic nature of tannins causes that this materials react with formaldehyde and form tannin-formaldehyde resins. In this study, the raw materials of wheat straw and forest woods were used for producing of particleboard (with a ratio of about 50 to 50 percent) using phenol formaldehyde based on tannin. Tannin as a powder was added at 10 and 20 percent (based on dry weight of resin solution) to formalin 35% for glue making. Particleboards were made at two range of thickness, 10 and 16 mm and their properties of including bending strength, modulus of elasticity, internal bonding, thickness swelling and water absorption were measured. The results from this investigation showed that the strength properties of the made boards from combined wood chips were lower than those from pure wood chips. Also, increasing of tannin usage into phenol formaldehyde caused to increase internal bonding or adhesion, swelling and water absorption (2 and 24 hours) of the boards.
Saeid Kamrani; Ahmad reza Saraeian; Hossein Resalati; Ali Ghasemian
Abstract
The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric ...
Read More
The main objective of this study was to determine the trends of fiber dimension variation along the longitudinal direction of wheat straw as a criteria for papermaking. Zagross wheat straw was collected from the agricultural and natural resources research center, Golestan province .The fiber biometric characteristics including fiber length, fiber diameter, lumen diameter and cell wall thickness in three internodes were determined .Results showed that, the difference in fiber diameter, lumen diameter and cell wall thickness were sttistically significant between three internodes of wheat straw at 99% confident Based on the computed papermaking indices (flexibility ,softness and runkle number), it was predicted that the papers produced from the first and the third internode of wheat straw may have higher tensile,folding and burst strength and the papers produced from the second internode may have higher tear strength.
Mohammad Tasoji; Amir Nourbakhsh; Abolfazl Kargarfard; Hossein Hosseinkhani
Abstract
Physical and mechanical properties wood-plastic composites produced from wheat and rice straw particles, nano-clay, polypropylene and MAPP were investigated. The amount of polypropylene and lignocellulosic materials were selected as 60 wt% and 40 wt% respectively. The Nano-clay was added in three levels ...
Read More
Physical and mechanical properties wood-plastic composites produced from wheat and rice straw particles, nano-clay, polypropylene and MAPP were investigated. The amount of polypropylene and lignocellulosic materials were selected as 60 wt% and 40 wt% respectively. The Nano-clay was added in three levels 0, 2 and 4 wt% and the amount of coupling agent was fixed and set to 2 wt% for all treatments except for the control. The control samples were made from polypropylene and lignocellulosic materials with neither nanoclay nor coupling agent was used. The results showed that the tensile and flexural strengths were decreased by the addition of nanoparticles. For tensile and flexural modulus, adding 2 wt% of nanoclay led to an increase in both moduli. However there was a decrease in both moduli when 4 wt% nanoclay was added. The impact strength decreased adding nanoclay. There was a decrease in 24 hour water absorption when 2 wt% of nanoclay was added but an increase was observed in 4 wt% of nanoclay level. According to the mechanical and physical properties of all the treatments, the samples made of rice straw showed better results compare to wheat straw samples due to their high amount of silica and its compatibility with nanoclay. SEM test was performed.
Pulp and paper
Ahmad Jahan latibari
Abstract
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 ...
Read More
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.
Farshad Sarkhosh rahmani; Mohammad Talaeipoor
Abstract
This study was carried out with the aim of producing fluting paper from wheat straw soda–AQ pulp and OCC pulp blend. Handsheets at 120 gr/m2 basis weight were made by blending the unbleached wheat straw pulp with OCC pulp at ratios of 25, 50 and 75%. Physical and strength properties of these papers ...
Read More
This study was carried out with the aim of producing fluting paper from wheat straw soda–AQ pulp and OCC pulp blend. Handsheets at 120 gr/m2 basis weight were made by blending the unbleached wheat straw pulp with OCC pulp at ratios of 25, 50 and 75%. Physical and strength properties of these papers were measured and compared to unblended papers. Results indicated that, paper properties were considerably affected by incorporation of the wheat straw pulp. In other words, in case of utilizing wheat straw soda – AQ pulp in OCC pulp , acceptable physical and strength properties can be produced , so that , the incorporated 75% of wheat straw pulp to OCC pulp, the best thickness, air resistance, roughness, tear index, burst index, folding endurance, breaking length, CMT and RCT can be achieved. According to obtained results, unbleached wheat straw soda – AQ pulp can be used not only to enhance the physical and strength properties of fluting paper but also as a lignocellusic source for making fluting paper.
Pulp and paper
Saeed Mahdavi; masoudreza habibi; kermanian hossein
Abstract
Global concerns for preservation of forests and elimination of pollution from pulping and papermaking processes has led us to explore alternate fibrous resources other than wood and new environmentally begin pulping and bleaching processes for papermaking without sacrificing quality. Various alternate ...
Read More
Global concerns for preservation of forests and elimination of pollution from pulping and papermaking processes has led us to explore alternate fibrous resources other than wood and new environmentally begin pulping and bleaching processes for papermaking without sacrificing quality. Various alternate fibrous resources such as agricultural residues are already in use in many countries and considerable research have been undertaken to produce pulps by conventional and non-conventional processes. Wheat straw has high quantity among agricultural residues in Iran. Kraft, Soda and Ethanol-alkali pulping were carried out after sampling and preparing of wheat straw. Retention of carbohydrates is improved compared to the alkaline pulping processes, resulting in about 8 to 15 % higher yield at the same level of residual lignin. There was lower energy consumption for refining Ethanol-alkali pulps. There were no statistical differences among the physical properties. The strengths of Ethanol-alkali pulps consist of tear index, burst index and breaking length were lower than alkaline pulps, but all of the strength properties were higher than kraft and liner paper except tear index that addition of some long fiber can solve the problem.
