Pulp and paper
Hosein Valayi; Ahmad Jahan Latibari
Abstract
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 ...
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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.
Mahid Farzi; Ali akbar Enayati; Davood Parsa paghoh
Abstract
In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the ...
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In this investigation, soda pulps from old rags applying three pulping times (60, 120 and 180 minutes ) and three levels of active alkali ( 6,8, and 10% NaOH based on OD weight of rag) and pulping temperature of 125º C were produced. Liquor to rag ratio was kept constant at 11:1(based on the weight of the rag). After pulping, hand sheets were made and then both strength and optical properties of hand sheets were measured. It was revealed that, the optimum condition for rag pulping was; 8% active alkali and 120 minutes. At this pulping conditions, the pulping yield and mechanical and optical properties of pulp were measured as yield; 86.46 %, tear index; 20.12 mN.m2/g, burst index; 2.09 kPa.m2/g, breaking length; 1.96 km, brightness; 95.86 % and opacity: 96.39
Pulp and paper
Said mohammad Mazhari mosavi; Saeed Mahdavi; Syed zyaldin Hosseini; Hossein Resalti; Hossein Usefi
Abstract
This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. ...
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This research is aimed to study the possibility of rapeseed straw (Hayolla401) pulping and its paper characteristics, using Soda-AQ process. The average fiber length was found 1.04 millimeter and the average fiber diameter, lumen and thickness were found 28.00, 19.09, and 4.91 micrometer, respectively. Cellulose, lignin, extractive material (acetone solved) and ash were measured 41.66, 16.00, 1.63, and3.46 percent, respectively. Cooking condition was determined as follow: Soda as 16, 18, and 20 percent on the basis of rapeseed dry straw, temperature was set at 175 and 185 Cº, cooking time was set at 40 and 70 minutes, and straw to liquid ratio was set at 1/8. The amount of anthraquinone added to cooking liquor was 0.2%, based on rapeseed dry straw. Using severe cooking factors caused reduction of yield and Kappa number in both methods. Refining was performed on selected pulps in order to reach 35025 (ml,CSF) freeness. The 60 gr/m² hand sheets were made in order to determine mechanical strength and physical properties. Average thickness, density and bulk is measured at 86.4µ, 0.69gr/cm³ and 1.44cm³/gr respectively. Average tear index, burst index, breaking length and tensile indexare measured at 4.6 mN.m²/gr, 3.5 kpa.m²/gr, 7.4km and 72.6Nm/g respectively.
The results showed that however screen yield of rapeseed straw pulp is low but kappa number and mechanical properties of pulp is suitable,compared with the other agriculture residues, so Rapeseed pulp can be used in paper making industries.
Physics and Mechanical Wood
Shamohammad Amiri
Abstract
Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl ...
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Anatomical, chemical and pulping characteristics of Cotton stalk as a nonwood material.Fiber length, fiber diameter, lemun and cell wall thickness were measured at 24.47, 16.43 and 4.02 mn respectively. Paper making coefficients were also calculated coefficient, flexibility coefficient and ranckl coefficient were calculated at 34.28, 67.14 and 48.93 respectively.Chemical composition of cotton stalk was determined at 47.83%cellulose, 21.66% lignin, 2.13% alcohol-acetone extractives and 2.83% ash.Soda pulping at following variables was investigated. Three levels, of cooking temperature (140, 160 and 180 degree Celsius), three cooking time (30, 40 and 50 minutes) and raw material condition (normal and debarked stalks). Active alkali of 20% (based on NaOH) and liquor to wood ratio of 5: 1 were kept constant for all soda cooks. The optimum combination of variables160 degree Celsius I temperature, 40 minutes time and debarked raw material. The yield and kappa no. of pulp obtained at this cooking condition was 50.4% and 89.15 respectively.
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 ...
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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.
Saeed Mahdavi; masoudreza habibi; Kamyar Salehi; Hossein Familian; kermanian hossein
Abstract
The common reed, P.australis, covers vast region in south of Iran. Specially, there is possibility of executing harvest in Hoor-Alazim canebrake as a reed natural provenance. It has good properties for papermaking in comparison of typical nonwood materials. Chips were pulped using typical kraft, soda ...
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The common reed, P.australis, covers vast region in south of Iran. Specially, there is possibility of executing harvest in Hoor-Alazim canebrake as a reed natural provenance. It has good properties for papermaking in comparison of typical nonwood materials. Chips were pulped using typical kraft, soda and NSSC processes. Standard testing of pulp properties was made using TAPPI procedures. Pulps were beaten in a PFI mill to 400m.l.csf freeness level. Handsheets were made from the refined reed pulps for measuring strengths. Screen yield and kappa number of soda pulp were about similar to kraft pulp. NSSC pulp has lower kappa number than the soda at the equivalent screen yield. Energy consumption for beating from kraft, soda and NSSC pulps reduced respectively. Initial freeness of reed pulp was near to hardwood typical, thus good drainage and runnability on reed papermaking is expectable. The physical properties of reed handsheets were higher than newsprint and fluting pulps of Mazandaran Company. Overall, soda and NSSC reed pulps can be used in producing of newsprint and fluting papers based on the properties.
