Pulp and paper
Omid Hosseinzadeh; Ahmad Jahan latibari
Abstract
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 ...
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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.
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.
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.
Physics and anatomy
Abdolrahman Hosseinzadeh; Ahmad Jahan latibari; Hossein Familian; Saeed Mahdavi; Sayed javad Sepidehdam
Abstract
In this investigation, samples were collected from three tamarix species including: Tamarix meyeri from northern part and T. aphylla and T. strica from the southern parts of Iran. Nine dominat tamarix trees were felled, three for each species. From each tree 10 cm thick cross-sections at three different ...
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In this investigation, samples were collected from three tamarix species including: Tamarix meyeri from northern part and T. aphylla and T. strica from the southern parts of Iran. Nine dominat tamarix trees were felled, three for each species. From each tree 10 cm thick cross-sections at three different heights (5, 25 and 50% of the tree height) were cut. These disks were used for anatomical study, and remaining logs were transferred to laboratory for physical and chemical tests. The results of this study revealed that wood from these three species of tamarix is considered unsuitable for pulping and in the case, It is used for pulping, the pulp yield will be low and the strength of the pulp will be quite low, which is the consequence of short and thick-walled fibers that will not provide adequate fiber bonding. In addition, because of the large diameter and thick-walled fibers, the strength properties of the woods are also low.
