Farahnaz Behzadi; Sead Javad Sepidehdam; Ahmad Jahan Latibari; Alireza Khakifirooz
Abstract
The objective of this research was to investigate the combined effect of polyaminoamide-epichlorohydrin (PAE) and carboxymethyl cellulose (CMC) on the mechanical properties of tissue paper made from virgin pulp. Three levels of CMC (0%, 0.5%, 1%, and 1.5%), and three levels of PAE (0%, 0.5%, and ...
Read More
The objective of this research was to investigate the combined effect of polyaminoamide-epichlorohydrin (PAE) and carboxymethyl cellulose (CMC) on the mechanical properties of tissue paper made from virgin pulp. Three levels of CMC (0%, 0.5%, 1%, and 1.5%), and three levels of PAE (0%, 0.5%, and 1%) based on the dry weight of the fibers were used. A mixture of 60% short fiber and 40% long fiber pulps was formed by mixing bleached softwood and bleached hardwood pulps provided by Latif tissue making plant and the chemicals were added. Then 80 g/m2 laboratory hand sheets were prepared. All samples were placed in oven at 100±5 °C and also conditioned (23±1°C and 50±2% relative humidity) for 24 hours prior to testing. Strength properties (wet and dry tensile, wet and dry burst) of the hand sheets were measured. Results indicated that treating of pulps with both CMC and PAE as additives leads to enhancement of the mechanical properties of the paper sheets and higher dosages of CMC and PAE, improved all strength properties
Ahmad Jahan - Latibari; Fardad Golbabaei; Abas Tamjidi; Babak Sobhani; Komail Raofkia
Abstract
Based on the need and the importance of urban wood residues to fulfill part of the wood raw material for particleboard production, and to increase its value as raw material, the potential of such material including wood residues from pine and sycamore trees as well as grape fruit tree pruning for the ...
Read More
Based on the need and the importance of urban wood residues to fulfill part of the wood raw material for particleboard production, and to increase its value as raw material, the potential of such material including wood residues from pine and sycamore trees as well as grape fruit tree pruning for the production of particleboard was investigated. The results are compared with similar particleboard produced using particles from mixed hardwoods generated at the industrial scale mill. Laboratory boards at the density of 650 kg/m3 were made changing the resin dosage at three levels of 10, 11 and 12% based on the oven dry weight of the particles and the strength and thickness swelling of the boards were measured as defined in relevant EN standards. Due to the lower bulk density of particles from pine wood, boards produced using the particles generated the highest MOR and MOE, and the lowest MOR and MOE were measured on boards produced using particles from mixed hardwoods. However, the IB of the boards on mixed hardwoods and application of 12% resin was superior (1.18 MPa.) and the lowest 1B (0.36 MPa.) was measured on the boards produced using the mixture of 50% pine and 50% sycamore particles. The thickness swelling of the sycamore boards were inferior and the lowest thickness swelling was measured on the pine particleboards.
Pulp and paper
Mohammad ali Azad far; Rabie Behroz; Ahmad Jahan - Latibari
Abstract
The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum ...
Read More
The influence of oxygen delignification as an environmental friendly process, was investigated on Soda/AQ pulp from Old Corrugated Container (OCC) fibers. Oxygen delignification at four levels of alkali (2, 3, 4 and 6% based on OD weight of pulp) has been applied and the optimum alkalinity to reach optimum Kappa no, yield and brightness, opacity and strength based on 60 g/m2 hand sheets were determined. The results indicated that application of oxygen delignification marginally reduced the opacity of the pulp. Tear strength increased where as tensile and burst strength decreased. Based on the comparison of the data from oxygen delignified pulp, it is concluded that oxygen can be utilized to improve the properties of soda-AQ pulp from OCC prepared for bleaching step. Carbohydrates are preserved while removing lignin. Normalized equations revealed that oxygen delignification at 3% alkali produced the best results.
Pulp and paper
Reza Hosseinpoor; Ahmad Jahan - Latibari; Ajang Tajdini; Sayed javad Sapideh dam; Ramin Farnod
Abstract
The impact of chemical treatment variables including treatment time and temperature, chemical charge as well as pulp freeness on fiber quality of Colza stem chemi-mechanical pulp was studied using Fiber Quality Analyzer (FQA). Three treatment times (15, 30 and 45 minutes), two treatment temperatures ...
Read More
The impact of chemical treatment variables including treatment time and temperature, chemical charge as well as pulp freeness on fiber quality of Colza stem chemi-mechanical pulp was studied using Fiber Quality Analyzer (FQA). Three treatment times (15, 30 and 45 minutes), two treatment temperatures (125 and 145 °C), two chemical charges (4% NaOH + 8% Na2SO3 and 8% NaOH +12% Na2SO3) as well as pulp refining were evaluated. The results revealed that at higher values of treatment variables, fiber average length was reduced and varied between 0.49 and 0.65 mm. However, the influence of pulp refining on fiber average length was not very pronounced. Pulps contained between 55 -63 % fines, which is on the high range and refining increased the fine content by 5%. Fiber coarseness varied between 10 and 41 mg/100m which was raised to 14 and 53 mg/100m upon refining. Even though refining did not alter fiber curl, but fiber kinks were increased.
Physics and anatomy
Ahmad Jahan - Latibari; Fardad Golbabaei; Amir Zyadzadeh; Majid Farzi; Arad Vaziryan
Abstract
Fiber length, diameter and lumen diameter and its distribution is determined. Five stalks were randomly selected and after cleaning, the internodes and nodes of each stalk were separated. Each part was depithed manually and then experimental samples were cut from these depithed parts. ...
Read More
Fiber length, diameter and lumen diameter and its distribution is determined. Five stalks were randomly selected and after cleaning, the internodes and nodes of each stalk were separated. Each part was depithed manually and then experimental samples were cut from these depithed parts. Each sample was defibered according to procedure developed by Franklin, 1954. After defibration, fiber length, diameter and lumen diameter of 30 fibers were measured. Each stalk contained 10 nodes and internodes.
Average fiber length of internodes and nodes were determined at 1.004 and 0.802 millimeter respectively. The difference in averages of fiber length for different stalks, different heights in each stalk and between nodes and internodes were significant at 99% level. Fiber length distribution curves for internodes, nodes and all fibers show uniform and symmetrical distribution and the highest points in distribution curves are all at similar fiber length.
Average fiber diameter for internodes and nodes were determined at 16.8 and 20.1 µm respectively which are significantly different at 99% level. Fiber diameter distribution curves for nodes, internodes and all fibers also shows uniform and symmetrical shape, but the highest point for internodes is located at lower fiber diameter than nodes. The average lumen diameter for internodes and nodes were measured at 9.42 and 12.7 respectively which is significantly different at 99% level. The distribution curves for lumen diameter is identical to fiber diameter.
The results indicate that the fiber geometry of cornstalks is similar to hardwoods and other agricultural residues and it can be utilized for production of lower grade pulps such as fluting paper pulp.
