Pulp and paper
Ghasem Asadpour; Hadi Boroshkian; Hossein Resalaty
Abstract
The purpose of this study is to investigate the effect of pH on cellulase enzyme activity on the drainage and strength properties of OCC pulp. Recycled OCC pulp was pretreated with consistency 0.4 percent, in constant condition the temperature is 50˚C, duration 1 hour and range pH:4-4.5, 8-8.5 with ...
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The purpose of this study is to investigate the effect of pH on cellulase enzyme activity on the drainage and strength properties of OCC pulp. Recycled OCC pulp was pretreated with consistency 0.4 percent, in constant condition the temperature is 50˚C, duration 1 hour and range pH:4-4.5, 8-8.5 with cellulase enzyme at three levels 0.1, 0.3 and 0.5 percent (according to paper pulp dry weight). The results showed that pretreatment of cellulase enhances the freeness of pulp in comparison with the control samples, but by increasing the concentration of enzyme, the freeness of pulp was reduced in pH:4-4.5 the highest freeness is at the level of 0.1 percent and in pH:8-8.5 at the level of 0.3 percent. Also, papers were evaluated for resistance properties. The results showed that the increase in the use of cellulase enzyme has increased the tensile and burst strength index. As, in the alkaline pH, the effect of the cellulase enzyme on the increase of these strength was higher than the acid pH. The OCC pulp strength tear index, only in low levels of cellulase enzyme and in acidic pH, increased strength was observed, but with increasing enzyme consumption, there was a decrease in tear strength. Also, for strength to crushing, there was no specific trend regarding the amount of enzyme and pH on enzyme function.
Pulp and paper
Lila Karami motaghi; Hossein Hosseinkhani; Fardad Golbabaei
Abstract
In this study pulp and hand sheets paper characteristics of Salix nigra wood kraft and soda pulp and paper were investigated. Average density of dry and bulk density wood were determined 0.35 and 150 kg/m3 and average fiber dimension consist of fiber length, fiber diameter were measured, 1100 and 30 ...
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In this study pulp and hand sheets paper characteristics of Salix nigra wood kraft and soda pulp and paper were investigated. Average density of dry and bulk density wood were determined 0.35 and 150 kg/m3 and average fiber dimension consist of fiber length, fiber diameter were measured, 1100 and 30 µm, respectively. The chemical composition were determined as cellulose 42%, lignin 28% and extractive 4%. In order to coocking and pulping, Kraft (Sulfate) and soda process were used. For comparison of fiber dimensions, physical properties and chemical composition of the mean and standard deviation, yields of pulp in the form of a factorial randomized complete block design test, the strength properties of handsheets table ANOVA and for group means of the Duncan were used. All paper strengths of two hour cooking show better results than one hour cooking times, and all paper strengths of 22% alkaline show better result than 18%, also all paper strengths of 100% mixture show better result than 25% mixture (100% mixture only contain kraft pulpof salix nigra). The results of hand sheet strength indicated that Kraft pulp of salix nigra wood will provide a suitable to mix with short fiber hard wood pulp.
kezhal Moradyan Gilan; Mohammad Azad fallah; Amir abbas Shayghani akmal; Ali Abdolkhani
Abstract
This research was carried out with the aim of determining dielectric properties of bagasse unbleached soda pulp, long fiber kraft pulp and a mixture of both (20% kraft + 80% bagasse soda).The hand-sheets with 60 g/m2 basis weight were made after adjusting the freeness of pulps at levels of 200 ± ...
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This research was carried out with the aim of determining dielectric properties of bagasse unbleached soda pulp, long fiber kraft pulp and a mixture of both (20% kraft + 80% bagasse soda).The hand-sheets with 60 g/m2 basis weight were made after adjusting the freeness of pulps at levels of 200 ± 25 ml and 400± 25 ml and dried under mild condition around zero moisture content. Then the impregnation processes were carried out with mineral oil under vacuum at certain temperature. Finally the dielectric properties of impregnated papers including capacitance, insulation resistance, dielectric constant, and loss tangent were measured. The results showed that the refining give rise to enhance the dielectric properties in particular capacitance value. The dielectric properties of oil impregnated paper also increased. According to the preliminary results, unbleached soda bagasse pulp and its mixture with kraft pulp (20% Kraft -80% bagasse soda) found to be the suitable alternative with respect of dielectric applications for replacing kraft pulp, providing successful performance of the aging test.
Pulp and paper
Ahmad Samariha; Jafar Ebrahimpoor kasmani; Saeed Mahdavi
Abstract
Rapeseed straw was collected from a cultivation farm in the vicinity of Babul, Mazandaran. Average fiber length, width, lumen diameter and cell wall thickness were measured as 860, 27.95, 18.86, and 4.42 µm respectively. Chemical components of rapeseed straw including cellulose, lignin, ash and ...
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Rapeseed straw was collected from a cultivation farm in the vicinity of Babul, Mazandaran. Average fiber length, width, lumen diameter and cell wall thickness were measured as 860, 27.95, 18.86, and 4.42 µm respectively. Chemical components of rapeseed straw including cellulose, lignin, ash and extractives were measured as 44%, 19.21%, 6%, and 13% respectively. Optimum pulping conditions to reach the pulp yield of 66%, were selected applying chemical charge of 20% (based on Na2O), cooking temperature of 170 ºC, and cooking time of 30 min. The pulps were refined to 350 and 400 ml CSF using PFI mill. Statistical analysis showed that mechanical properties of hand sheets with the basis weight of 127 g m-2 made from rapeseed straw NSSC pulp at the freeness of 350 and 400 ml CSF exhibited better properties compared to mixed hardwood NSSC pulp to produce fluting paper.
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 ...
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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.
Pulp and paper
Behzad Kord
Abstract
This study is for identifying of the effect of refining intensity on pulp and paper properties made from eucalyptuswood. For this purpose three normal eucalyptus camaldulensis spp trees were randomly cut down from Shastkolateh Experimental Forest located in Gorgan. From each tree, one disk ...
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This study is for identifying of the effect of refining intensity on pulp and paper properties made from eucalyptuswood. For this purpose three normal eucalyptus camaldulensis spp trees were randomly cut down from Shastkolateh Experimental Forest located in Gorgan. From each tree, one disk with 50cm thickness from breast height were selected for pulp making. Then disks converted to chips by chipper, and the chips were cooked by kraft process, the cooking conditions were as following effective alkali 20%, sulfidity 25%, tempreture 190 0C and Time 90min. After cooking and pulping process, the pulp refined with PFI Mill in 5 different intensity with 0 rpm, 500 rpm, 1500 rpm, 2500 rpm and 3500 revelutions. Then, papermaking and measuring the paper properties such as freeness, tensile strength, tear strength, burst strength and density were done. Then data were statisticaly analysed. The results indicated that, there are significant difference between pulp and paper properties made of eucalyptus camaldulensis spp wood with 5 different refining intensity in 95% confident level. As increasing of refining intensity and refining revolutions, freeness and tear strength of paper decreased but tensile strength, burst strength and density of paper incrased. However, the highest value of freeness and tear strength of paper related to refining intensity with 0rpm revelution (without refining) and highest value of tensile strength, burst strength and density of paper related to refining intensity with 3500rpm revelution