Pulp and paper
Iman Akbarpoor; Hossein Resalti; Ahmad reza Saraeyan
Abstract
In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, ...
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In this study, Deinking of old newspaper was investigated by chemical and enzymatic methods. Chemical treatment was done using chemicals at different times of 10, 20 and 30 minutes, consistency of 10%, temperature of 50±1!C along with washing, flotation and combination of washing/flotation. While, Enzymatic treatment was accomplished at different concentrations of 0.025, 0.05, 0.1 and 0.2% of cellulase enzyme (on the basis of oven dried waste paper), pH range of 5-5.5, different times of 10,15 and 20 minutes, consistency of 10%, temperature of 50±1!C along with washing. The results comparison of optimum chemical and enzymatic treatments showed that, deinked pulp by chemical method had higher brightness and yellowness. Also, deinked pulp by chemical method resulted the papers with higher bulk, higher caliper and higher air resistance.
Iman Akbarpoor; Hossein Resalti; Ali Solimani
Abstract
In this study, the effect of elimination and relative decrease of sodium silicate along with substituting the organic complex of sulvy-x was investigated on optical properties of CMP pulp bleached by hydrogen peroxide. The brightness of paper were increased to 66.8%, yellowness decreased to 22% and opacity ...
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In this study, the effect of elimination and relative decrease of sodium silicate along with substituting the organic complex of sulvy-x was investigated on optical properties of CMP pulp bleached by hydrogen peroxide. The brightness of paper were increased to 66.8%, yellowness decreased to 22% and opacity decreased to 80% with increase in sodium silicate charge from 0.7% to 3%. Also, with complete elimination of sodium silicate and using of sulvy-x at different levels of 0.4, 0.5, 0.7 and 1% , highest brightness and lowest yellowness were shown at 0.5% sulvy-x. These values were 66.1% and 21.8%, respectively. The brightness of paper enhanced from 61.2% to 67.3% with increasing of sulvy-x charge from 0.4% up to 0.5% blended with constant value of 0.7% sodium silicate. But the brightness decreased at higher levels. Generally, pretreatment by DTPA prepared the paper with lower brightness and higher yellowness at two different states namely silicate-free and silicate-containing with sulvy-x. Pretreatment by DTPA at silicate-free state led to decrease of opacity but at silicate-containing state terminated to improve of opacity values. Increasing of bleaching time up to 120 minutes resulted in the paper with higher brightness, higher opacity and lower yellowness at silicate containing state with sulvy-x. At silicate-free state, increasing of bleaching time up to 120 minutes led to improve of opacity while brightness improved and yellowness reduced with increase in bleaching time to 90 minutes. Also, the brightness of paper decreased at higher times (120 minutes) and yellowness increased. In conclusion, achieved results from comparison of optical properties of paper produced from peroxide bleaching of hardwood CMP pulp indicated that we could produce the paper with desirable or even better optical properties by replacing of sulvy-x rather than sodium silicate compared to conventional peroxide bleaching.
Pulp and paper
Ali Solimani; Hossein Resalati; Eiman Akbarpoor
Abstract
In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch ...
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In this research, effects of mixing the birch wood with hornbeam and beach on optical and physical properties of papers produced at constant freeness range of 300 ml, CSF and yield of 85% and reference of CMP pulp (75% hornbeam plus to 25% beach) was investigated. CMP pulp was produced from birch chips at 10,20,30 and 40% content within the conditions of pulp yield:85%, liquor to dried chip ratio (L/W) of 7/1, sulfite percent of 20% on oven-dried wood chips, cooking temperature:1600C, cooking time:85-135 minutes blended with 60-90 % hornbeam and beach. After defibration and refining the cooked wood chips, the standard hand sheets of 60 g/m2 were made from different pulps and the optical and physical properties of paper produced were compared. The results from comparing the optical properties of paper showed that using up to 40% birch chips blended with hornbeam and beach led to brightness improvement and yellowness and opacity reduction compared to control CMP pulp. Increase of birch use to 30% indicated no significant effect on opacity values at confidence level of 99% compared to control CMP pulp. Utilizing 40% birch resulted in the preparation of papers with lower caliper, smoother surface and higher air resistance.
Physics and anatomy
Meisam Aliabadi; Eiman Akbarpoor; Ahmadreza Saraeyan; Jalil Roshnasan
Abstract
This research was performed to investigate fiber biometrical properties (length, diameter and fiber thickness) of hornbeam species from Astara in Iran. Initially, disks were prepared with three trees of hornbeam species and then fiber isolation was carried out using Franklin method. Length, diameter ...
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This research was performed to investigate fiber biometrical properties (length, diameter and fiber thickness) of hornbeam species from Astara in Iran. Initially, disks were prepared with three trees of hornbeam species and then fiber isolation was carried out using Franklin method. Length, diameter and wall thickness of fiber provided were determined by laboratory microscope using eye scaled lens. The measurement of fiber dimensions was made at the pith region and at the distances of 2,6,12 and 15 centimeters and four geographical sides. The results indicated that length, diameter and wall thickness of fiber increased significantly with enhance of distance from pith. The highest fiber length, diameter and wall thickness obtained were 1.509 mm, 23.93 µm and 3.897 µm, respectively. The consequences attained from changing of fiber dimensions at various distances from pith to bark indicated that fiber dimensions change decreased by increase in distance from pith up to 15 cm and the highest change of fiber was observed at distance of 2-6 cm from pith. The results of measuring the fiber dimensions at various geographical sides didn't indicate any significant deference between the values of fiber length, diameter and wall thickness at 1% level of probability. The combined effects of distance from pith and different geographical sides also did not show any significant deference on fiber dimensions.
Iman Akbarpoor; Hossein Resalati; Ahmad reza Saraeian
Abstract
In this study, deinking of waste newspaper was investigated by conventional and enzymatic methods. Conventional deinking was done in pulping times of 10, 20 and 30 minutes along with different processes of washing, flotation and combined washing/ flotation. Enzymatic deinking was accomplished ...
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In this study, deinking of waste newspaper was investigated by conventional and enzymatic methods. Conventional deinking was done in pulping times of 10, 20 and 30 minutes along with different processes of washing, flotation and combined washing/ flotation. Enzymatic deinking was accomplished at different charges of 0.025, 0.05, 0.1 and 0.2% cellulase enzyme (based on oven-dried waste paper), pulping times of 10,15 and 20 minutes, pH range of 5-5.5 along with one-stage washing process. Optimum compositions were selected from chemical and enzymatic treatments and then physical and mechanical properties of the paper produced in optimum conditions were compared. Achieved results from comparison of the physical properties of optimum chemical and enzymatic treatments showed that, the paper produced from deinked pulp by conventional method had higher calliper, bulk and porosity. Using of 0.1% cellulase resulted the papers with higher tensile and breaking length compared to chemical treatments. The papers could be produced with similar burst and tear indexes compared to chemical treatments using of 0.1% cellulose, as well.
Meisam Aliabadi; Eiman Akbaepoor; Ahmad reza Saraeian
Abstract
In this study, the effect of organic complex "sulvy-x" on the optical properties of hornbeam CMP pulp bleached with hydrogen peroxide was investigated. Sulvy-x was used in two sequences silicate-free and silicate containing in hydrogen peroxide bleaching. The brightness of papers increased to 60.52 and ...
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In this study, the effect of organic complex "sulvy-x" on the optical properties of hornbeam CMP pulp bleached with hydrogen peroxide was investigated. Sulvy-x was used in two sequences silicate-free and silicate containing in hydrogen peroxide bleaching. The brightness of papers increased to 60.52 and the yellowness decreased to 22.6 with increasing silicate charges up to 1% . However, at higher levels than 1% , the brightness decreased and the yellowness increased. Without dosage of sodium silicate but using 0.5% of sulvy-x, maximum brightness of 59.3% and minimum yellowness of 23.4 % ISO was achieved. In silicate-containing bleaching, combination of 0.5% sulvy-x and 0.7% sodium silicate resulted the highest brightness (60.28 % ISO) and the lowest yellowness (23 % ISO). Optimum charge of sodium hydroxide and hydrogen peroxide were determined as 2.5% and 5%.The best time for bleaching of hornbeam CMP pulp was 90 minutes in either sequences. With regard to results obtained, utilization of the organic complex of sulvy-x could be a suitable substitution for sodium silicate which produces the pulp with higher brightness and lower yellowness in conventional peroxide bleaching.
Pulp and paper
Saeid Kamrani; Ahmad reza Saraeyan; Eyman Akbarpoor
Abstract
In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length ...
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In this study, mechanical and optical properties of CMP, one stage APMP and two stage APMP pulps ( from Tajan wheat straw Golestan province ) were investigated. wheat straw collected at research center of Agriculture and Natural resources of Golestan province. Fiber dimensions such as average fiber length , diameter cell , lumen and fiber wall thickness were assessed at 1.18mm, 18.156, 11.461 and 3.396 microns, respectively. chemical components such as cellulose , lignin , ash and extractives were assessed at 53.7, 21.1, 5.1 and 8.5 percent, respectively. Based on the preliminary experiment results, impregnation temperature was 950C, impregnation times of 10, 20, 30, 40 minutes, caustic charge 10% and peroxide charge was 3% in CMP ,one stage APMP and two stages APMP pulps. Considering pulp properties and treatment conditions, many treatments including 20 and 40 minutes treatments were selected for making of handsheet. The selected pulps were refined up to 350 ml (CSF) freeness prior to making of hasndsheet. Final results indicated that two stages APMP pulp (impregnation in time 40 minutes) had the highest burst strength, breaking length and brightness. Also, the results of yield and tear strength showed that, there was no meaningful difference at the 5% level between three methods CMP, one and two stages of APMP pulps.
