Pulp and paper
Mohaddeseh Ramezanpour-Charvadeh; Hamid reza Rodi; Hossein Jalali-Torshizi; Hamidreza Ghomi marzdashti
Abstract
DOR:98.1000/1735-0913.1398.34.76.66.1.9.1578 A need for control of pathogenic microorganisms in contaminated environments has motivated to prepare the products including antibacterial papers resisting against growth of such creatures. Different methods and materials have been used to make these papers. ...
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DOR:98.1000/1735-0913.1398.34.76.66.1.9.1578 A need for control of pathogenic microorganisms in contaminated environments has motivated to prepare the products including antibacterial papers resisting against growth of such creatures. Different methods and materials have been used to make these papers. The purpose of current research is to fabricate silver nanoparticle by means of plasma method and investigate the effect of adding it to the Kraft pulp on the properties of resulting papers. To do this, silver nanoparticles have been fabricated in optimized conditions of 1 kHz frequency, 2 A current and 4 kV voltage, using an instrument developed in Laser and Plasma Research Institute, Shahid Beheshti University. The DLS test confirmed the average size of silver particles at nano scale ( 41.2 nm). Then, the prepared silver nanoparticles were added by levels of 0, 25, 50 and 75 ppm to the Kraft pulp accompanying by cationic polyacrylamide (CPAM) as a retention aid to about 0.05 based on oven dry of fibers. The results of paper properties evaluation (having basis weight 60±3 g/m2) have shown that addition of silver nanoparticles synthesized by plasma method lead to loss of paper strength characteristics. The paper brightness has also exhibited a meaningful decrease. However, the paper opacity and antibacterial property develop significantly in the consumption levels higher than 50 ppm.
Ramin Veysi
Abstract
In this research, chips of kiwi residues from western Mazandaran (Tonkabon region) were randomly chosen and its kraft pulp was prepared with yield of 53% for 105 minutes. The kraft liner handsheets were prepared from both kiwi and Chooka Mill kraft pulps (control sample), first in a separate and second, ...
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In this research, chips of kiwi residues from western Mazandaran (Tonkabon region) were randomly chosen and its kraft pulp was prepared with yield of 53% for 105 minutes. The kraft liner handsheets were prepared from both kiwi and Chooka Mill kraft pulps (control sample), first in a separate and second, in mixed way. Then, their optical and mechanical properties were compared according to TAPPI standard test methods. Results showed that the highest tear strength and cobb 60 and the lowest breaking length, burst and CMT values were in the handsheets obtained from pure kiwi kraft pulp. The handsheets’ properties increased in the samples prepared from mixed pulps. In general, the highest values of breaking length, burst strength, tear strength, cobb 60, brightness and RCT were observed in the handsheets prepared from mixed 10-30% kiwi kraft pulp and mill kraft pulp. The results also pointed out that the above mentioned strengths could be improved by adding 10-30% of kiwi kraft pulp to 30-70% mill kraft pulp replaces part of mill kraft pulp, but it is not possible for pure kiwi kraft pulp.
Pulp and paper
Noraldin Nazarnezhad; Naser Rasol pour hedayati; Omid Ramazani
Abstract
Chitosan is known as a natural polymer which improves strengths of papers. So, in this study investigated improvement of chitosan absorption on modified craft fibers and increase its efficiency. The effects of chitosan were experimented in three levels of 0%, 0.75% and 1.25% on modified kraft fibers ...
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Chitosan is known as a natural polymer which improves strengths of papers. So, in this study investigated improvement of chitosan absorption on modified craft fibers and increase its efficiency. The effects of chitosan were experimented in three levels of 0%, 0.75% and 1.25% on modified kraft fibers surfaces with 3% hydrogen peroxide in different pH levels (5.5, 7 and 8.5). The results showed that chitosan had better performance at low dosages and alkaline conditions. Also surface fibers modification by hydrogen peroxide caused increase of carboxyl groups and fibers anionic charge. Fibers anionic charge with participant of chitosan formed a dual system. The apparent density increased from acidic pH to alkaline. As, the highest apparent density were reached in alkaline pH and 0.75 % of chitosan. Also, tensile index and burst index of paper were reached in alkaline pH and 0.75 % of chitosan. Whereas, chitosan and the surface modified fibers of kraft pulp did not have a significant level on the tear index
Zinat Farhadi; Ahmad reza Saraeian; Mohammad reza Dehghani firuzabadi
Abstract
This study was done to investigate the effect of bark content on the physical and mechanical properties of kraft pulp from chips Ppopulous deltoids. Three tree of the populous deltoids from the same age were randomly selected cut from Shastkalate research forest Gorgan. A disc was taken from each tree. ...
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This study was done to investigate the effect of bark content on the physical and mechanical properties of kraft pulp from chips Ppopulous deltoids. Three tree of the populous deltoids from the same age were randomly selected cut from Shastkalate research forest Gorgan. A disc was taken from each tree. The discs were completely debarked and wet weight of wood and bark from each disc was determined. Then weight ratio of wood/bark was determined in each disc. Kraft pulp was prepared under following pulping condition: sulfidity 25%, AA: 20%, temp: 170 0c, l/w: 6/1 and bark content as 0 , 6, 12, 18 and 24%, by weight. Pulp with kappa number around 20 was prepared from each treatment, which were separately beaten to reach freeness value around 350 ml,CSF. To determined the effect bark content on yield and kappa number of the pulp and their physical and mechanical properties, F test was used in completely randomized, and for comparison of the means, Dunkan test was used. Yield and kappa number of the pulps were as 50/32 - 52/03% and 20/37 - 21/17, respectively. With increasing, of the bark content, density of paper was decreased and the lowest value of which was 0/477 g/cm2for bark – contained pulp. Also, with increasing of the bark content to 18%, strength properties of the related pulp was improved.
Pulp and paper
Hossein Resalti; Morteza Abdolah bik marandi; Ahmad reza Saraeyan
Abstract
The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric ...
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The effect of using commercial xylanase enzyme in prebleaching of bagasse kraft pulp was investigated. Xylanase enzyme from Trichoderma viride was added to pulp at various doses of 10, 25 and 50 IU/g pulp for reaction time 2h and then the enzyme treated pulp was bleached in ADED sequences (Acid sulfuric +Dioxide chlorine 4, 6, 8, 10% + Alkaline extraction + Dioxide chlorine 2% as available chlorine). The results have shown that with increased dioxide chlorine in D1 bleaching sequence, final brightness of bleached pulp was increased significantly (P<0.01). Furthermore, in the case of treated samples by xylanase enzyme optical properties of bleached pulp such as brightness and opacity were increased significantly (P<0.01). For yellowness, revolution of refiner for distinct pulp freeness and kappa number have shown decreased significantly (P<0.01). Maximum of brightness and minimum of kappa number and yellowness were belong to 25 IU/g pulp treatment that about 10.8, 3.98% and 2.24 unit have difference significantly (P<0.01) as compared with control sample respectively. Maximum of opacity and Minimum was belong to 50IU/g pulp treatment that about 3 and 13.24% have difference significantly as compared with control sample respectively. Regardless of obtained results 25IU/g pulp treatment could be selected as optimal treatment.
