Pulp and paper
soleiman zaheri; Ali Ghasemian; Mohammadreza Dehghani Firouzabadi; Ghasem Asadpur
Abstract
AbstractBackground and Objective:Cellulose-based paper is an important renewable resource composed of cellulose, hemicellulose, and lignin. Due to its advantages such as lightweight, flexibility, low cost, and environmental friendliness, it is widely used. However, cellulose-based paper is inherently ...
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AbstractBackground and Objective:Cellulose-based paper is an important renewable resource composed of cellulose, hemicellulose, and lignin. Due to its advantages such as lightweight, flexibility, low cost, and environmental friendliness, it is widely used. However, cellulose-based paper is inherently flammable. As a result, modifying paper with organic flame retardants is of great significance to reduce fire hazards and expand the application range of cellulose-based paper. This study investigates the effect of diammonium phosphate and nanoclay, in combination with cationic starch, on the properties of paper produced from bagasse soda pulp.Materials and Methods:For this purpose, paper was obtained from bagasse soda pulp at Pars Paper Factory, with a basis weight of 120 g/m² and an average thickness of 0.185 mm. The paper was then coated with different concentrations of diammonium phosphate and nanoclay (10, 20, and 30%) along with 10% cationic starch. The coating process was carried out using an Auto Bar Coater, and the samples were dried in an oven at 60–65°C for 10 minutes. After drying, the samples were kept at room temperature for 2 days. Various tests were conducted on the samples, including liquid penetration resistance (Cobb test), thickness, contact angle, tensile strength, burst resistance, and tear resistance. Additionally, the fire-related properties of the paper, including thermal stability, burning behavior, and vertical flammability, were evaluated.Results:Coating paper with diammonium phosphate (DAP) and montmorillonite nanoclay in the presence of cationic starch improved the paper's hydrophobic properties and flame resistance. However, overall, the DAP-coated papers demonstrated better performance compared to those coated with nanoclay. This superiority is due to the formation of uniform layers and the blockage of surface pores, which prevents water penetration and increases hydrophobicity compared to nanoclay-coated and control samples. The use of DAP at an optimal concentration of 20% increased tensile strength but led to a reduction in tear and burst strength. At higher concentrations, this coating played a more effective role in enhancing the mechanical properties of the paper.Increasing the concentration of diammonium phosphate to 30% significantly increased the char yield, indicating improved thermal resistance of the paper. Both coating materials reduced the thermal decomposition temperature and increased the char yield, acting as barriers to prevent further combustion. In vertical flammability tests, DAP-coated papers at higher concentrations exhibited shorter ignition times and lower char lengths, displaying self-extinguishing behavior.The results of Fourier-transform infrared spectroscopy (FTIR) confirmed the flame-retardant performance in the condensed phase. Furthermore, the thermogravimetric analysis (TGA) of the samples showed that the treated samples had the highest char residue percentage compared to the control sample. The flame propagation pattern analysis also indicated improved fire resistance properties in the treated samples compared to the untreated ones. Additionally, all strength properties (such as tensile strength, burst strength, and tear strength) improved in the treated samples.Overall, this study demonstrated that coating with diammonium phosphate and nanoclay in the presence of cationic starch significantly improves the physical and flame resistance properties of bagasse paper. Notably, using DAP at a 30% concentration increased the char yield to 48.165%, equivalent to a 133% increase compared to the control sample and a 111% increase compared to nanoclay. These findings confirm that modifying paper made from bagasse soda pulp with this combination enables the production of paper with high flame-retardant properties, favorable char yield, and no emission of harmful substances such as halogens or formaldehyde.Conclusion:Overall, the use of diammonium phosphate and nanoclay in the presence of cationic starch as coating materials can improve the physical and mechanical properties of bagasse-based paper and make it more suitable for flame-resistant applications. Thus, these treated paper sheets can be used as fire-resistant paper-based materials.
Pulp and paper
Jafar Ebrahimpour Kasmani; Ahmad Samariha
Abstract
Background and objectives: Fruit packaging cardboard protects fruits from impacts, pressure, and damage during transportation, while helping to maintain their freshness and quality. To achieve these objectives, it is essential to enhance the strength of the cardboard and minimize the interaction between ...
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Background and objectives: Fruit packaging cardboard protects fruits from impacts, pressure, and damage during transportation, while helping to maintain their freshness and quality. To achieve these objectives, it is essential to enhance the strength of the cardboard and minimize the interaction between its interior and exterior. At the same time, it must be biodegradable, durable, and environmentally friendly. Kraft paper is recognized as a suitable option for preserving the quality of fruits. Therefore, this research aims to improve the barrier and mechanical properties of cardboard by applying coatings of nano-graphene, fluorine, and zein, both separately and in combination, to provide consumers with higher quality cardboard.
Methodology: The brown kraft liner paper with a basis weight of 120 grams was obtained from the Mazandaran Wood and Paper Company. The nanographene type AO-4 was sourced from Graphene Supermarket in the USA, zein protein from Sigma Aldrich, and fluorine from Mine Kavaran Production Group. For coating, the nanographene, zein, and fluorine were weighed in specified weight percentages and mixed with 100 grams of distilled water for 30 minutes at 50 degrees Celsius, depending on the treatment conditions. Then, 2.5 grams of styrene-butadiene latex and 0.5 grams of dispersant D200 were added to the mixture and homogenized for 20 minutes at 1500 RPM. A 5% cationic starch solution was also added as a retention aid to enhance the coating. The coating solutions were applied to the paper sheets using an Auto Bar Coater (GBC - A4 GIST Co., Ltd). The physical and mechanical properties were measured according to TAPPI and ISO standards. The experimental design was completely randomized, and data analysis was performed using one-way ANOVA and Duncan's test at a 95% confidence level.
Results: The one-way ANOVA analysis indicated that there are significant differences at the 5% level among the thickness swelling, water absorption, and porosity of the 8 types of paper. The greatest thickness swelling was observed in the brown liner paper coated with graphene and fluorine, while the lowest thickness swelling was found in the control sample, with a difference of 27% between the maximum and minimum thickness swelling. The lowest water absorption was noted in the brown liner board paper coated with zein, fluorine, and nano-graphene, with a difference of 647.5% between the maximum and minimum water absorption. Additionally, the least porosity was attributed to the paper coated with nano-graphene, showing a difference of 7365.8% between the maximum and minimum porosity. Density analysis revealed that the highest density was observed in the sample coated with zein and nano-graphene, with a difference of 14.5% between the maximum and minimum density. Furthermore, the highest surface smoothness was recorded in the paper coated with nano-graphene and zein, with a difference of 23.9% between the maximum and minimum surface smoothness. For the tensile and tear resistance index, no significant difference was observed at the 5% level, with differences of 15.5% and 26.4% between the maximum and minimum tensile and tear resistance indices, respectively. However, for burst resistance, the lowest value was found in the paper coated with fluorine and zein, with a difference of 14.2% between the maximum and minimum burst resistance. In terms of ring crush test, the highest resistance was related to the paper coated with zein, fluorine, and nano-graphene, with a difference of 16.1% between the maximum and minimum ring crush test.
Conclusion: The goal of food packaging is to extend shelf life and protect against spoilage factors. Paper and cardboard, as packaging materials, have specific advantages and disadvantages, including a lack of resistance to moisture. This research addresses the improvement of the physical and mechanical properties of kraft liner paper for fruit packaging and has demonstrated that coating increases thickness swelling and reduces water absorption. These coatings enhance the prevention of water absorption by penetrating the pores of the paper. Various factors affect water permeability, including the paper structure and the type of coating. The use of nano-graphene and zein leads to a reduction in paper porosity and an improvement in its mechanical properties. In this study, coating the paper with nano-graphene and zein significantly increased barrier properties and improved paper quality. Additionally, the results indicate that these compounds can help reduce water absorption and porosity of the paper.
Nano composite
Shaghaiegh Rezanezhad; Noureddin Nazarnezhad; Hosein Resalati; Seyed Majid Zabihzadeh
Abstract
Background and objectives: Carboxy methyl cellulose (CMC) is one the ether derivatives of cellulose and is widely used in various industries. This material is one of the most important and widely used cellulose derivatives, which has been considered in many researches as a substrate for the production ...
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Background and objectives: Carboxy methyl cellulose (CMC) is one the ether derivatives of cellulose and is widely used in various industries. This material is one of the most important and widely used cellulose derivatives, which has been considered in many researches as a substrate for the production of composite materials due to the presence of the carboxy methyl and hydroxyl groups. CMC can also be used as a substrate for the production of the magnetic cellulose compounds. Magnetic materials such as iron oxide are able to form effective bonds with hydroxyl groups in CMC and produce magnetic composites with biodegradable properties. The purpose of this research is to produce and analyze the magnetic properties of biocomposite made from CMC and then coat it on the surface of paper.Methodology: In this research, CMC was used as a substrate for the production of magnetic biocomposite. The in-situ synthesis was used to produce biocomposite. In the process, iron salts (4 and 6 H2O) and CMC were mixed together in an aqueous solution and under nitrogen atmosphere, then by adding ammonium hydroxide to pH 11, iron oxide particles (magnetite) were formed on CMC. The materials were stirred in water bath for 1 hour at 40 °C, in order to complete the reactions and increase the production efficiency of magnetic particles. Handsheets with 120 ± 5 g/m2 weight was prepared by using commercial kraft fibers, and then coated with magnetic biocomposite. The synthesized magnetic materials and coated paper with magnetic biocomposite were analyzed by X-ray diffraction. The size of iron oxide was tested by an atomic force microscope. Also, the morphology and surface characteristics of magnetic particles, magnetic biocomposite and coated fibers and paper were investigated by scanning electron microscope. The magnetic properties of the samples were evaluated with a vibrating magnetometer. Furthermore, the strengths properties of the coated paper were examined with tensile, tear, water absorption and air resistance tests.Results: The results of the magnetic test showed that in the first phase, the magnetic biocomposite was successfully prepared and the sample showed super paramagnetic properties. The highest magnetic saturation in the iron oxide sample was about 25 emu/g. Also, the CMC magnetic biocomposite had a magnetic saturation about 4 emu/g. The results of the microscopic evaluation of the iron oxide particles showed a uniform cubic structure. The formation of this structure is due to the accumulation of particles. In addition, mechanical engagement and connection of the magnetic biocomposite with the paper was observed. Also, the microscopic analyze of the iron oxide showed the most frequent of particles size were 45 nm. The results of the strength properties of the paper showed that the coating with magnetic material decreased the tensile and tear indices. The air resistance in the coated paper samples has increased compared to the control sample. Based on the results of Cobb test (water absorption), the lowest water absorption is related to the coated paper with CMC magnetic biocomposite. The X-ray diffraction pattern of the iron oxide sample showed five important peaks at 2 theta angles of 35, 41, 50, 67 and 74 degrees, which the main peaks indicated the iron oxide.Conclusion: The purpose of this research was to analyze the magnetic property in the CMC biocomposite and then coat it on the surface of the paper. Therefore, the experiments were carried out in 2 stages. In the first stage, CMC magnetic biocomposite was made by in situ synthesis process with iron salts. In the second phase, handsheet was prepared by using commercial kraft fibers and coated ones. The results of the testing samples showed the successfully production of magnetic biocomposite. Also, the paper coated with this material has suitable magnetic properties.
Pulp and paper
Seyed Mehdi Manzour-olajdad; Omid Ramezani
Abstract
Background and Objectives: Our country has been importing various kinds of wallpaper from different countries for many years. With the increase of foreign exchange problems, the local production of wallpaper and its self-sufficiency has been proposed as a suitable solution. On the other hand, currently, ...
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Background and Objectives: Our country has been importing various kinds of wallpaper from different countries for many years. With the increase of foreign exchange problems, the local production of wallpaper and its self-sufficiency has been proposed as a suitable solution. On the other hand, currently, domestic companies are producing paper from white waste paper, which is not justified for use as printing and writing grades due to many problems. However, many companies in the country are producing white grades from white waste paper, the use of which as a base paper in the production of decorative paper or wall paper has not been scientifically investigated. The purpose of this research is to study and investigate the possibility of producing wall paper from recycled white paper produced in the country.Methodology: The stages of this project were carried out in 6 separate and consecutive phases, which include: 1) determining the quality characteristics of the papers; 2) preparation of coating material formulation with starch as binder; 3) preparation of coating material formulation with latex and starch as binder; 4) coating of papers with the prepared coating formulations ; 5) Coating papers and non-woven fabric (Non-Woven) with polyvinyl chloride (PVC); 6) Application of four-color printing on the selected samples of coated papers. For this purpose, first, samples of papers produced by several Iranian companies were acquired and they were transferred to the laboratory of Biosystems and Bioproducts of Shahid Beheshti University for coating and performing the necessary treatments. In order to perform the mentioned treatment on the paper samples, various chemical substances were used, including calcium carbonate powder, kaolin, titanium oxide, corn starch, latex and PVC powder. With this aim, coating solutions with different percentage of solids were prepared steadily and with trial and error using various combinations of these materials (with a total of 110 and 124 parts). Then, these coated solutions were added on various domestic base papers (mostly recycled). Finally, the image of a flower was printed in four colors on the most desirable coated papers.Results: In determining the quality characteristics of base papers, including measurements of water absorption, ash content, thickness, permeability to air, tensile strength, tear resistance index and burst resistance index, two paper samples produced by two companies of Pardis Paper and Tabriz paper were selected as the best and considering the amount of ash, Tabriz paper was introduced as the base paper more suitable than other local papers. Further, after applying the coating material, coated papers with a relatively favorable appearance and whiteness percentages of about 60 to 85 were obtained, and finally, based on the results, a significant relationship was found between the increase in the solids percentage of the coated solutions and the whiteness percentage of the coated paper. Also, after the printing operation on the selected samples, Rasha Superkraft and Tabriz Kraft papers were introduced as the best samples. Also, the highest quality of printing was reached with PVC on Pars white paper with 16% PVC, on whitetop Rasha with 28% PVC and on non-woven fabric (non-woven fabric) with 28% PVC compared to the weight of the paper.Conclusion: The conclusion of the results of this research are listed below:A) The best solid percentage of coating solution (concentration of the mixture) was 41-46%.b) The best combination of binder and pigment, equal to 100 + 12 + 12 = 124 parts and the ratio of the dry weight of the coating mixture added to the dry weight of the base paper is equal to 12%.c) The highest whiteness obtained by adding calcium carbonate + titanium oxide + starch.t) The most suitable concentration of starch that can be used in the coating solution is 15%.c) The best coating and uniform and good coating appearance was obtained on Rasha Superkraft paper with the formula: kaolin + titanium oxide + latex with a whiteness of 77.7% and on Tabriz kraft paper with the formula: kaolin + titanium oxide + latex, with a whiteness of 71.8%. If higher whiteness is desired, using calcium carbonate instead of kaolin would give a better result.
Pulp and paper
Mehrnoosh Tavakoli; Ali Ghasemian; Mohammad Reza Dehghani Firouzabadi; Wojciech Grzeskowiak; Bartłomiej Mazela
Abstract
Background and objectives: The destructive effects of heat increasing in cellulose substrates, which are the basic materials for the packaging industries, high-quality hygiene packaging, and ammunition packaging, are obvious and inevitable. Therefore, it is essential to modify the structure of these ...
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Background and objectives: The destructive effects of heat increasing in cellulose substrates, which are the basic materials for the packaging industries, high-quality hygiene packaging, and ammunition packaging, are obvious and inevitable. Therefore, it is essential to modify the structure of these bio-based products with green and environmentally friendly materials, to increase their durability against heat.Methodology: In the current study, TEMPO-oxidized CNFs and CNCs, were initially and separately retarded using flame retardant mixtures, including dual “ammonium monophosphate+albumin”, “silica+methyltri-methoxysilane”, and quadruple “ammonium monophosphate+albumin+silica+methyltri-methoxysilane”. Using a rod coater, each combination was then coated individually on the produced cellulosic paperboards. Flame retardancy properties were evaluated by three thermal experiments, including a Mini Fire Tube, Limited Oxygen Index, and Mass Loss Calorimeter. Results: Based on the observed results, the role of mono-ammonium phosphate, due to the presence of phosphorus-containing groups as the driving force of the charring during combustion, was more prominent and significant in the dual coating mixture than the quadruple coating mixture, containing silica and phosphorus, both in the paperboards coated based on CNFs and paperboards coated based on CNCs. Comparison of the CNFs and CNCs based-flame retardant, as the main basis of the coating formulation, showed that paperboards coated with CNFs based-flame retardant, due to having amorphous and crystalline regions, had much lower amount of mass loss in the Mini Fire Tube test, almost similar Limited Oxygen Index, and Peak Heat Release Rate (PHRR) and Heat Release Rate (HRR) in the Mass Loss Calorimeter test, compared to those of the paperboard coated with CNCs based-flame retardant. Conclusion: In general, CNFs and CNCs based-flame retardants with mono-ammonium phosphate and albumin, even in low concentrations, can be used as effective retardants and replacements for conventional flame retardants, in high-quality cellulose-based packaging production.
Pulp and paper
Jafar Ebrahimpour Kasmani; Ahmad Samariha; Alireza Khakifirooz
Abstract
This research was conducted with the aim of investigating the effect of two-layer coating of nano-polyurethane and nano-clay on the mechanical and physical properties of packaging cardboard with brown layer. For this purpose, brown layer cardboard with grammage of 127 was prepared and tested. To coat ...
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This research was conducted with the aim of investigating the effect of two-layer coating of nano-polyurethane and nano-clay on the mechanical and physical properties of packaging cardboard with brown layer. For this purpose, brown layer cardboard with grammage of 127 was prepared and tested. To coat the surface of the cardboard, it was first coated with nano-polyurethane and sprayed by a coating nozzle. Then the surface of the brown layer cardboard was covered with nano-clay to improve the performance of the coating material of the first treatment. Nano-clay coating was performed by a laboratory coating machine called barcoter. The coated cardboards were restrained and dried in the room for one day to stabilize the coating material on their surface. Then the samples were placed inside the freezer for 2 and 4 months and their properties were measured. The results showed that coating reduced water absorption. In the coated and frozen samples, an increase in thickness, smoothness of the surface and a decrease in water absorption and resistance properties compared to non-frozen control samples have been observed. Double coated samples showed very few pores. The thickness, smoothness of the surface and resistance to tearing in the machine cross direction of the double coated brown cardboard showed an increase of 13.7%, 75% and 3.8%, respectively, compared to the control sample. water absorption, resistance to bursting, resistance to tearing in the machine direction, resistance to tensile in the machine direction, resistance to tensile in the cross machine direction, resistance to ring crush test in the machine direction and resistance to ring crush test in the cross machine direction of the double-coated brown layer cardboard compared to the control sample, showed 107.20, 1.5, 34.3, 25.4, 24.3, and 4.7 percent decrease respectively.
khadijeh armand; ali ghasemiyan
Abstract
This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan ...
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This study was carried out to determine the effect coating polylactic acid-chitosan complex on the packaging paper by two methods of mixing and grafting. For this purpose was made handsheet (80 g/m2) of long fibers that prepared from Mazandaran Wood and Paper Factory. Therefore, poly lactic acid, chitosan and nanocytosis with concentration of 1 wt% , were prepared by dissolving in chloroform and 1% acetic acid, respectively. In both method done coating with three layers. Then, coated samples dried in oven. In the mixing method, polylactic acid and chitosan were mixed then coated on base paper. In the grafting method, by chemical modification of chitosan and polylactic acid, 0.01 g of EDC( N-(3-dimethy laminopropyl)-N/-ethylcarbodiimide hydrochloride) , 0.1 g of Span 80 and 0.047 g of HOBT( 1- Hydoxybenzotriazole) homogeneous solution were prepared and placed on a paper surface. Finally, investigated barrier and mechanical properties including contact angle, water absorption, air permeability and burst strength respectively. The results showed that papers which were coated with grafting method, with three layers of coating (P3nCs3) had the most strength air permeability compared to the mixing method, control sample showed minimum strength to air permeability. Water absorption decreased in coated samples by mixing method compared to grafting method that showed grafting method further reduced water absorption. Contact angle increased in coated samples by the grafting method compared to the mixing method.
rouzbeh asadi khansari; Mohammadreza Dehghani Firouzabadi; Hossein Resalati
Abstract
The purpose of this research is to evaluate the effect of various paper coatings on initial contact angle and its evolution over time. We investigated nine coatings on two types of 75 g and 125 g printing papers. Seven coating compositions containing 80% clay, 20% ground calcium carbonate, dispersing ...
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The purpose of this research is to evaluate the effect of various paper coatings on initial contact angle and its evolution over time. We investigated nine coatings on two types of 75 g and 125 g printing papers. Seven coating compositions containing 80% clay, 20% ground calcium carbonate, dispersing agent and various levels of polyvinyl acetate and lactic acid as binders were used. In the last two coatings, we used 100% precipitated calcium carbonate pigments, cationic starch, methacrylate, dispersant and two levels of cellulose nanofibers. In these suspensions, the amount of cellulose nanofibers in composition 8 is twice composition 9. After coating using rod method, the papers were dried then coated and control samples were calendered. We then performed contact angle measurements using water droplet and Kit No were performed. We noticed largest contact angle and smallest angle change over time for sample 6 containing 75% binder. Last two coatings contained cellulose nanofibers, which caused presence of hydroxyl group on the surface and lowered the contact angle. Composition eight was the most hydrophilic sample. Best barrier property Kit No and largest droplet volume after 20 seconds was accompanied with the increase of the binder percentage in the formulation. For the control sample and three treatments with highest binders, the contact angle over time remains relatively constant which is a sign of hydrophobicity. The correlation between contact angle and volume of the water droplet was determined to be 0.951 and 0.936 in the 75g and 125g papers relatively. We did not notice a significant difference in contact angle and Kit No between 75g and 125g samples.
ali ghasemiyan; khadijeh armand; Elyas Afra; ahmad reza saraeian; mina salary
Abstract
The aim of this study was to investigate the effect of coating packing paper with polylactic acid-chitosan and polylactic acid-nano-chitosan complexes in two layer by layer and composite methods. For this purpose, was used of 80 grams long fiber handsheet paper Prepared from Mazandaran wood and paper ...
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The aim of this study was to investigate the effect of coating packing paper with polylactic acid-chitosan and polylactic acid-nano-chitosan complexes in two layer by layer and composite methods. For this purpose, was used of 80 grams long fiber handsheet paper Prepared from Mazandaran wood and paper factory. For the preparation of coating material, 1% poly lactic acid in chloroform and 1% chitosan and nano chitosan in acetic acid were prepared. In both methods, up to three layers of coating were finally applied and the final layer in each treatment was poly lactic acid. The paper samples were then dried in an oven at a temperature of about 100 ° C. In the composite method, each material (chitosan and nano-chitosan) was mixed independently with poly lactic acid on a magnetic stirrer and then seating on a base paper. Finally, all papers were performed for barrier tests including contact angle measurement, water absorption (Cobb) and water vapor transmission rate (WVTR) and resistance tests including burst resistance and air penetration resistance. Based on the results, the barrier properties of the coated Samples in both methods (layer by layer and composite) were increased compared to the control sample. Also, the results of the study of composite and layer by layer methods showed that the LBL method causes more prohibition in the paper and increases the amount of prohibition with increasing the number of coating layers. It is worth noting, however, that between the second and third layers of coating, changes were less pronounced. These changes were observed in both the LBL and composite methods. Air Resistance was also increased in the coated samples.
Pulp and paper
ali barzan; hossein resalati; ali ghasemian; ahmadreza saraeyan; ghasem asadpour
Abstract
In this study, the effect of pigment composition on the properties of paper prepared from CMP pulp was studied. There for 3 different pigment combinations (100% calcium carbonate (GCC), 70% calcium carbonate and 30% kaolin clay (70GCC30Clay) and 70% calcium carbonate and 25% gritty and 5% titanium dioxide ...
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In this study, the effect of pigment composition on the properties of paper prepared from CMP pulp was studied. There for 3 different pigment combinations (100% calcium carbonate (GCC), 70% calcium carbonate and 30% kaolin clay (70GCC30Clay) and 70% calcium carbonate and 25% gritty and 5% titanium dioxide (70GCC25Clay5TiO2)) were made with anionic starch, latex and dispersersant and Used for coating. Physical properties included (surface roughness of the paper, Ash content and Apparent density) And the optical properties included (brightness, absorption and diffusion coefficient) and paper resistance characteristics including tensile strength, bursting resistance, tear strength based on standard TAPPI standardized measurements and Using factorial design, analysis of variance was performed and the mean of paper properties was compared with Duncan's test. The purpose of this research is to achieve the best combination for coating the paper with the improvement of physical and optical properties and maintaining resistance properties. By adding clay and dioxide titanium to calcium carbonate, the roughness of the paper surface decreased The highest roughness of the surface of the paper in the diet was observed for the control paper and the lowest was seen in the treatment of 70GCC30Clay surface. Also, the highest degree of brightness is related to 70GCC25Clay5TiO2 treatment. The highest index of tensile strength and burst strength index was related to gypsum treated paper (GCC) and also the highest tear strength index for treated paper at level 2 (70GCC30Clay).
Pulp and paper
Bardia Sodeifi; noureddin Nazarnezhad; Seyed Hassan Sharifi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1576.1610 In this research, the effect of coating with Polycaprolactone (PCL), nanocrystalline Cellulose (NCC) and zinc oxide Nanoparticle (ZnO NP) and their blend were investigated on the mechanical and optical properties. First, coating materials with specific condition (PCL 10%, NCC 4 and 6%, ZnO 3%) were coated on the papers. The coating materials weight on the papers was (2.2- 2.7 g/m2). The results showed that the mechanical properties (Tensile strength index, Burst strength index and Tear strength index) of the coated papers were enhanced with addition of NCC. The ternary blend of these coating materials had the best mechanical properties than the neat paper. With addition of NCC the brightness were enhanced and the opacity were reduced. Also, the color properties were improved with addition of NCC and ZnO and the effect of ZnO was more remarkable than NCC but, in ternary blend of materials, the color properties were improved with increasing the amount of NCC.
Management and Economics wood
Seyed Mahmoud Miri Tari; asghar tarmian; Mohammad Azadfallah; Abdolkhani Ali; Davood Efhamisisi
Abstract
DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent ...
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DOR:98.1000/1735-0913.1398.34.45.66.1.1575.1575 Mold growth resistance of Polyurethane and Diotrol coatings containing natural (Thyme essential oil) and synthetic (IPBC) fungicides in both free and microencapsulated forms was studied. Polymethyl methacrylate (PMMA) microcapsules were prepared using solvent evaporation method by means of oil emulsion formation in water. Mold growth resistance against Aspergillus niger was determined by Filter Paper Disc method before and after aging process according to ASTM D 5590 Standard. Adhesion strength and surface roughness of coated samples were also measured. Results revealed that biocide-free coatings cannot provide adequate protection against mold growth, and addition of biocides, especially IPBC, significantly improved the mold growth resistance. Even after the aging process, microencapsulated biocides were able to provide better protection against mold growth due to controlled-release mechanism and shielding-effect of polymeric shell. Although the surface roughness of polyurethane coating was increased by using of biocides in both forms, especially microencapsulated ones, its adhesion strength reduced.
Pulp and paper
masoumeh mollaei; Mohammad Azadfallah; Yahya Hamzeh; faramarz khodaian chegini
Abstract
The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. ...
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The Effect of Chitosan - Poly (vinyl alcohol) Coatings on Strength and Barrier Properties of Packaging PaperAbstract In this research the mechanical and barrier properties of hand-sheets made of virgin and recycled fibers were studied after coating by chitosan and poly (vinyl alcohol) polymer blends. Therefore to evaluate coatings effects on barrier properties, water vapor transmission rate (WVTR), water absorbance, air resistance and grease proof of coated papers were determined. Moreover, mechanical strength including tensile strength and burst strength were measured. According to the results, the barrier properties and mechanical strength of coated papers improved dramatically than uncoated ones. The best results in WVTR and mechanical strength tests were obtained for coatings with the same ratio of polymers. On the other hand, coating with 75%chitosan - 25% poly (vinyl alcohol) composition exhibited excellent resistance against the grease penetration and water absorption.Keywords: Coating, chitosan, poly (vinyl alcohol), barrier properties, mechanical strength
