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The blend (wax M) of crude by-product polyolefin wax (wax K) and a fractionated commercial paraffin wax (wax J) was suggested to replace the wax J as a coating agent for wax-coated papers. The rheological properties of waxes J, K, and M were examined and compared. The correlation between viscosity and shear rate applied on these waxes maintained at 90 oC and 130 oC was identified. In particular, this paper, for the first time, presented non-Newtonian shear thinning behavior of not only wax K but also its blend of wax M in terms of their viscosity affected by shear rate at an operating temperature below their melting temperature of higher-melting-temperature DSC endothermic peaks (HMTEPs). They showed non-Newtonian behavior, so-called shear thinning behavior, at 90 oC in the light of characteristics of both suspension systems and polymer systems. In addition, the profiles of viscosity at 130 oC of all the waxes versus the shear rate exhibited Newtonian fluid behavior. Wax J also showed the behavior of a dilatant fluid. Then, the physical properties including water vapor transmission rates (WVTR), surface roughness, and coated weights, of thin papers coated with waxes J (WJP), K (WKP), and M (WMP) were evaluated, characterized, and compared. As a result, WMP had an equivalent value to that of WJP or the lowest value among wax-coated papers in terms of WVTR. The surface roughness and the barrier property of WVTR were minimized and enhanced, respectively, by blending waxes J and K. The additional physical properties, including dynamic contact angles, surface tension, wet and dry tensile strength, optical examination of the wax-coated fiber structure, and antimicrobial properties of the wax-coated papers, were evaluated. The excellent antimicrobial properties of clinoptilolite added to wax J or wax M appeared.

Dual-purpose coated paper, which enables in-line inkjet printing with web offset, can be used for both offset and inkjet prints. This product has potential to meet the ever-increasing demand for printing individualized information on commercial printing materials. In this work, commercial samples were printed in the two presses. It was deduced that low permeability correlates with large color gamut volume. The correlation would be useful to design coating formulations for good printability. Also, we examined the packing of coating layers to identify a coating formulation that provides good printing quality in both offset and inkjet printing. Many combinations of pigments were tested, and the effects of particle shape on viscosity and packing were examined. For all coating colors, pigment mixtures with a weight ratio of 3:1 gave the highest packing density. The mixture of GCC 90 and delaminated clay with a weight ratio of 3:1 was the best selection studied for dual-purpose coated paper. Among commercial paper samples, a web offset coated paper showed the best overall performance, indicating that coating formulations with minimal blistering are suitable for dual-purpose coated paper.

The packaging industry is one of the pioneering industries facing many challenges during the production cycle. Migration of printing ink in packing items is the harmful problem for customer, Therefore, this study aims to reduce the penetration of ink into the product, one of the unavailable technologies is coating printing substrates with a polymer layer. Ecofriendly Super hydrophobic coating was prepared in aqueous medium based on silicon dioxide and characterized with particle size analyzer Dynamic laser scattering )DLS( and zeta potential. Paper duplex 180 g/m2 were coated with prepared superhydrophobic Nano coating through spray coating with emulsion solution. The coated paper sheets were printed by lithooffist and testes by X-rite instrument. This polymer can seal the pores of the printing materials. It is also a barrier to prevent the leakage and deportation of ink particles into the packaging that can occur in various raw materials, especially untreated materials as well as. One of the advantages of this polymer is to reduce the penetration of ink consumed for printing, that is, it is of double benefit, which is protection and reduce ink penetration, and the research results show the effective use of this polymer layer, whether in roughness, water absorption, Ink penetration and printing properties

Biodegradable coated paper materials represent one of the most promising alternatives to petroleum-based materials, including plastics and plastic-paper composite materials. Herein, fully biodegrad...

Optical Density is one of the important parameters used to control print quality. Optical density in print materials is form of interaction of ink with paper. This research is oriented to the investigation of optical density value of Yellow printing ink on coated and uncoated paper. The main purpose of this study is to analyze the effect of printing ink thickness on optimal density value. The optical density value of yellow prints obtained using densitometer measurement, printed using IGT method on coated and uncoated paper. Ink thickness variations are applied (0.8 - 9.6 μm). Density values was found to increase as the ink layer thickness increased to a certain point called the optimal density (2.4 μm ink thickness on coated paper and 4.5 μm on uncoated paper). Optical density of yellow printing ink on coated paper is higher uncoated paper, which relates to porosity on paper

With the increasing popularity of coated paper, it has been more widely used in printing, publishing, product packaging and commercial promotion. However, coated paper is prone to cracks after printing and folding which exposes to a white area which is referred to as fold cracking. This study investigated the coating properties of paper and coating factors influencing the fold cracking and aimed to provide guidance on how to reduce the problems of fold cracking. This paper mainly discusses the effects of pigment proportion, binder dosage, solids content, coating thickness and calendering pressure on fold cracking of coated paper after printing. Experiments show that when the coating consisted entirely of calcium carbonate, the degree of fold cracking is most serious. With the addition of kaolin, the fold cracking reduces. When the ratio of the number of parts of calcium carbonate to kaolin is 25/75, the area of fold cracking reaches its minimum value of 10.28 %. With increasing solids content of the coating, the fold cracking decreases initially and then increases. When the solids content is 55 %, the fold cracking reaches a minimum. Increased latex content reduced coating thickness and an increase in calendering pressure gradually reduce the degree of fold cracking.

In the packaging sector of the printing industry, different coating applications are tried and investigated in order to increase the surface appearance and performance characteristics of paper and cardboard. The printability, water and ink absorption capacity, frictional resistance, light sensitivity of the visual graphical design that are going to be printed on the packaging papers are some of them. In this study, different types of cardboards that are used as a packaging material were chosen and coated with nanocrystalline cellulose (NCC)/PVA at different rates (%). In order to determine effective and economical usage conditions, the coating solutions, at three different concentrations as 3 wt.%, 5 wt. %, 7 wt.%, were prepared. The coating was applied on the test papers, which were at the same weights (350 g/m2) and had different surface properties as matte glossy, bright glossy, American Bristol. NCC/PVA existence on the coated paper surface was confirmed with Fourier Transform Infrared Spectroscopy (ATR-FTIR). The impact of the coating, which was prepared at different concentrations, on the packaging materials was studied with respect to thickness, stiffness, water absorbability, contact angle and surface tension.

Coatings based on pigment and polymer binders are applied on paper surfaces to improve their surface, optical, and printing properties. Besides the coating composition, the structure and properties of the coated papers are influenced by the coating layer consolidation upon drying. In this study, the influence of drying conditions on the structure and properties of coating layers based on natural pigments (clay) and polymer binders (butadiene acrylonitrile latex) has been analyzed. Using a laboratory rod Mayer device, the coatings were applied as thin layer (about 15&ndash, 16 g/m2) on the paper surface and samples of coated paper were dried at 20 and 105 &deg, C temperatures. The optical, structural, and water absorption properties of the coating layer were evaluated by the measurement of gloss, opacity, void fraction, light scattering, and contact angle. The obtained results highlighted that both the drying temperature and latex content in the coating color have a synergic effect on the coated paper quality.

To study the influence of different concentrations of zinc oxide (ZnO)/silicon dioxide (SiO2) composite coating on hydrophobic property and mechanical stability of paper mulch film, three kinds of ZnO/SiO2 composite coating paper mulch films (2%, 4%, 6%) with different coating substance contents were prepared by brush coating method. Through particle size analysis, contact angle, rolling angle and mechanical stability test, combined with scanning electron microscope, three-dimensional morphology and roughness measuring instrument, the optimal concentration of ZnO/SiO2 composite coated paper mulch film was screened out. Through acid-base salt corrosion test, silver mirror reaction and surface self-cleaning, the optimal concentration of composite coated paper mulch film was compared with the original paper mulch film to prove its excellent chemical stability and hydrophobicity. The results show that the paper mulch film with 4% coating material has excellent hydrophobicity and mechanical stability, can effectively reduce the surface roughness of paper mulch film, and has remarkable effects in resisting acid, alkali and salt and self-cleaning.

This study characterizes and compares the parameters of the quality reproduction of fine elements in flexography on coated and uncoated paper as well as on OPP film (oriented polypropylene). A monochrome test form was created and printed using cyan UV ink. The analysis of results confirms the importance of interaction between the printing substrate and ink, it also indicates identical line and text deformations on the print. Quality reproduction on coated paper is higher in relation to OPP film for all the research parameters. The ink penetrates significantly more and with more irregularity into the pores and throats of the uncoated paper, which results in less homogeneous elements, and in such way that it loses its original shape. In coated paper and OPP film, the ink spreads more on the substrate area which gives it a significantly more homogeneous shape. However, due to the surface spread of the ink, the biggest changes in the size of fine elements are noticeable in the OPP film. The scientific contribution of this paper is based on the comparison of print quality parameters of fine elements, which can contribute to the optimization of the production process and quality of the final graphical product.

The use of clay filler materials in dispersion coatings is a well-established method to provide improved barrier properties to the coated paper substrate, in particular lowering the water vapour transmission rate (WVTR) through the coating. In this paper we demonstrate the use of small spherical silica particles (∼100–220 nm) as an additive to a clay-latex coating formulation is able to provide further improvements to the barrier properties, when compared to the equivalent silica-free coatings. A significant decrease in both the water vapour transmission rate and the direct water uptake of water ( Cobb 120 {\text{Cobb}_{120}} wettability test) is observed for coatings containing as little as 1 % silica additive.

Cellulose is one of the constituents of plants and is an environmentally friendly resource with a semi-permanent supply and high biodegradability. CNF from cellulose is useful for various purposes. CNF has high aspect ratio and high specific surface area and it is excellent in mechanical properties and thermal stability, and it has shear-thinning flow characteristics. When CNF is coated on paper, it provides high barrier property with excellent network forming ability. The surface roughness of the coated paper is one of the characteristics that determine the quality of coated paper and printing. The surface roughness is measured by the stylus profiling, the air leak, and the optical image analysis methods. Each analysis method has certain characteristics, so surface roughness of coated paper was analyzed by those three methods and results were compared. After mixed coating of CNF and oxidized starch, the degree of roughness was increased in the probe method and the air leakage method when the coating weight and the amount of CNF were increased. The degree of roughness which is measured by Optitopo decreased when the mixed solution was coated. Because the range of roughness measured by each measurement method is different, it might give different tendencies.

The current open-loop practices employed to render paper substrates water- and oil-repellent for packaging and non-packaging applications have generated ocean pollution and have placed daunting burdens on landfills. In this study, we report a green, unique and facile approach for the fabrication of grease- and water-resistant paper products with 100% recyclability of the paper pulp. Low surface energy polydimethylsiloxane (PDMS) was grafted onto a biobased chitosan polymer via urea linkages to prepare the graft copolymer chitosan-graft-polydimethylsiloxane (chitosan-g-PDMS). Chitosan-g-PDMS was then applied as a coating onto an unbleached Kraft paper substrate from an aqueous solution. The coated paper substrates exhibited good hydrophobic properties with a water contact angle of 120.53 ± 0.96° and a Cobb 60 value of 9.89 ± 0.32 g m−2. The coated paper substrates also showed good oil-resistance as evident from the kit rating value of 11.7/12. The tensile strength, crushing resistance, bending stiffness, and internal tearing resistance of the paper before and after coating treatment was determined. Scanning electron microscopy (SEM) analysis was used to characterize changes in the porosity of the paper before and after the coating. The pulp recyclability of the coated paper was validated by subjecting the coated paper samples to repulping and washing treatment. This novel and practical approach can provide significant environmental benefits by offering plastic-free, fluorine-free and fully-recyclable water- and grease-resistant paper; thus promoting sustainability due to its unique closed-loop nature.

The pore structure of the coating layer is one of the most important factors in determining the printability of coated papers. The coating pigment and binder are two principal components in paper coating, and their characteristics have a critical influence on the coating structure. The glass transition temperature (Tg) of latex binders affects the mechanical strength and pore structure of the pigment coating layer because the latex Tg influences the binding ability of latex and the shrinkage of the coating layer during the drying process. In this study, styrene-acrylate (S/A) core-shell structure latexes with different monomer compositions in the core and shell layers were designed, and their properties were compared with those of a conventional latex. These core-shell latexes were prepared using the same monomers in the same proportion and were used to investigate the effect of the core-shell structure on the structural and mechanical properties of the coating layer. The hard-shell latex with a high styrene content in the shell part yielded paper that was glossier and less rough and formed finer pores, resulting in an increased ink absorption rate into the coated paper compared to the other types of latex. The hard-shell structure showed better performance in printing uniformity and had less mottling.

Solar-reflective thermal insulating coating (SRC) has received great attention because of its desired heat reflective properties and water repellency, which may impart high-value to cellulosic paper via industrially well-established surface coating process. However, the feasibility and possibility of surface application of SRC to cellulosic paper have not been explored. Herein, in the present work, SRC was designed/developed and subsequently used in the surface application to cellulosic paper. Effect of feeding level of titanium dioxide nanoparticles (nano-TiO2) on rheological behavior of the coating, as well as heat-reflective properties, water repellency and mechanical properties of the surface-coated paper was studied. Results showed that the as-obtained coating samples exhibited a notable shear-thinning behavior and displayed strong dependence of rheological behavior on nano-TiO2 amount. Furthermore, the increased nano-TiO2 amount appeared to induce the improved hemispherical emittance of coated paper. The coating weight was also found to exert a positive effect on the hemispherical emittance of coated paper. In addition, it was confirmed that the nano-TiO2 addition played an important role in improving the water repellency and mechanical properties of coated paper.

Here, we report a non-toxic method for improving the oil-resistant performance of chitosan coated paper by coating the mixture of chitosan and montmorillonite (MMT) instead of coating chitosan solution only. Through combining MMT into the chitosan coatings, the coated paper exhibited a lower air permeability and enhanced oil resistance under a lower coating load. For coated papers C2.5 and C3 by coating 2.5% (w/v) and 3% (w/v) chitosan without adding MMT in the chitosan coating, the coating load was 3.76 g/m2 and 3.99 g/m2, respectively, and the kit rating values were only 7–8/12. Regarding the sample C2M0.1 coated by the mixed solution containing 2% (w/v) chitosan and 0.1% (w/v) MMT, its coating load was only 3.65 g/m2, the paper permeability after coating was reduced to 0.00507 μm/Pa·s, owing to the filling of MMT into the cellulosic fibers network, and the kit rating reached 9/12. Moreover, C2M0.1 showed improved mechanical properties, whereby its tearing resistance was 5.2% and 6.6% higher than that of the uncoated paper in the machine direction and the cross direction, respectively.

The poor barrier properties and hygroscopic nature of cellulosic paper impede the wide application of cellulosic paper as a packaging material. Herein, a polyvinyl alcohol (PVA)-based polymer coating was used to improve the barrier performance of paper through its good ability to form a film. Alkyl ketene dimer (AKD) was used to enhance the water resistance. The effect of the absorptive characteristics of the base paper on the barrier properties was explored, and it was shown that surface-sized base paper provides a better barrier performance than unsized base paper. Nanoclay (Cloisite Na+) was used in the coating formulation to further enhance the barrier performance. The results show that the coating of PVA/AKD/nanoclay dispersion noticeably improved the barrier performance of the paper. The water vapor transmission rate of the base paper was 533 g/m2·day, and it decreased sharply to 1.3 g/m2·day after the application of a double coating because of the complete coverage of the base paper by the PVA-based polymer coating. The coated paper had excellent water resistance owing to its high water contact angle of around 100°. The grease resistance and mechanical properties of the base paper also improved after coating. This work may provide inspiration for improving the barrier properties of packaging paper through the selection of a suitable base paper and coating formulation.

Coated paper with a porous coating layer may have enhanced light-scattering ability and thus favorable optical properties. However, the increased porosity of such a coating layer is likely to decrease the strength of the coated paper, thereby adversely affecting the quality of the paper in the printing and converting processes. In this research, polymer-stabilized (PS) latex was prepared and used as a cobinder for the pigment coating of the paper. The PS latex particles were colloidally stabilized by a 3:1 mixture of starch and polyvinyl alcohol. The influence of the PS latex cobinder on the viscosity, sedimentation, and consolidation of coating colors was investigated. In addition, the effect of the cobinder on the properties of coating layers, namely, their porosity and surface, optical, and tensile properties, was examined. The results revealed that the PS latex cobinder formed microstructures in the coating colors and affected their viscosity. The addition of PS latex also led to enhanced interactions between coating color components, which affected the consolidation of the coating color, resulting in the formation of dried coating layers with greater porosity and improved optical properties (i.e., higher brightness and opacity) relative to coatings without the PS latex cobinder. Furthermore, the addition of PS latex improved the tensile strength of the coating layers, which was attributable to the small size and the polymeric protective shell of the cobinder particles. Thus, these results show that this PS latex cobinder has the potential to be used for the production of high-quality coated paper products.

In order to evaluate the printing effect of self-made on-demand ink-jet printing ink and to study its influencing factors, its printing suitability and the influence of different substrate on its performance were studied in this paper. The drying process of ink on different paper was tested by contact angle tester. The color reproduction performance of self-made ink and common ink-jet ink was compared by measuring the printing samples of ink on different substrates with spectrodensitometer. The experimental results showed that the absorption rate of ink on offset paper was the fastest compared with that of coated paper and photo paper, and the drying time of self-made ink on substrate was shorter than that of ordinary ink-jet ink, which was basically volatilized and permeated in 2–3 s on offset paper. In terms of color reproduction performance, two kinds of three primary color inks could reproduce the better color of the image on the coated paper. The color strength of the self-made three primary color inks on the offset paper and the coated paper was higher than that of the ordinary ink-jet ink and the color hue error was smaller, so the color reproduction performances on the paper were better.

Functional microcapsule refers to a small container in which solid, liquid or gas are wrapped by natural or synthetic polymer materials to form a core-shell structure. Meanwhile, the corresponding functional ink can be obtained by combining functional microcapsule with ink. In this study, thermal expansion and aromatic slow-release functional microcapsules were formulated at a certain ratio with colorants and binders to obtain a composite microsphere ink with aromatic expansion effects. Based on this, the functional microcapsule ink is transferred to five kinds of different flexible printing substrates such as cotton, non-woven fabric, kraft paper, offset paper and coated paper by screen printing, and the impact of binder on ink printability is mainly investigated. Moreover, the surface morphology, foaming height, adhesion of printed products and thermal stability of printing ink were characterized by laser confocal microscope, thickness gauge and thermogravimetric analyzer. At the same time, the printing effects of functional microcapsule ink on different substrates were evaluated and the ink formula was adjusted. Finally, a functional printed product with long-lasting fragrance and three-dimensional effect is obtained.

The object of the research is the processes of adhesion structural parts of integral and semi-rigid covers with bookbinding adhesives using continuous and discrete methods of applying adhesive. The conducted experimental studies are based on the use of a comparative technique for measuring the rigidity of double glued and double without adhesion binding materials by determining objective indicators of destructive pressure. The main assumption of research is that the use of various types of bookbinding adhesives applied in continuous and discrete layers will contribute to the formation of additional structural strength of the produced covers. This can’t be achieved without analysis and selection of adhesive polymer compositions from those widely used in bookbinding processes, taking into account the structural strength of the covers acquired after adhesion with these compositions. It is proposed to use fragments of integral and semi-rigid covers, made of high-quality coated papers of various weights, in an amount sufficient to obtain the confidence indicators of the study. As a result of experimental studies of glued coated paper samples, an increase in the relative indicators of structural strength is revealed, caused by the physicochemical effect of various types of adhesives. The features of the application of adhesive polymer compositions on the glued fragments of covers by continuous, tape and checkerboard methods are revealed. Analysis of double glued with a continuous layer of cover fragments, in comparison with double non-glued fragments, showed a significant increase in the relative structural strength of the glued fragments in a wide size range. It is determined that the discrete commensurate deviation of the obtained indicators is caused by the properties used for the research of adhesives. Comparative analysis of glued fragments of covers by tape and checkerboard methods of adhesion application revealed a significant difference in the experimental strength indicators obtained, towards a significant advantage of the checkerboard method. This, in addition to ensuring the structural strength of the glued fragments of the covers, close to the continuous method of applying the adhesion, contributes to a significant reduction in its expenditure component. The results of studies to determine the influence of a sample of binding adhesives, common in the technological processes of manufacturing book products, on the structural strength of integral and semi-rigid covers, to contribute to the planning of resource-saving technological processes., Об’єктом дослідження є процеси склеювання конструктивних деталей інтегральних і напівжорстких обкладинок палітурними клеями із застосуванням суцільних і дискретних способів нанесення клею. Проведені експериментальні дослідження ґрунтуються на застосуванні порівняльної методики вимірювання жорсткості подвійних клеєних і подвійних без проклеювання палітурних матеріалів через визначення об’єктивних показників руйнівного тиску. Основне припущення дослідження полягає в тому, що використання різних видів палітурних клеїв, нанесених суцільними та дискретними шарами, сприятиме утворенню додаткової структурної міцності виготовлених обкладинок. Цього неможливо досягнути без аналізу та обирання клейових полімерних композицій із широко використовуваних в палітурних процесах, з врахуванням набутої після склеювання цими композиціями структурної міцності обкладинок. Запропоновано для проведення досліджень використати фрагменти інтегральних і напівжорстких обкладинок, виготовлених із високоякісних крейдованих паперів різної маси, в кількості достатній для отримання довірчих показників дослідження. В результаті проведених експериментальних досліджень клеєних зразків крейдованого паперу виявлено зростання відносних показників структурної міцності, викликане фізико-хімічним впливом різних видів клеїв. Виявлені особливості нанесення клейових полімерних композицій на клеєні фрагменти обкладинок суцільним, стрічковим і шаховим способом. Аналіз подвійних клеєних суцільним шаром фрагментів обкладинок, у порівнянні з подвійними неклеєними фрагментами, показав суттєве зростання відносної структурної міцності клеєних фрагментів в широкому розмірному діапазоні. Визначено, що дискретне розмірне відхилення отриманих показників викликане властивостями, застосованих для проведення досліджень клеїв. Порівняльний аналіз клеєних фрагментів обкладинок стрічковим і шаховим способами нанесення клею виявив суттєву відмінність отриманих експериментальних показників міцності, в сторону значної переваги шахового способу. Це, окрім забезпечення структурної міцності клеєних фрагментів обкладинок, наближеної до суцільного способу нанесення клею, сприяє суттєвому скороченню його витратної складової. Отримані результати досліджень визначення впливу вибірки палітурних клеїв, поширених в технологічних процесах виготовлення книжкової продукції, на структурну міцність інтегральних і напівжорстких обкладинок, сприятимуть плануванню ресурсозберігаючих технологічних процесів., Объектом исследования являются процессы склеивания конструктивных деталей интегральных и полужестких обложек переплетными клеями с применением сплошных и дискретных способов нанесения клея. Проведенные экспериментальные исследования основываются на применении сравнительной методики измерения жесткости двойных клееных и двойных без проклейки переплетных материалов путем определения объективных показателей разрушительного давления. Основное предположение исследования заключается в том, что использование различных видов переплетных клеев, нанесенных сплошными и дискретными слоями, будет способствовать образованию дополнительной структурной прочности изготовленных обложек. Этого невозможно достичь без анализа и выбора клеевых полимерных композиций из широко используемых в переплетных процессах, с учетом приобретенной после склеивания этими композициями структурной прочности обложек. Предложено для проведения исследований использовать фрагменты интегральных и полужестких обложек, изготовленных из высококачественных мелованных бумаг различной массы, в количестве достаточном для получения доверительных показателей исследования. В результате проведенных экспериментальных исследований клееных образцов мелованной бумаги выявлен рост относительных показателей структурной прочности, вызванный физико-химическим воздействием различных видов клеев. Выявлены особенности нанесения клеевых полимерных композиций на клееные фрагменты обложек сплошным, ленточным и шахматным способом. Анализ двойных клееных сплошным слоем фрагментов обложек, по сравнению с двойными фрагментами без клея, показал существенный рост относительной структурной прочности клееных фрагментов в широком размерном диапазоне. Определено, что дискретное соразмерное отклонение полученных показателей вызвано свойствами применяемых для проведения исследований клеев. Сравнительный анализ клееных фрагментов обложек ленточным и шахматным способами нанесения клея обнаружил существенное отличие полученных экспериментальных показателей прочности, в сторону значительного преимущества шахматного способа. Это, кроме обеспечения структурной прочности клееных фрагментов обложек, приближенный к сплошному способу нанесения клея, способствует существенному сокращению его расходной составляющей. Полученные результаты исследований определения влияния выборки переплетных клеев, распространенных в технологических процессах изготовления книжной продукции, на структурную прочность интегральных и полужестких обложек, способствует планированию ресурсосберегающих технологических процессов

Materials for electronics that function as electrical and/or thermal conductors are often rigid, expensive, difficult to be sourced and sometimes toxic. An electrically and thermally conductive nanocomposite that is lightweight, flexible and eco-friendly could improve the environmental friendliness of the electronics sector and enable new applications. Considering this, we have fabricated electrically and thermally conductive flexible materials by functionalizing paper with nanocarbon conductive inks. Carnauba wax is emulsified in isopropyl alcohol and mixed with graphene nanoplatelets (GNPs) or with hybrids of GNPs and carbon nanofibers (CNFs). The percolation threshold of the hybrid samples is lowered compared with the pure GNPs composites, due to their increased filler aspect ratio. The hybrid samples also exhibit superior bending and folding stability. Densification of the coating to decrease their sheet resistance enables them to achieve as low as ~ 50 {\Omega} sq-1 for the GNP-based paper. The densification procedure improves the bending stability, the abrasion resistance, and the electromagnetic interference shielding of the paper-based conductors. Finally, the compressed samples show an impressive enhancement of their thermal diffusivity. The flexible and multifunctional nanocarbon coated paper is a promising electronic conductor and thermally dissipative material and, at the same time, can increase the environmental sustainability of the electronics sector., Comment: 27 pages, 4 figures

Due to the high electric conductivity and large surface area of nanographites, such as graphene and graphite nanoplatlets, these materials have gained a large interest for use in energy storage devices. However, due to the thin flake geometry, the viscosity of aqueous suspensions containing these materials is high even at low solids contents. This together with the use of high viscosity bio-based binders makes it challenging to coat in a roll-to-roll process with sufficient coating thickness. Electrode materials for commercial energy storage devices are often suspended by organic solvents at high solids contents and coated onto metal foils used as current-collectors. Another interesting approach is to coat the electrode onto the separator, to enable large-scale production of flat cell stacks. Here, we demonstrate an alternative, water-based approach that utilize slot-die coating to coat aqueous nanographite suspension with nanocellulose binder onto the paper separator, and onto the current collector as reference, in aqueous metal-free supercapacitors. The results show that the difference in device equivalent series resistance (ESR) due to interfacial resistance between electrode and current collector was much lower than expected and thus similar or lower compared to other studies with a aqueous supercapacitors. This indicates that electrode coated paper separator substrates could be a promising approach and a possible route for manufacturing of low-cost, environmentally friendly and metal-free energy storage devices.

A simple formulation of an organic-inorganic composite for spray-coating was adopted toward photoluminescent paper sheets. The coating composite layer was composed of a synthetic organic adhesive binder mixed with an inorganic lanthanide-doped strontium aluminate pigment. Such pigment-binder formula was applied effectively onto paper sheets via spray-coating followed by thermal fixation. The applied transparent photoluminescent coated layer exhibited optimal excitation wavelength at 365 nm and emission band at 517 nm resulting in phosphorescence of the paper surface with a substantial development of green-yellow, bright white, turquoise, and off-white colors as indicated by CIE Lab color coordinates under ultraviolet irradiation. The mechanical, decay and lifetime properties of the composite photoluminescent coated layer were described. The standard techniques of morphological properties and elemental analysis were explored by scanning electron microscope (SEM), wavelength dispersive X-ray fluorescence (WDXRF), and energy dispersive X-ray spectroscopic analysis (EDX). The spray-coated paper sheets demonstrated good fastness to light and reversible phosphorescence without fatigue.

Coated paper is an example of a multi-layer porous medium, involving a coating layer along the two surfaces of the paper and a fibrous layer in the interior of the paper. The interface between these two media needs to be characterized in order to develop relevant modeling tools. After careful cutting of the paper, a cross section was imaged using focused ion beam scanning electron microscopy. The resulting image was analyzed to characterize the coating layer and its transition to the fibrous layer. Such image analysis showed that the coating layer thickness is highly variable, with a significant fraction of it being thinner than a minimum thickness required to keep ink from invading into the fibrous layer. The overall structure of the coating and fibrous layers observed in this analysis provide insights into how the system should be modeled, with the resulting conclusion pointing to a specific kind of multi-scale modeling approach.

The apparent thermal conductivity of several insulation materials was measured over a range of temperatures. A newly developed multilayer reflective insulation system called Mirrorpanel was tested against existing products. Mirrorpanel samples were prepared using layers of aluminum foil (emissivity of 0.11) and coated paper (emissivity of 0.52) separated by air spaces of approximately 5 mm, with fiberboard structural spacers. Steady-state heat flux was measured in the laboratory for 500 mm × 500 mm samples including several Mirrorpanel configurations as well as expanded polystyrene and polyisocyanurate foam insulations. The mean temperature ranged between 0 °C and 35 °C with a temperature difference across the sample of 10 °C. For all insulation materials, the apparent thermal conductivity increased linearly with temperature above 5 °C, and the slope was steeper for the Mirrorpanel samples than the foam insulations. The apparent thermal conductivity of the Mirrorpanel made from aluminum foil was greater than that of polyisocyanurate but less than that of expanded polystyrene. The significant difference of thermal conductivity of lower and higher emissivity reflecting layers highlighted the importance of this parameter in thermal insulation. The steep temperature dependence of the Mirrorpanel should be considered during design of the building envelope for summer and winter conditions.

Traditional ink owning harmful components has caused many problems, so this paper developed chitosan-TiO 2 edible inks and used it as the model to study the relationship between rheology and printing, for better development of edible inks. Rheological properties and the corresponding fitting were investigated. The developed ink exhibited non-Newtonian behavior, shear-thinning behavior, and temperature-dependent properties. Shear strain, frequency and temperature had great impact on modulus of inks. Low J ( t ) (compliance) values reflected strong material structure and the related final recovery ratio attained 65.9%. Based on the fitting results, the screen-printing simulation were further researched for closer practical application. The recovery rate reached 55% with high initial recovery coefficient (K 3 = 10.7), indicating that the ink recovered sooner to the high viscosity after the shear was released and was suitable for printing. The ink was also printed on coated paper. Fastness was up to 91% and scratch resistance achieved H. The print effect on black cardboard and PET film was also excellent. The prepared edible ink provides a novel alternative to traditional ink and holds great potential in printing industry, especially on food.

We have developed a new method for characterizing paper coating structure using FIB milling technique and FE-SEM. A new image analysis method combining smart blur and locally adaptive thresholding technique was applied. Compared to conventional method, this method preserved the edge of target and gave better automatic image segmentation of pores. We applied this method for the measurement of the pore structure in pigment coating layers. Staining with OsO4 and resin-embedding treatments were used for the sample preparation of coated papers for image analysis. A control sample without any treatment was also used in analysis. BSE images of osmium stained and resin-embedded coated paper gave the clearest image segmentation of coating components. The results showed that three sample preparation methods gave similar z-directional porosities. Lower porosity and smaller pore size was obtained from the top surface layer with the osmium stained and resin embedded samples.

The objective of this paper was evaluate the effects of spray time, nanoclay content and corona discharge on oxygen transmission rate (OTR), water vapor transmission rate (WVTR), basis weight, thickness and tensile strength of the coated papers. An aqueous slurry base, a mixture of cellulose nanofibrils (CNF) and nanoclay particles, was sprayed on a kraft writing & printing paper surface as base substrate. Upon drying, the suspension on the paper surface formed a hybrid nanocomposite layer with CNF (matrix) and nanoclay (mineral filler). Paper substrate was coated by a laboratory-assembled spray coater. Corona discharge enhanced the wetting of paper surfaces, improving adherence between paper and hybrid composite. Increased spray time improved tensile strength and barrier properties i.e. OTR and WVTR. Higher nanoclay content in coated paper enhanced its barrier properties but reduced its tensile strength. Tensile strength and morphological properties demonstrated effective adhesion between base substrate and hybrid composite.

Chitosan is a biodegradable natural polymer, coated on the surface of the paper can improve the oxygen barrier properties and resistance to fluid permeability of ordinary packaging paper, but the influence on resisting to water permeation are not enough. In this paper, through the analysis of the infrared spectra, surface properties, elongation, water resistance and water vapor barrier properties of the coated paper, the effects of glycerol plasticizer on the chitosan-coated paper were studied. The results showed that the addition of glycerol could increase the softness of chitosan. When the content of glycerol was 20 wt%, the elongation of the chitosan-glycerol coated paper increased 25.2% to the uncoated paper and 7.4% to the chitosan-coated paper. Meanwhile, those chitosan-glycerol-coated paper had better effect on resisting to water permeation, although the water vapor barrier properties could be improved.

It is very important to improve the situation that paper mulching film is easily affected by rain and hot air aging in the field. In this paper, stearic acid and polydimethylsiloxane (PDMS) were used to modify zinc oxide (ZnO) and silicon dioxide (SiO2) to obtain particles with lower surface energy. Then, the modified ZnO and SiO2 dispersion were brushed on the surface of paper mulch film by nylon brush, and the superhydrophobic paper mulch film was successfully prepared. The changes of hydrophobicity and mechanical properties of paper mulching film before and after dry heat aging were verified by contact angle and rolling angle test, acid-base salt test, self-cleaning test and mechanical test. The surface roughness, three-dimensional morphology and scanning electron microscopy were used to characterize and analyze. The test results show that the prepared paper mulch film not only has extraordinary superhydrophobic performance, acid and alkali resistance, self-cleaning performance, but also can effectively improve the mechanical properties of paper film in dry and hot environment. The research content of this paper provides technical guidance for developing high-performance paper mulch film.

Imparting electro-conductivity to cellulosic paper may allow this conventional material to hold great promise for a wide range of applications. In this work, polyaniline/cellulose nanocrystal (PANI/CNC) composite was prepared via emulsion polymerization and subsequently used as a conductive and reinforcing pigment for paper coating fabrication. Initially, the microstructure and properties of the fabricated PANI/CNC composite were comprehensively characterized. Furthermore, the effect of the PANI/CNC composite on the properties of paper coatings and coated paper was systematically investigated. The results showed that the viscosity and viscoelasticity of paper coatings were increased as a function of the PANI/CNC composite addition. Meanwhile, the increased CNC ratio in PANI/CNC composite led to the decreased viscosity and viscoelasticity of paper coatings. Furthermore, surface coating application was found to impart desired electro-conductivity and enhanced mechanical properties to coated paper. Compared to the coated paper without PANI/CNC composite, the coated paper with 4 wt% CNC added PANI/CNC composite maintained an electro-conductivity of 4.0 S·m−1 and exhibited increases of 14.6%, 30.7% in tensile index and folding strength, respectively. In particular, the electro-conductivity and mechanical properties of coated paper were also enhanced with the increased ratio of CNC in PANI/CNC composite.

It is a challenge to fabricate low-cost and flexible electronic devices with degradable materials. In this work, a flexible and degradable strain sensor was fabricated on paper substrate by dip-coating in an aqueous suspension of carbon black (CB) and carboxymethyl cellulose (CMC). The composition of CB and CMC in the suspension was firstly studied for producing a uniform conducting layer on the paper. Then the strain sensor was obtained by assembling the coated paper and wires with silver paste. The sensor exhibits gauge factor of 4.3 and responsive time of approximately 240 ms, demonstrating the capability of monitoring various human motions with high stability >1000 cycles. The micro-gaps between CB particles and cracks on the surface of the CB layer can account for this resistive-type sensitivity. The degradation test shows that the sensor can be degraded soon under gentle rubbing in wet state, implying it is an environment-friendly “green” electronic device. Furthermore, the cost of the sensor is qui...

This paper prepared 4 inks mainly based on chitosan with different molecular weight and different mass percentage, and pigment (FeO(OH)·xH2O). The inks were characterized using Fourier transform infrared spectroscopy (FT-IR). Rheological properties were discussed by shear rate, time, temperature, oscillatory modulus, yield stress, and screen-printing simulation. Antimicrobial activity was analyzed by the growth inhibition zone. The inks were also applied to screen printing on substrates containing coated paper, nori, chocolate, etc. The print performance of the inks on coated paper was investigated by contact angle, optical density, print fastness and scratch resistance. 4 inks possessed obvious thixotropy and different linear viscoelastic regions. The experimental yield stress was 39 Pa and viscosity recovery rate was up to 76% after 105 s. Growth inhibition zone achieved 12.0 mm in diameter and optical density reached 1.2 with contact angle being 73°. The results indicate that the developed ink is applicable for screen printing.

Starch and poly(vinyl alcohol) based barrier coatings for flexible packaging papers were studied. Both octenyl succinate modified and hydroxypropylated corn and potato starches were blended with regular and ethylene modified poly(vinyl alcohol) to increase the water vapor barrier properties and enhance the flexibility of the starch coatings, in order to accomplish superior barrier performance. Phase separation between starch and poly(vinyl alcohol) was studied in detail, both in the solution and in dry draw-down coatings on paper. The barrier performance of the coated paper was evaluated with respect to water vapor transmission rate. Conditions for the creation of a thin surface layer consisting of only one of the pure polymers were identified and discussed in terms of phase separation in solution migration of poly(vinyl alcohol) to the uppermost surface layer. The phase separation promoted low water vapor transmission rates also with a rather high fraction of starch in the coatings.

Two functionalized xylans, namely a carboxymethyl xylan (CMX) and a 2-dodecenyl succinic anhydride-modified xylan (X-2-DSA) were, i) synthesized from beechwood xylan (BX) and characterized for their structural properties, thermal behaviour and molar mass and, ii) used in the production of paper/xylan laminates for food packaging. Films prepared from the functionalized xylans by solvent casting were applied onto paper employing the calendering moulding under pre-selected conditions in order to produce the laminates. The obtained laminates, as well as the starting base paper and the xylan-derived films, were characterized for their mechanical and barrier properties. The novel type of laminates demonstrated a synergistic effect with respect to its individual constituents, as the Young's modulus, tensile, tear and burst strengths of laminates were significantly improved in comparison to those of the starting paper or the xylan films. The xylan-coated paper laminates showed good moisture barrier properties, reducing up to 30-fold the water vapor permeability of the paper. At the same time, despite of fairly good oxygen barrier properties of the bio-based films from functionalized xylan, their application in paper laminates did not permit maintaining the same order of magnitude of oxygen transfer rates, which were, however, comparable to those reported for packaging papers coated by polyethylene films.

Starch-coated paper is widely used in packaging, printing, writing, and so on. However, achieving starch-coated paper with excellent moisture resistance remains a challenge for its end uses. To overcome this challenge, we hypothesize that the film-forming ability of starch plays a pivotal role in the moisture resistance of starch-coated paper. Polyvinyl alcohol (PVA) is used to enhance the film-forming capability of starch film and the moisture resistance of PVA/CS coated paper is evaluated in terms of moisture absorption, tensile index, and stiffness. A PVA/CS film with only a coating weight of 4.0 g/m2 can fully cover the porous structure of paper that leads to a higher moisture resistance than CS-coated paper with a similar loading weight. However, as the coating weight continues to increase, the decline of the mechanical properties of PVA/CS coated paper is almost unchanged. Furthermore, the moisture resistance of PVA/CS coated paper (coating weight is larger than 4.0 g/m2) is further improved by using glyoxal as moisture proof agent (MPA). Only 4.8% and 6.3% losses in the tensile index and stiffness at a coating weight of 4.0 g/m2 are achieved before and after moisture treatment, respectively. These results may shed light on exploring new method to enhance moisture resistance of starch-coated paper.

In this work, we investigate the role of zinc oxide nanoparticles in the inherent protection of paper works against damaging effects of ultraviolet radiation, pollutant gasses, mold, and bacteria. For this purpose, the cellulosic nanocomposite of ZnO was used as protective coating on the surface of the paper. This nanocomposite can act as a consolidant as well. To determine the protective potential of this coating, the chemical and physical properties of treated papers after light and heat accelerated aging were measured. Results showed good stability of papers with nanocomposite coating. Also, a good light stability was shown in the colored paper that was treated with this nanocomposite. Furthermore, to demonstrate the degree of antifungal and antibacterial properties of coated papers, sample papers were treated with two common fungi and bacteria, and the positive preventive effect of coated paper against fungi and bacteria was observed.

In the present work, raw paper sheets were coated with biopolymeric solutions based on gelatin crosslinked with transglutaminase enzyme, containing glycerol as plasticizer, and citric acid as antimicrobial and antioxidant agent, for packaging beef. Thickness, grammage and bulk density analysis have shown the effectiveness in forming the coating film, which was confirmed by morphological analysis. The biopolymeric coating did not show improvement in mechanical properties, but the water vapor permeability was significantly reduced while maintaining the original optical properties of the paper sheets. The beef packaged in the active papers shown a lower microbial population at the end of the four days of storage, and had greater stability to lipid oxidation during the entire period. The active papers sheets held the desirable red color and significantly lower pH values ​​compared with beef packaged in the uncoated control paper. The coated papers sheets still acted positively to prevent the loss of moisture from the beef to the environment.

In the research, kraft paper was coated with a blend of chitosan and rice starch ultrasonic-treated coating solution. The novelty in this paper is the use of bio-based coating solution which was treated with ultrasound, which led to a positive effect on the mechanical, optical and water barrier properties. The goal of the research was to improve the coating solution with ultrasound and to make the coated kraft paper with chitosan and rice starch suitable for a packaging material. To evaluate the influence of the ultrasonic treatment on coating solutions, the moisture content, water vapour permeability, absorptiveness, tensile strength, elongation at break, tear and bursting strength, colour values, gloss and surface properties of coated paper were determined. The research showed that the moisture content in all coated papers decreased by less than 0.5%, the water vapour permeability reduction being around 20%. Tensile strength, elongation at break and tear strength improved at coated paper, even more at the one pretreated with ultrasound. Bursting strength, which is important at paper bags, increased by 9% at coated, and by 12% at coated and ultrasound-treated paper. Furthermore, gloss improved at both coated papers. As expected, the coating affected the surface, with fewer and smaller pores. At paper the coating of which was treated with ultrasound the surface was smoother and fewer pores were detected. The results showed that the ultrasonic treatment is not only an inexpensive and environmentally friendly process, but is also very effective in the preparation of solutions for bio-based coatings. Such coatings have better moisture resistance and are more flexible, which is important for packaging paper. Therefore, preparing solutions using ultrasound as pretreatment is an improved and convenient procedure to enhance many properties of bio-based coatings.

A water-based environmentally friendly electrically conducting ink composed of cellulose nanocrystals (CNC) and polyaniline (PANI) was prepared. PANI was synthesized by the emulsion polymerization approach using dodecylbenzenesulfonic acid (DBSA) as the dopant to induce spherical nanoparticulate formation. Glycerol was used to adjust the viscosity of the ink. The CNC–PANI ink was characterized by transmission electron microscopy, UV-visible spectroscopy and viscosity measurements. The ink was successfully printed on multilayer curtain coated paper by the flexographical printing method. The printed layers were characterized by optical and atomic force microscopy techniques and cyclic voltammetry. A stable nanoparticulate CNC–PANI ink with an electrical conductivity of the printed films between 30 and 60 S cm−1 was obtained which was more than an order of magnitude higher than for the corresponding film without CNC.

Some drawbacks such as lack of durability, requirement for high-cost fluorosilane modification, and complicated fabrication processes have limited the practical applications of superhydrophobic coatings for several years. In this work, we provide a novel method to fabricate a robust superhydrophobic coating without pre-modification by pressing ZnSn(OH)6 (ZHS) particles into polydimethylsiloxane (PDMS) solution, and then curing. PDMS used in this work is not only a low surface energy material, but also an adhesive to enhance the bonding force between particles and substrates. The PDMS@ZHS coating (ZHS particles coated on PDMS) is also superhydrophobic when it is immersed into dodecane, and shows excellent self-cleaning in air and oil environments. After undergoing serious chemical corrosion and mechanical abrasion, the superhydrophobicity of the coating remained well. For different kinds of substrates, this coating can be covered and repels water as well. Owing to the excellent flame-retardancy of ZHS particles, PDMS@ZHS coated paper displays excellent flame retardancy in limiting oxygen index (LOI), vertical flame, and cone calorimeter tests. We believe that this simple, environmentally friendly, and versatile fabrication of the PDMS@ZHS coating has excellent real-life applications.