Ink Absorption Research Articles

Research on Ink Absorption Effect of Adhesive on Foam Plastic Surface Coatings

The purpose of this paper is to study the influence of different adhesives and dosage on the performance of ink absorption coating and improve the quality of foam surface. In this experiment, silica was used as pigment, PVA1788, PVA1799, PVA235 and soluble starch were used as binders, and rigid polyurethane foam was used as coating object. In this experiment, a spraying method was used to coat the surface of plastic foam, UV printer was used for graphic output, and related equipment were used to test the performance of the coating. The results showed that when the ratio of adhesive (PVA1788) to pigment was 20%, the whiteness and wettability of the coating were the best. In this case, rich color range and gradation level could be obtained. With the increase of the alcoholysis of polyvinyl alcohol, the dissolution became difficult, water resistance increased, bonding force increased, film formation became better, and the contact angle of the coating prepared by the high alcoholysis of PVA as adhesive was lower. The coating with PVA235 as adhesive had the highest color density and the best comprehensive effect.

Optical properties in the visible range of two different India ink used as biological phantoms

The optical characteristics of two different brands of India ink, Parker Quink and Pelikan, as an absorber used in preparation a tissue-simulating phantom, have been investigated at visible wavelength range. For this purpose, a single integrating sphere system and a spectrophotometric transmission spectroscopy have been used to estimate the radiometric characteristics. Then, inverse adding-doubling algorithm was implemented to retrieve the optical coefficients of pure ink samples. Parker ink's absorption behavior turned out to incompatible with Pelikan over the present wavelength range. Furthermore, scattering property of both two brands has been exhibited and the albedo was calculated. Parker albedo showed a decremental behavior with wavelength and varied between 0.381 and 0.13. A structural profile of albedo was found for Pelikan, which varied between 0.366 and 0.03. This discrepancy might be explained by the variety of two brands composition besides experimental errors. Furthermore, Parker ink absorption variation turned out to be in correspondence to several tissues' absorption feature over broad wavelength ranges. Finally, Parker ink could be regarded as a better candidate to mimic absorption property for several tissues.

Wheat/faba bean intercropping improves physiological and structural resistance of faba bean to fusaric acid stress

AbstractFusarium oxysporum f. sp. fabae is the causal agent of fusarium wilt. Fusaric acid (FA), produced by F. oxysporum, plays an important role in the occurrence of disease, and intercropping is an effective measure for control of disease and for improving host resistance in plants. The objective of this study was to investigate the physiological and biochemical responses, and mechanisms of tissue structure resistance, of intercropped faba beans following exposure to different concentrations of FA. Results demonstrated that intercropping reduced the occurrence of fusarium wilt, and improved faba bean growth and yield. In addition, wheat intercropping significantly reduced red ink absorption of faba bean (33.2%), increased water content (3.1%), and increased activity of the root antioxidant enzymes peroxidase (POD) and catalase (CAT) (26.3% and 2.2.%, respectively). Furthermore, increased lignin content and callose deposition in plant vessels were observed (12.5% and 42.7%, respectively) when subjected to the highest concentration of FA stress (200 mg/L). Intercropping resulted in more intact root cell morphology, increased occurrence of intracellular vacuoles, increased cell wall thickness, and an increase in the number of mitochondria and rough endoplasmic reticulum. Intercropping alleviated the wilting effect of FA on faba bean via enhanced physiological, biochemical, and tissue structure resistance of faba bean root.

Effect of PCC crystallization and morphology on flocculation with microfibrillated cellulose, on sheet densification and liquid absorption behavior

Composite sheets consisting of elongated and aggregated cationically charged precipitated calcium carbonate (PCC) and native microfibrillated cellulose (MFC) were prepared with a wet laying method. The furnishes were prepared with and without an anionic flocculating agent (polyacrylamide) in order to adjust the structure of the sheet. The samples were compressed (densified) in order to determine the particle and microfibrillated cellulose-PCC structure coalescence and densification, as well as its subsequent influence on liquid absorption behavior. The densification affected both the vertical and lateral distribution of PCC, but the flocculating agent enhanced the compression stability and stabilized the sheets against PCC material flow. The differences between the sheets made with and without the flocculation aid affected the absorption of an anionic dye-based fluid ink, which was evident as a higher print density and less print bleeding. The absorption behavior was dependent on the sheet structure, especially on the PCC distribution within the sheets. Finally, the role of MFC on floc structure and floc formation is discussed.Graphic abstract

STUDY ON THE GRINDING TIME DURATION IMPACT ON THE PROPERTIES OF PAPER FROM ALTERNATIVE RAW MATERIALS

Both raw and recycled fiber materials are used for paper production. The increase in percentage use of the latter is due to their paper-forming properties, availability and low cost. The article explores the possibility of using pulp from the inner layer of mulberry twig bark. Mulberry twigs, after removing leaves, which are the main raw material in silk production, have no practical industrial application. Recycling waste - mulberry branches - for the production of pulp is therefore relevant as it is aimed at solving raw material and environmental problems. The purpose of this work is to use local raw materials for paper production, study the impact of processing method of the grinding process on paper forming properties. During grinding the mechanical processes of changes of fibers determine mainly structure of a paper sheet, and colloidal-physical processes - bind and ability of fibers to form strong, homogenous and smooth structure of paper. The structure of the sheet of paper facilitates excessive or "selective" ink absorption into the pores of the paper and thus predetermines the quality of reproduction during the printing process. Methods for determining the physical and mechanical properties of papers were used in this work, and changes in the surface structure of samples cast at various technological modes of the milling process were studied. The results of the study revealed that the addition of cellulose mass from the inner layer of mulberry twig bark helps to obtain a strong paper. The optical properties of the paper, which contains cotton and cellulose from the inner layer of mulberry branch bark, are explained by the whiteness of the added fibers themselves. The strength properties of the paper at a weight grinding degree of 300 CWR are explained by the bond between the split and strongly interwoven fibers of the cellulose fibers. It has been established that the addition of more than 30% cellulose from the inner layer of the mulberry branch bark to the paper pulp mass is undesirable, as this adversely affects the whiteness of the paper

Preparation and characterization of CaCO3 filler modified with double-site stearic acid for trademark fabric coated by polyamide

A novel trademark fabric coating filler was prepared by modifying CaCO3 with double-site stearic acid, and the double-site stearic acid modified CaCO3 filler was applied in polyamide coating to achieve a trademark fabric with excellent printing effect and environment friendly. The double-site stearic acid and modified CaCO3 was characterized by Fourier transform infrared (FT-IR), 1H-NMR spectrum, mass spectra, scanning electron microscope (SEM) and thermogravimetry (TG). The modified CaCO3 was used to prepare the polyamide coated film and trademark fabric. The results showed that the double-site stearic acid was successfully synthesized and then were encapsulated to the surfaces of CaCO3 particles, and the lipophilic and dispersibility of CaCO3 were improved. The modified CaCO3 with 15 wt% double-site stearic acid could obtain a good activation degree and dispersion stability. The application properties of the polyamide coated film and trademark fabrics using modified CaCO3 were further studied. When the concentration of double-site stearic acid was 15 wt%, the strain and stress of polyamide coated film could be improved 50.06% and 37.04%, respectively. And the trademark fabric displayed the best ink absorption, the pH value of trademark fabric was decreased 0.9 compared to unmodified CaCO3.

Effect of the primer on barcode quality in ink-jet printing

It has been proposed to modify the surface of offset and coated paper with a special coating (primer) that ensures the high quality of ink-jet printing, specifically barcodes. The application of digital ink-jet printing using aqueous-based inks makes it difficult to achieve the required print quality on conventional paper. Ink-jet printing is widely used in the production of customized packaging and labeling products. Given that this type of products contains the printed barcode, it is necessary to ensure its functionality (readability) after printing.The primer ensures a controlled process of ink absorption at ink-jet printing, thereby improving the print quality. To this end, a composition of the primer was used on the basis of a water solution of the interpolymeric complex of polyvinyl alcohol (PVOH) and polyvinylpyrrolidone (PVP).The influence of the primer that contains different amounts of the interpolymeric complex on a change in the water contact angle of imprinted paper has been investigated.Prints on paper with and without the primer were obtained using an ink-jet printing method; quality of the line and barcode print was assessed. Such quality indicators for the line were defined as a line width on the imprint, a line blurriness at the line-paper interface, a line raggedness, and the optical density. In addition, the primer's effect on the barcode print quality at ink-jet printing was investigated.The study results make it possible to ensure the high quality of barcode printing on conventional print papers by using an ink-jet printing method. Applying the primer improves the line and barcode print quality. The barcode quality grade increases from the lowest (unacceptable) score of 0 (F) on paper without a primer to a score of 2 (C) on paper with the primer, which warrants that it is readable on packaging by a scanner.

Nanocrystalline Cellulose and Polyvinyl Alcohol Coating Application to Cardboard Packaging Papers and Investigation of the Effects on Paper Properties

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.

Effect of papermaking conditions on the ink absorption and overprint accuracy of paper

The ink-absorption capacity is an important factor for evaluating the printing quality of paper. In this study, the effects of different parameters of papermaking on the ink-absorption capacity of paper were investigated. The results showed that hardwood pulp exhibited better performance in increasing the absorptivity of paper compared with softwood pulp. When the content of hardwood pulp in paper was increased from 0% to 100%, the ink mark length decreased from 5.1 cm to 4.3 cm. Furthermore, a basis weight change from 100 g/m2 to 60 g/m2 increased the ink-absorption capacity, as revealed by a decrease of the ink mark length from 4.8 cm to 4.4 cm. Both sizing agent and beating degree affected the ink-absorption performance of the paper. For example, a shorter ink mark length of 5.1 cm was obtained at a low beating degree of 5000 r compared with that of 5.1 cm at 15000 r.

Enhanced ink-absorption performance of inkjet printing paper-based patterns with core-shell-structure CaCO3{\mathrm{CaCO}_{3}}@SiO2{\mathrm{SiO}_{2}} pigments

Abstract The inorganic core-shell pigment CaCO 3 {\mathrm{CaCO}_{3}} @ SiO 2 {\mathrm{SiO}_{2}} was synthesized using a sol-gel method, and the pigment was applied as a surface coating on inkjet paper to study the influence of inorganic core-shell pigments on the dynamic permeability, surface properties, optical properties and inkjet-printing performance of coated paper. CaCO 3 {\mathrm{CaCO}_{3}} @ SiO 2 {\mathrm{SiO}_{2}} prepared using carboxymethyl cellulose (CMC) had better coverage than that prepared using polystyrene sodium sulfate (PSS) dispersant. The CMC-prepared CaCO 3 {\mathrm{CaCO}_{3}} @ SiO 2 {\mathrm{SiO}_{2}} -a had improved dispersibility, and the solids content of the coating reached 35 %. Inorganic core-shell pigments improve the surface and optical properties of the coated paper, making them similar to those of a reference calcium carbonate-coated paper. The smoothness and gloss improved by 60.8 % and 78.4 %, respectively, compared with those of silica-coated paper. The inkjet solid density and dot definition increased by 28.8 % and 4.1 %, respectively, compared with those of the calcium carbonate-coated paper. Preparing inorganic core-shell pigment CaCO 3 {\mathrm{CaCO}_{3}} @ SiO 2 {\mathrm{SiO}_{2}} is an effective method to fabricate inkjet printing coatings with advantageous microstructures for ink absorption.

The effect of O2 plasma treatment and PA 6 coating on digital ink-jet printing of PET non-woven fabric

In the absence of pre-processing, polyethylene terephthalate (PET) non-woven have strong hydrophobicity. Therefore, patterns printed with pigment ink-jet printing have poor color yield and low resolution. In this study, the surface properties of PET non-woven fabric were modified by plasma treatment, and a coating solution made by waste polyamide 6 (PA 6) filament, methanol, and CaCl2 to prepare 3.5% and 6.8% PA 6 concentration. After that, plasma-treated sample, coated sample, and plasma treatment plus PA 6 coated sample results on pigment ink-jet printing were investigated to prepare good printing PET non-woven packaging fabric. Scanning electron microscopic image indicated that plasma makes etching on the fabric surface, hence increase the hydrophilic property of the fabric, which helps slight increase in the color yield and resolution. The contact angle shows PA 6 coating also achieved hydrophilic on the surface of PET non-woven fabric and facilitated the ink absorption in pigment ink-jet printing, which helped the printed fabric have higher color yield and clear resolution. However, for significant results it was very important to increase the absorption of coating solution. Plasma makes it easier for the fabric to absorb more coating solution containing dissolved waste PA 6 filament in both concentrations from 11.97% to 19.92% and 5.68% to 10.50%. This ultimately provides the capacities for the fabric to capture more ink and penetration of more colorant particles into the fabric. Therefore, plasma treatment first plus PA 6 coating can help prepare better-patterned PET non-woven fabric packing through pigment ink-jet printing, even though the plasma treatment and coating caused a little negative influence in whiteness and handle.

Citric Acid Modified Kaolin and Its Application in Polyamide Wet Coating

The ink absorption of polyamide-coated polyamide textile products containing kaolin is poor. Citric acid was used to modify kaolin, and the adsorptive performance of rhodamine B was studied. The modified kaolin with the best adsorptive ability was selected. The results showed that kaolin modified with a 2.0 M citric acid solution was strongly adsorptive. During the interaction between citric acid and kaolin, H+ acts on the surface and interlayer of kaolin, and on Al3+ and Si4+ in the kaolin. This results in an increase in the specific surface area and a smaller particle size. After using modified kaolin in the polyamide wet coating, the ink-absorption of polyamide-coated polyamide fabrics improved and the resulting pH value met Oeko-Tex Standard 100 requirements for textile use.

Effects of the Coating Mixture on the Penetration of Liquids into Paper

The pigment coating of paper is usually performed to enhance the physical properties of paper and its printability. The coating generally makes paper whiter, brighter and more opaque. The properties of the coated paper depend, among others, on the porous structure of the coating developed, which is determined by the pigments, binders and their reactions. The influence of the type and quantity of coating components and ink absorption into the coating layer was studied in this work. Printing ink penetration was measured using a Penetration Dynamic Analyser with an HVL module (High Viscous Liquid). The evenness of liquid penetration into paper was measured using a Penetration Dynamic Analyser with a PEA module (Print Evenness Analyser). Results obtained indicate that all three variables – coating pigment type, latex dose and ink type – may have an equally strong influence on liquid and ink penetration,and thus on print quality.

Citrus-based hydrocolloids: A water retention aid and rheology modifier for paper coatings

The rheological and dewatering behavior of an aqueous pigmented coating system not only affects the machine runnability but also affects the product quality. The current study describes the use of natural hydrocolloids derived from citrus peel fibers as a rheology modifier in paper coating applications. The results were compared with carboxymethyl cellulose (CMC) in a typical paper coating system. Water retention of the coating formulation was increased by 56% with citrus peel fibers compared to a default coating, and it also was higher than a CMCcontaining coating. The Brookfield viscosity of paper coatings was found to increase with citrus peel fibers. Compared to CMC, different citrus peel fibers containing coating recipes were able to achieve similar or higher water retention values, with no change or a slight increase in viscosity. Coatings were applied on linerboard using the Mayer rod-coating method, and all basic properties of paper were measured to assess the impact of citrus peel fiber on the functional value of the coatings. Paper properties were improved with coated paper containing citrus peel fibers, including brightness, porosity, smoothness, surface bonding strength, and ink absorption.

Digital decoration for ceramic tiles: The effect of glazes particle size distribution on the inkjet decoration

After the consolidation of the digital decoration technology in the ceramic tile industry, digital glazing is the next step toward a fully digital decoration line. To make this possible, a key requirement, regarding glaze suspensions characteristics, is the reduction of the actual particle size of the solids. In this context, the objective of this work is to evaluate the effect of the particle size distribution of frits used to produce a transparent glaze on the glaze layer characteristics and the ink behavior over the same. A frit was milled under different conditions. The milling process has mainly reduced the size of the larger particles, leading to narrower particle size distributions. As the distribution curves narrowed, the particles packing efficiency in the glaze layer decreased. For these more porous layers, faster ink absorption into the surface pores and a consequent more limited ink spreading were observed, which leaded to the production of smaller dots. Thus, changes in granulometry of the glaze raw materials affected not only the glaze layer porous structure, but also aspects of the image quality.

Edible solid foams as porous substrates for inkjet-printable pharmaceuticals

The aim of this study was to investigate new porous flexible substrates, i.e., solid foams that would serve as a carrier with a high ink absorption potential for inkjet printable pharmaceuticals. Propranolol hydrochloride was used as a model active pharmaceutical ingredient (API). Pharmaceutically approved and edible cellulose derivatives and gums together with different additives were evaluated as a base for the substrate. Different methods for preparation of a solid foam such as freeze-drying, vacuum oven drying and drying at room temperature were explored. Only freeze-drying of the polymeric solutions resulted in the desired porous and flexible, but mechanically stable, soft sponge-like substrates with hydroxypropyl methylcellulose (HPMC)-based solid foams being the most suitable for the use in continuous inkjet printing. The plasticized HPMC foams had a superior absorption capacity and fast penetration speed for the different solvents due to the open cell pore structure and higher porosity as compared to nonplasticized additive-free foams, although, the latter were less hygroscopic. The produced solid foams were well suited for inkjet printing of high volumes of API-containing ink. The inkjet-printed API was immediately released from the dosage forms upon contact with the dissolution medium. This work demonstrates that the fabricated solid foams, based on plasticized HPMC, show a great potential as porous carriers in the fabrication of high dose dosage forms by inkjet printing.

Study on color ink-jet printing paper coating with nano-SiO2 as pigment

With many years of research, color ink-jet printing technology has reached the requirements of color ink-jet printing. The significance of this experiment is to find a suitable method to improve the quality of color ink-jet printing paper. In this work, the dispersion effect and types of sodium polyacrylate (PAAS) on nano-SiO2 solution are discussed, and the most suitable PAAS dosage is selected. When the dosage of PAAS is 8%, the dispersibility of nano-SiO2 solution is much better, with an average color density of 1.60, a gloss of 59% and an ink absorption value of 10.2 cm. Adhesives also have a great influence on color ink-jet printing paper. When the amount of PVA is 30% of nano-SiO2, the average color density is 1.62. Glossiness and ink absorption are also the best.

Effect of core-shell structure latex on pigment coating properties

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.

Thermochromic ink–paper interactions and their role in biodegradation of UV curable prints

In this study, biodegradability aspects of UV thermochromic leuco dye print on three different paper materials (synthetic, recycled, and bulky) were studied using the soil burial test under anaerobic conditions. Biodegradation of UV curable thermochromic prints were evaluated for changes by visual examination, microbial growth assay, weight loss measurements, Fourier transform infrared spectroscopy, scanning electron microscopy and colorimetric measurements. Results showed a better absorption of ink into the bulky paper structure, followed by recycled paper. Synthetic paper is not absorbent. The ink binder altogether with classic pigment and microcapsules penetrates into the structure of bulky paper. Recycled paper absorbs ink binder mostly with classic pigment. Better adsorption of binder into the bulky paper structure results in thinner layer of ink binder on the paper surface. On non-absorbent synthetic paper, microcapsules are covered with thicker layer of ink binder. In the case of bulky paper, the highest rate of biodegradation was observed, resulting in a higher number of bacteria, higher weight loss, higher changes in colour (destruction of almost all microcapsules) and almost complete reduction in thermochromic effect of the prints. Results show that microcapsules, which penetrate into the structure of bulky paper, are promoting the rate of bulky paper biodegradation. The opposite behaviour was noticed for the penetration of classic pigment into the structure of recycled paper, which resulted in remarkable reduction of recycled paper biodegradation rate. The thicker layer of ink binder (containing classic pigment) on the surface of microcapsules on recycled paper resulted in slower rate of microcapsules degradation and smaller colour change of the print. The thickest layer of ink binder and classic pigment on synthetic paper surface causes the slowest rate of biodegradation of print.

The effect of anionic-cationic multilayering and microstructure on dye-based ink absorption

The effect of water-soluble anionic binders and a modified cationic-precipitated calcium carbonate layer-by-layer structure on dye ink spreading and absorption has been studied. The multilayered coating was alternately spray-coated onto the substrate in order to determine dye interdiffusion and specific interaction including solvent absorption behavior in the nano- and microporous layers. The amount of the hydrophilic binder in the top coating was varied in order to adjust the porosity and to determine the effect of electrostatic charge interaction and to adjust dye fixation. Cationic nano- and microporous coatings and particle assemblies were created by spray-coating with cationic calcium carbonate precipitated in the presence of PDADMAC. The deposition of dye on the various coatings revealed that a small amount of anionic binder in the top coating favoured the absorption and spreading of dye and solvent, whereas a higher binder dose closed the pores and reduced the dye fixation and rate of solvent absorption. Although the top layer is essential for dye retention, it was demonstrated that the multilayering is essential not only for dye setting and dye capturing mechanism but can be utilized for vertically controlling the dye penetration and retention in the formed hydrophilic gel complex, which has a significant influence on optical effects and mechanical durability.