Inkjet Ink Research Articles

Enhanced color density from high-viscosity inkjet inks

AbstractInkjet printing inks are typically limited to low viscosities, employing highly dilute inks with low pigment loading compared with inks for other printing processes. This reduces color intensity, limits productivity, and requires higher drying energy. This study compares standard-viscosity graphic inkjet inks (~13 mPa.s shear viscosity) with higher-viscosity inkjet inks (~60 mPa.s), traditionally considered outside the normal jetting range, for print outcomes on corrugated cardboard with both white coated and brown uncoated liners. Higher-viscosity inks imparted greater color density to the print; this was assessed as being due to both the inherently higher viscosity of the ink reducing penetration into the substrate and the higher pigment loading capable of being contained within these inks. While standard-viscosity inks tended to plateau in color intensity as ink coverage was increased, higher-viscosity inks could increase in intensity throughout the entire coverage range on coated white liner. This effect was dependent on the substrate, with the coated white liner exhibiting up to a 67% increase in maximum color density but the uncoated brown liner showing up to a 13% increase. It is envisaged that wider adoption of higher-viscosity inks can increase both color intensity and printing speed, thus making inkjet more competitive with conventional printing processes.

1, 3, 6, 8-pyrene sulfonic acid tetrasodium fluorescent pigment synthesis and security ink production

Colorants used in security inks are special pigments that radiate in the UV region or IR region. Obtained pigments can be from valuable rare earth elements or they can be organic based. Organic-based pigments are generally insoluble in water, which limits their use. For this purpose, an organic-based UV-radiating pigment was synthesized and made water-soluble by forming its salt. With the obtained salt-formed pigment, inkjet ink that can be used in counterfeiting was applied and its printability and resistance properties were determined. In this study, 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was synthesized and water-based inkjet inks with hydroxy ethyl cellulose binder were produced. The prepared inks were printed on the paper surface. The color and gloss of the prints obtained were measured both in the visible region and in the UV region. Its optical properties were detected by UV spectroscopy. Strength properties such as light fastness, nitro resistance, alkali resistance, acid resistance, rub resistance, drying time, adhesion and dry film weight of the prints were determined. As a result; Inkjet ink with 1, 3, 6, 8-pyrene sulfonic acid tetrasodium salt was produced and it was concluded that it has good resistance properties.

Compatibility and performance study of electrohydrodynamic printing using zinc oxide inkjet ink

The demand for modern electronics and semiconductors has increased throughout the years, which has enabled the innovation and exploration of solution-processed deposition. Solution-based processes have gained a lot of interest due to the low-cost fabrication and the large fabrication areas without the need for high-vacuum equipment. In this study, we utilized the ZnO ink for inkjet printer ink to fabricate a thin film via Electrohydrodynamic printing. Three different ink solutions were prepared for experimentation. The EHD printing technique demonstrated the ink’s compatibility with and without the modifications. The outcomes of the EHD printed materials were comparable with the spin-coated thin films. The EHD-printed films demonstrated better results in comparison to spin-coated films. Ra and Rq of the EHD film measured at 3.651 nm and 4.973 nm, respectively. It improved the absorbance up to two-fold at 360 nm wavelength and electrical conductivity up to 40% compared to the spin-coated films. Furthermore, the optimization of the printing parameters can lead to the improved morphology and thickness of the EHD thin films.

Innovative ceramic pigments from recycled lithium-ion battery cathodes for inkjet applications

The booming of the electric mobility together with the need of storing renewable energies have increased the demand of lithium-ion batteries which will bring about increasing amounts of electronic waste. Besides, the need for alternative sources of certain raw materials considered critical has changed the perception of determined wastes, which are no longer considered residues but sources of raw materials. In this work, the active cathode material present in end-of-life lithium-ion batteries (Ni, Co, and Mn) was used as secondary raw material, after being properly separated, in the synthesis of a cobalt iron nickel manganese chromium black spinel ((Co, Fe, Ni, Mn) (Fe,Cr)2O4). The pigment was used in the formulation of a ceramic inkjet ink which was deposited over a single-fired porous tile and porcelain tile. Texture and brightness of the ink were not affected by the use of this waste, thus presenting excellent prospects for the industrial ceramic application.

Black Carbon Pigment from Coconut Shell Sawit Innovation Inkjet Printing Ink for Acrylic Polymer Styrene Textile Fabric

This research proposes an innovation in the development of inkjet printing ink that uses black carbon pigment obtained from palm coconutshells. The main objective of this study was to look at thecharacterization of textile inkjet ink from the black carbon pigments of the palm coconut shell. The black carbon pigment produced from the coconut coat has been identified as the source of the pontentionalprinting ink of the textile fabric based on the polymer of acrylic styrene. The research method involves the extraction and purification of carbon pigments from palm coconut shells, as well as the formulation of inkjetprinting. The composition of the textile inkjet used in this study is that black carbon pigments come from palm coconut shells while the adhesives used are acrylic styrene, aquadest, potassium hydroxide (KOH), poly (natrium 4- styrenesulfonat). The research included the physical characteristics of the black carbon pigments produced and the evaluation of inkjet printing textiles using pigments. Textile inkjetcharacteristics. Results of ink testing using Binocular Microscope Scanbest sample CAST1. The results of ink pigment testing on wool fabrics and image analysis testing the lowest values are found on CAST1 sample. The result of the viscosity test that the ink viskosity value CAST1 of 13.1 is close to the value of commercial ink.

Wearable patterned single electrode-based triboelectric nanogenerator for peak-encoded interface

Advancement in human-machine interface (HMI) is indispensable for development of virtual/augmented reality, robotics control, and artificial intelligence (AI). However, there lack a simple facile electronics to achieve accurate finger motion recognition and remote robot control through simple signal processing. Herein, a wearable patterned single electrode-based triboelectric nanogenerator (PS-TENG) based on regenerated silk film (rSF) is developed for peak-encoded interface, which can accurately identify the handwritten numbers or letters. The patterned single electrode, composed of nine units with five different patterns, is successfully constructed by ink-jet printing Ag inks on the rSF. When handwriting on the PS-TENG, the generated output voltage with different peak amplitude can be transformed into a peak spectrum with spatial information. Handwriting numbers or letters can be accurately identified through simple digitization data processing of the peak-encoded spectrum without complex algorithms. Furthermore, the PS-TENG as peak-encoded interface enables precise game play, accurate pattern lock, and wireless robot control. Importantly, based on relative amplitude of output signals, the peak-encoded code is regardless of factors including absolute amplitude of output signals, sliding speed and environmental humidity. Consequently, the PS-TENG, characterized by self-powered feature, simple structure and straightforward signal processing, demonstrates remarkable identification accuracy of handwritten numbers and letters through decoding unique and stable peak spectrum, which would have great potential in the field of virtual control panels, HMI and AI.

Synthesis of Amphiphilic Block Copolymer and Its Application in Pigment-Based Ink.

Amphiphilic block copolymers-based aqueous color inks show great potential in the field of visual communication design. However, the conventional step-by-step chemistry employed to synthesize the amphiphilic block copolymers is intricate, with low yield and high economic and environmental costs. In this work, we present a novel method for preparing an amphiphilic AB di-block copolymer of PCL-b-PAA by employing a combined polymerization strategy that involves both cationic ring-opening polymerization (ROP) of the ε-caprolactone monomer and the reversible addition-fragmentation chain-transfer (RAFT) polymerization on the acrylic acid monomer simultaneously. The corresponding polycaprolactone (PCL) and polyacrylic acid (PAA) serve as the hydrophobic and hydrophilic units, respectively. The effectiveness of the amphiphilic AB di-block copolymer as the polymeric pigment dispersant for water-based color inks is evaluated. The amphiphilic AB di-block copolymer of PCL-b-PAA exhibits a molecular weight of 1400 g mol-1, which is consistent with the theoretical value and suitable for polymeric dispersant application. The high surface excess (Γmax) of the PCL-b-PAA in water indicates a densely packed molecular morphology at the water/air interface. Additionally, micelles can be stably formed in the aqueous PCL-b-PAA solution at very low concentrations by demonstrating a low CMC value of 10-4 wt% and a micelle dimension of approximately 30 nm. The model ink dispersion is prepared using organic dyes (Disperse Yellow 232) and the amphiphilic block copolymer of PCL-b-PAA. The dispersion demonstrates near-Newtonian behavior, which is highly favorable for the application as inkjet ink. Furthermore, the ink dispersion displays a low viscosity, making it particularly suitable for visual communication design and printing purposes. Moreover, the ink dispersion demonstrates an unimodal distribution of the particle size, with an average diameter of approximately 500 nm. It retains exceptional stability of dispersion and even conducts a thermal aging treatment at 60 °C for 5 days. This work presents a facile and efficient synthetic strategy and molecular design of AB di-block copolymer-based dispersants for dye dispersions.

DETERMINATION OF PAPER LUMEN UNIFORMITY DIFFERENT CLASSES

In this paper, a study was made of the uniformity of the clearance of office papers of various classes and
 brands. The need for a detailed study of the structure of office paper is caused by a large number of defects that occur
 during the printing process. To obtain high-quality images at high and medium speeds of equipment and at minimal
 cost, it is necessary to know the structural properties of paper and be able to control them.
 Evaluation, study and characterization of the factors that are believed to influence the interaction between
 inkjet ink and the surface of office paper can be performed using the method of expert judgment. The article describes
 an expert method for determining the gap, based on the organoleptic perception of the paper gap by a group of people.
 In the process of work, paper samples with the best lumen performance were identified. The results obtained in
 the work can be applied in the practice of printing houses for the correct choice of material for printing. This method
 of assessing the level of paper quality allows the company to quickly respond to problems associated with printing and
 further processing of printed products.

Inkjet-printed flexible piezoelectric sensor for self-powered biomedical monitoring

Printed electronics has enabled fabrication of electronic components and devices with low cost and more manufacturing and design freedom. This manufacturing technique has been successfully employed as a complementary fabrication approach to conventional nanolithography and microfabrication processes to create flexible and stretchable electronics. Fluoropolymers are crucial components in electronic devices and components, owing to their piezoelectric, triboelectric, pyroelectric, ferroelectric, and dielectric properties. In this research, we report fabrication of an inkjet-printed piezoelectric sensor based on poly (vinylidenefluoride trifluoroethylene) (PVDF-TrFE) and amine functionalized graphene oxide (AGO) for biomedical monitoring. The piezoelectric inkjet ink was obtained by optimizing the fluid mechanic properties based on Reynold and Weber numbers. The inkjet-printed freestanding film was characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), wide-angle X-Ray scattering (WAXS), and differential scanning calorimetry (DSC). The piezoelectric sensor was fabricated by deposition of silver electrodes on each side of the piezoelectric film, followed by wiring and encapsulation. The sensor was subjected to an electric field of 1500 kV/cm to align the internal dipoles and induce net polarization. The fabricated flexible piezoelectric sensor was employed for monitoring biomedical signals such as finger tapping, joint bending, and swallowing. The sensor demonstrated outstanding sensitivity of 0.1 V/kPa and excellent repeatability and stability over 1000 cycles.

Development and characterization of cinnamon essential oil incorporated active, printable and heat sealable cellulose nanofiber reinforced hydroxypropyl methylcellulose films

Cellulose nanofiber (CNF) reinforced hydroxypropyl methylcellulose (HPMC) films were incorporated with antioxidant cinnamon essential oil (CEO) to develop active, printable, and heat-sealable films. CEO was carried into the films via three types of active systems: β-cyclodextrin (β-CD) encapsulation, cellulose nanocrystal (CNC) Pickering emulsion (CNC-P), or the combination thereof (CNC-P/β-CD). The films were characterized for their mechanical, physicochemical, structural, thermal, and optical properties along with CEO release, printability, and heat seal strength. The Control film (without active CEO) and CNC-P film showed the highest transparency, 17.02% and 18.17%/mm, respectively, followed by the CNC-P/β-CD (12.86%/mm) and β-CD (11.68%/mm) films. A significant difference (P < 0.05) in water vapor permeability (WVP) was observed between the Control film stored at 33% RH (72.01 g mm/m2 d kPa) and 53% RH (54.45 g mm/m2 d kPa) whereas no difference in WVP for β-CD, CNC-P, and CNC-P/β-CD films under RH range of 33–84% (P > 0.05). The presence of active CEO in the films enhanced the moisture barrier and stability of films without influencing the mechanical and thermal properties of the films. The CEO incorporated films via both CNC Pickering emulsion and β-CD encapsulation prolonged the release of CEO. All CEO incorporated films were printable by inkjet and stamp inks and showed good heat seal strength (∼61–73 N/m). This study provided new strategies to develop cellulose-based active films with extended antioxidant function and sealable and printable properties to replace single-use plastic packaging for various food, especially high-fat food items.

Preparation &amp; Evaluation of white pigmented inkjet inks based on glycerol mono oleate - Gallic acid as a dispersing agent for textile inkjet printing

Preparation &amp; Evaluation of white pigmented inkjet inks based on glycerol mono oleate - Gallic acid as a dispersing agent for textile inkjet printing

Development of UV monomer-contained dye inks for high-quality printing application on polyester fabrics without pretreatment

The use of direct inkjet printing in the textile industry is an environmentally friendly option. However, the need for pretreatment of most fabrics before digital printing has been a major issue. In this study, a green and straightforward approach was developed that enhances printing accuracy without requiring any pretreatment. A novel waterborne disperse dye-based inkjet ink containing polyethylene glycol diacrylate (PEGDA) was developed that significantly improved the rheology of ink drops on the surface, resulting in superior printing quality on polyester fabric. The printing mechanism of the inks was thoroughly investigated by evaluating their conductivity, pH, particle size, surface tension, viscosity, and ink droplet formation. Real-time photo-rheological and low field nuclear magnetic resonance (LF-NMR) analyses were performed to investigate the behavior of the ink drops on the polyester fabric surface. Finally, the Kawabata evaluation system (KES) was employed to understand the impact of direct digital printing on fabric performance.

Polymeric Surfactants Bearing Divalent Carboxy Pendants for Stable Color Dispersions with High Redispersibility

Inkjet printing of ink requires dyes or pigments insoluble in water but uniformly dispersing as fine particles for a long period. In addition, redispersibility after solidification by solvent vaporization around the jetting heads is also important for performance. In this study, thus, a series of amphiphilic copolymers were prepared for a dispersant of inkjet using reversible addition fragmentation chain-transfer copolymerization of styrene (St), benzyl acrylate (BnA), and phenoxyethyl acrylate (PEA) as a hydrophobic monomer with acrylic acid (AA) and itaconic acid (IA) as a hydrophilic monomer. To understand the fundamental properties and potentials as a polymer dispersant, the surface parameters and rheology of the copolymers and their color dispersions in aqueous media were investigated. The aqueous solutions were typical Newtonian fluids, whereas the color dispersions were non-Newtonian fluids with shear-thinning properties and yield values ranging from 0.57 to 1.04 Pa. Although the surface parameters, such as surface tension (γ), molecular occupied area (Amin), and zeta potential (ζ), did not show clear correlation with polymer structures, their behaviors as a dispersant were significantly different. The color dispersants containing the copolymer of St or BnA as a hydrophobic monomer and IA and AMPS as hydrophilic monomers exhibited sufficient redispersion both for yellow and cyan inks, even after the aging test at 60 °C for 5 days, whereas other copolymers did not exhibit such superior performances. In addition, the color dispersions of the copolymer of St, IA, and AMPS (St-IA-AMPS) showed lower viscosity and yield value and became closer to Newtonian fluid compared with that of St, AA, and AMPS (St-AA-AMPS). Thus, St-IA-AMPS provided good redispersibility and avoided sedimentation. These results suggest that the most suitable dispersant for inkjet inks among the polymers investigated was the copolymer of St, IA, and AMPS.

Physicochemical characterization of titanium dioxide inks for digital textile printing based on newly developed polyurethane prepolymers

Purpose This paper aims to study the physical and chemical characteristics of inkjet titanium dioxide inks for cotton fabric digital printing. Design/methodology/approach Different dispersing agents through the reaction of glycerol monooleate and toluene diisocyanate were prepared and then performed by using three different polyols (succinic anhydride-modified polyethylene glycol PEG 600, EO/PO Polyether Monoamine and p-chloro aniline Polyether Monoamine), to obtain three different dispersing agents for water-based titanium dioxide inkjet inks. The prepared dispersants were characterized using FTIR to monitor the reaction progress. Then the prepared dispersants were formulated in titanium dioxide inkjet inks formulation and characterized by particle size, dynamic surface tension, transmission electron microscopy, viscosity and zeta potential against commercial dispersants. Also, the study was extended to evaluate the printed polyester by using the prepared inks according to washing and crock fastness. Findings The obtained results showed that p-chloro aniline Polyether Monoamine (J) and succinic anhydride modified polyethylene glycol PEG 600 (H) dispersants provided optimum performance as compared to commercial standards especially, particle size distribution data while EO/PO Polyether Monoamine based on dispersant was against and then failed with the wettability and dispersion stability tests. Practical implications These ink formulations could be used for printing on cotton fabric by DTG technique of printing and can be used for other types of fabrics. Originality/value The newly prepared ink formulation for digital textile printing based on synthesized polyurethane prepolymers has the potential to be promising in this type of printing inks, to prevent clogging of nozzles on the printhead and to improve the print quality on the textile fiber.

The role of resin in optimizing the performance and printing properties of water-based inkjet inks for food packaging

Purpose This study aims to investigate the influence of commercially available resins in water-based magenta pigment inkjet ink formulations on the properties of ink printability and the characteristics of ink application in food packaging. The impact of the resin on the jettability of the existing printability phase diagrams was also assessed. Design/methodology/approach Inks with different resin loadings were tested for selected properties, such as viscosity, particle size and surface tension. Stability was determined using a Turbiscan AGS turbidimeter and LumiFuge photocentrifuge analyzer. The ink layer fastness against abrasion and foodstuffs was evaluated using an Ugra device and according to PN-EN 646, respectively. JetXpert was used to assess Ricoh printhead jetting performance. Findings Printability diagrams successfully characterized the jettability of polyurethane inkjet inks on a multi-nozzle printhead and the binder improved droplet formation and printing precision. Originality/value Magenta water-based inkjet inks with commercial resins have been developed for printing on paper substrates. To the best of the authors’ knowledge, for the first time, inkjet ink stability was evaluated using the Turbiscan AGS and LumiFuge analyzers, and jettability models were verified using an industrial multi-nozzle printhead.

Development of Binder-Free Pigment Inks for Direct Inkjet Printing on Cotton Fabric without Pretreatment.

Inkjet printing technology is widely used in the textile digital printing application today though the current technology still requires pretreatment and postwashing procedures before and after printing. Additional chemical treatment generates a large amount of wastewater and complicates the process. Among the many potential approaches for reducing chemical waste, pigments with self-dispersing capability were prepared and formulated into binder-free inkjet inks that require no pretreatment or after-washing process when printing cotton fabrics. The new self-dispersing pigment inks were tested and evaluated on cotton fabrics. The distribution of particles was between 122.2 and 188.5 nm, and inks have excellent storage capability. Printed fabrics' light fastness and acid/alkali resistance are about grade 5, and printed cotton's washing and rubbing fastness are above grade 3. The mechanism and performance of ink drops were investigated by LF-NMR and ink-drop observation methods. This work provides a possible solution for reducing wastewater in the textile industry.

Visible security ink blended by Prussian blue analogues encapsulated gold (Au@PBA) nanoparticles for information hiding

Developing visible security ink with simple preparation, high optical stability and interference-free secret signals are critical to hiding security information. Here, two Prussian blue analogue encapsulated gold nanoparticles (Au@PBA NPs) with different triple-bond Raman emissions were synthesized to prepared novel red inkjet inks for security labels. And the ink formulation was well optimized to obtain suitable surface tension and viscosity. The labels contain public information in red as well as secret information that can only be acquired using Raman spectroscopy. With the visible public information on the labels, the secret information is not easy to be noticed. Also, the secret information written by the triple-bond Raman scattering is readily identifiable without interference. This method improves the security of secret information transmission, providing a new strategy for information hiding technology.

Environmentally friendly digital printing on cotton using, synthesized pigmented inkjet inks and comparison of their properties

The “top-down” approach was adopted to manufacture nano inkjet inks. Pigment Black 7 and Pigment Red 122 both 100% dried powders were used. The premix of these two pigments was subjected to bead milling to reduce the particle size to the nano-scale. The inkjet inks prepared were characterized for their particle size, zeta potential, purity, viscosity, surface tension, foaming properties, and pH using required analysis and spectroscopy techniques. Both inkjet inks were applied digitally on pre-treated cotton. The printing was performed on a Monna Lisa Evo Tre printer (EPSON). The printed samples were evaluated for colour fastness to light, rubbing, washing, and laundering using relevant AATCC and ISO methods. The powders of the same colour index numbers were kneaded and emulsified by a traditional ball milling method. Emulsions prepared were characterized and applied on singed, desized, scoured, bleached, and pre-treated pure cotton through a traditional rotary screen-printing method. The printed samples were evaluated for their application fastness properties for comparative studies. It was concluded that by promoting the use of green chemistry and nanotechnology, the digitally printed fabric samples displayed better print quality, increased application fastness properties and good colour gamut as compared to traditionally printed fabric samples. Moreover, the new digital printing process resulted in reduced chemical, energy and water consumption along with socio-economic, environmentally friendly effectiveness, with almost zero waste production as compared to the traditional printing method.

Water-based Formuation of Inkjet Inks Using Jute Stick-derived Submicron Carbon Particles.

Biomass pyrolysis generates significant amount hazardous gases (such as CH4 , CO, and H2 ) which are counted as highly environmental pollutants. The utilization of these gases as fuel during pyrolysis could be a suitable choice for protecting the environment. Hence, we pyrolyzed biomass, jute sticks, using a customized pilot furnace, which recycled the generated gases as fuel. We further ball-milled the obtained carbon to make submicron carbon particles. The formation of submicron carbon particles was confirmed with field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, particle size analyzer, and thermogravimetric analysis. The zeta-potential studies confirmed the high negative surface zeta potential of the prepared submicron carbon that was due to its polar functional groups (-OH, COOH, and CO), which were confirmed by Fourier-transform infrared spectroscopy. These polar functional groups facilitate their dispersion in the aqueous solution of biocompatible ethylene glycol and isopropyl alcohol to form water-based environment-friendly inkjet inks. The printing test of the developed ink was performed using a Canon printer (PIXMA; model: G3420) and compared with the performance of commercial inkjet black ink. The results indicate that the performance of the developed inkjet ink is similar to the commercial one.

A review on silver nanoparticles focusing on applications in biomedical sector

Considering that nanosilver-based materials have shown to have a novel, demanding, and promising properties appropriate for a variety of biological applications, silver nanoparticles (AgNPs) have evolved into one of the most researched and examined nanostructures created from nanotechnology in recent years. Silver nanoparticles (AgNPs) have been the subject of research due to their special characteristics, and they have considerable interest in medical applications such as highly excellent antimicrobial agents even without toxic effects, and industrial applications such as inkjet inks comprising well-unified dispersions of nano-sized silver particles that are useful for creating electronic circuits. Due to the remarkable activities shown by silver nanoparticles, they have been the focus of many researchers for developing new medications with less toxic effects. In this study, we have highlighted some entitled applications of silver nanoparticles. This review will be helpful for the researchers working on silver nanoparticles.