Pigment Ink Formulation, Tests and Test Methods for Pigmented Textile Inks

Cotton, polyester, and cotton polyester blended woven fabrics were printed using an ink jet print using by means of a prepared pigment ink. Literature indicated that the development of insoluble pigment-based inks presents enormous challenges to the ink formulator. Meanwhile, pigments face several application problems in terms of their dispersion stability within the ink formulation, and consequently blocking the nozzles within the inkjet print head.The study was done on route bases: Formation of pigment ink for textile, Tests and test methods for pigmented textile inks, Limitations and Approaches in Development of Pigment Based Inks Keywords: Binder system, Dispersing agent, Tests and test methods, Ink formulation, pre-and post-treatments

Printing of cotton fabrics using microwave irradiation

Irradiation Microwave was used in fixation of pigment prints on cotton fabrics with a colour strength parameters comparable with the previous research obtained in case of thermo-fixation procedures. However printing pastes was introduced to the fabric via screen printing methods. The printed fabrics was subjected to irradiation microwave for different periods of time at microwave power. Results of both covered and uncovered ranges from 3.8 to 10.70 and 1.66 to 8.20.Also the effect of irradiation microwave on printed cotton fabrics with yellow pigment for 6 min, for both covered and uncovered ranges from 3.50 to 15.52 and 5.20 to 16.80, likewise fastness properties of the cotton fabrics printed with yellow pigment fixed either by optimum conditions for irradiation microwave for both washing and rubbing which ranges from 4/5 for colour change(cc) and for colour staining(cs) which is 4. In order to compare the initial result, another samples of cotton fabrics were printed with the same paste, dried and subjected to fixation procedure. The colour strength of the printed cotton fabrics fixed through irradiation microwave was found to be time and microwave power dependent. Results of this investigation clarified also that, regardless of the time of microwave, covering the pigment printed cotton fabric samples with covered and uncovered sample. Furthermore, the influence of reduction of the particle size of pigment yellow colour to the nano-scale on the colour strength and overall fastness properties of cotton fabrics printed and fixed using irradiation microwave was determined

Chitosan and improved pigment ink jet printing on textiles

The purpose of this research was to explore two ways of the application of chitosan, a biopolymer, for ink jet printing of textiles. 1) To apply chitosan as a post-treatment on the fabric ink jet printed with pigment based inks for the fixation of pigments on the fabric. 2) To incorporate chitosan as a binder in pigment based ink jet ink formulations. The incorporation of chitosan was carried out in two ways. 1) Direct addition of chitosan into the ink formulations containing surface modified pigments. 2) Preparation of chitosan encapsulated pigment nanoparticles using complex coacervation technique and using these nanoparticles for the formulation of ink jet ink. The degree of deacetylation (DD) was determined using FTIR spectroscopy. Various protocols proposed by researchers were used to determine the DD of chitosan samples used in the present study. The protocol proposed by Raut was found to be fairly accurate in determining the DD of chitosan samples. The molecular weight of chitosan was estimated using dilute solution viscometry method. The characterisation of the film forming ability of chitosan was evaluated using scanning electron microscopy (SEM). The colour strength (K/S), colour difference, colour characteristics and colour fastness to laundering and rubbing of ink jet printed fabrics post treated with chitosan were evaluated using standard methods. Post-treatment (pad-dry-cure method) of cotton fabric ink jet printed with pigment based inks revealed that chitosan could effectively fix the pigments on cotton compared to the commercial textile binders and the water-soluble derivative of chitosan. The chemical interaction between chitosan and cotton fabric was illustrated by FTIR-ATR analysis and through determination of carboxyl group content. The ink jet printed cotton fabric post treated with 3gpl chitosan (MW 156,156) maintained almost 86% of bacterial reduction against Klebsiella Pneumoniae even after 50 launderings. Inks containing chitosan were formulated and were found to be stable in terms of mean particle size and viscosity over a period of one month and for 4 freeze/thaw cycles. A magenta ink containing chitosan was selected for ink jet printing of cotton fabric. It was found that the DF was around 97% for magenta ink containing chitosan compared to around 53% fixation for magenta ink without chitosan on cotton fabric. Surface modified carbon black pigment with carboxylated (COO-) surface functionality was selected to prepare chitosan encapsulated pigment nanoparticles by complex coacervation technique. Chitosan encapsulated pigment nanoparticles with mean particle size diameter of 876 nm and 742 nm were formed when 5 ml of 0.1% w/v pigment was mixed with 2ml and 3ml of 0.1% w/v chitosan, respectively. However, no correlation was found between the particle size of the nanoparticles formed and the concentration of chitosan. The DF with ink containing chitosan encapsulated pigment nanoparticles was found to be around 98% while the blank ink with only surface modified carbon black pigment showed 44% fixation

Print Quality of Ink Jet Printed PVC Foils

Digital printing technique is used for a wide variety of substrates, one of which are PVC foils. Samples used in this research were printed by digital ink jet printing technique using Mimaki JV22 printing machine and J-Eco Subly Nano inks. As printing substrates, two different types of materials were used (ORACAL 640 - Print Vinyl and LG Hausys LP2712). A test card consisting of fields of CMYK colours was created and printed, varying the number of ink layers applied. Samples were exposed to light after the printing process. Spectrophotometric measurements were conducted before and after the light treatment. Based on spectrophotometricaly obtained data, colour differences ΔE2000 were calculated. Results showed that increasing number of layers, as well as the right choice of substrates, can improve the behaviour of printed product during exploitation

Soft electronics by inkjet printing metal inks on porous substrates

Soft electronic devices enable new types of products for an ergonomic interaction of humans with a digital environment. The inkjet (droplet on demand) printing of electrically conductive ink in plural on soft substrates such as paper, textile, and polymers is a promising route for the prototyping and small-scale production of soft electronics that is efficient, cost-saving, and provides a rapid turnaround due to its fully digital workflow. The choice of materials and processing parameters is challenging, however, due to the combined complexity of metal-containing inks, their dynamics during droplet ejection, the active role of the porous substrate, and possible post-deposition steps. This review focuses on recent developments in inkjet printing of metal inks onto soft, porous substrates and their applications. The first section discusses the general principles in the inkjet printing of metal inks, including drop formation and jetting, wetting, and post treatment processes. The second section deals with the effect that the porosity of substrates has on the drying, diffusion, and adhesion of inks. Finally, current challenges and achievements of inkjet-printed, metal-containing inks are discussed

An investigation of the performance of photochromic dyes and their application to polyester and cotton fabrics

Six commercial photochromic dyes were applied to polyester and, to a lesser extent, cotton fabrics by different dyeing and printing methods. The photochromic performance of the dyed and printed fabrics was investigated in terms of the degree of photocoloration, background colour, fading characteristics, fatigue resistance and storage stability. A traditional aqueous-based disperse dyeing method was used to apply the photochromic dyes to polyester fabric. Solvent-based dyeing methods also were investigated for application of the photochromic dyes to polyester fabric. Solvent-based inks were formulated and applied to polyester and cotton fabrics by digital inkjet printing. The photochromic performance and colour fastness to light and washing of the photochromic fabrics were evaluated and comparison made. UV/visible spectra of the commercial photochromic dyes in a range of solvents were obtained and interpreted in terms of solvent polarity. On the basis of this study, the photochromic performance of the fabrics was improved by selecting the appropriate application solvents which transferred minimum background colours onto the fabrics. A new method of evaluating lightfastness of photochromic fabrics was established, aimed at replacing the conventional method by an instrumental method. This method was based on comparing the decrease in the degree of photocoloration of photochromic fabrics after light exposure with measured values of the colour differences of the blue wool references after fixed periods of light exposure. Two photochromic dyes were synthesized by azo coupling of a spironaphtho[2,1-b]oxazine with diazonium salts obtained from p-nitroaniline, and m-nitroaniline. Molecular modeling of the new photochromic systems, which are referred to as azospirooxazine dyes, showed that the dyes were predicted to have the potential to show photochromism. Thus, the photochromism of the azospirooxazine dyes in a range of solvents was investigated. The investigations showed that the dyes performed differently in different solvents in terms of the hue, the rate of the photochromic colour change and the colour reversibility