Textile Printing Research Articles

Multi-response mixture design applied for the formulation of a textile green camouflage ink with reproduction of a leaf green

This study establishes a proportioning model of green camouflage ink for textile screen printing to reproduce a leaf green using four high-performance inorganic pigment pastes: cobalt blue, chrome oxide green, chrome yellow, and iron red. In order to study the influence of four-color paste formulations on the camouflage performance of ink, a multi-response quadratic Scheffe mathematical model was established, and a total of 20 runs of color paste formulations were designed. Blending mixed color paste with water-based pure acrylic lotion, drying retarder, and thickener, the ink was then printed to the surface of the khaki camouflage decorative textile through screen printing. The spectral reflectance of the ink film was measured at 380∼1100 nm, and the response values were calculated. The regression model of each response was fitted using the least squares method. The model and verification experiments show that when the color paste formulation is 45.08% cobalt blue, 10.00% chrome green, 40.53% chrome yellow, and 4.39% iron red, the green camouflage ink match the leaf green well. The color difference between the green camouflage ink and the leaf green is less than 3, the reflectance ratio in the near-infrared and infrared bands is not less than 5, and the near-infrared brightness contrast with the leaf green is not more than 0.2. In addition, the green camouflage ink’s reflectivity is located in the leaf green hyperspectral channel.

Fabrication of antireflective coatings on cotton surface using dye-loaded nanoparticles for eco-friendly textile inkjet printing

Colored cellulose textiles extensively enriched human-beings' modern lives, but the problem of dye pollution has been a long-plagued trouble and still poses an alarming threat to environment and human beings. In view of this problem, herein, multi-color antireflective nanoparticles inspired by biology were prepared using dye adsorption method. Then, it was applied in cotton inkjet printing to realize the improvement of dye utilization efficiency. Results shows that, cationic poly(styrene-butyl acrylate-vinylbenzyl trimethylammonium chloride) (PSBV) nanoparticles exhibited high dye capacity. The dye-adsorbed nanoparticles possessed uniform spherical structure with an average size at about 90 nm and a surface potential over −30 mV. Turbiscan Lab measurement and high-speed camera system show that the dye-adsorbed nanoparticles possessed good stability and satisfactory jetting performance. Moreover, after the inkjet printing on cotton fabrics, the reflectance was significantly reduced with higher color strength in comparison to the same concentration of dye solution. Moreover, owing to the reaction between the nanoparticles and -OH groups on cotton fibers, durable patterns were obtained. This work provides a potential method on the preparation and application of dye/polymer nanoparticles in textile coloration for improved cleanliness and efficiency.

Exploration on ability of printable modified papers for the application in heat sublimation transfer printing of polyester fabric

In this work heat transfer papers were loaded with a new core–shell pigment based on precipitating thin shell of titanium dioxide on a core of rice husk silica ash TiO2/RHSA to be applied in dye sublimation printing of textile fabrics. Besides, 0.1% (w/w) cationic polyacrylamide (CPAM) and 1% (w/w) bentonite (Bt) were also added sequentially to improve drainage and filler retention of the paper hand-sheets made from bleached kraft bagasse pulps. The effect of the new core–shell pigment on the mechanical and barrier properties, thermal stability and surface morphology of modified paper sheets were investigated. In addition, the study of transfer printability and ease of dye release from paper to fabric in this heat transfer printing of polyester fabrics using silk-screen printing under different transfer parameters were studied. Also, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated.

Development of MATLAB code for tool path data extraction from the G code of the fused filament fabrication (FFF) parts

The area of application of Fused filament fabrication (FFF) printing is regularly expanding, and the need for simulation of the geometry and mechanical properties to reduce the experimentation time and cost is a prime objective. In FFF printing, the input CAD model is converted into an STL file and then sliced with some software in a combination of layers, and accordingly, a tool path is generated, guiding the 3D printer to print. Thus, the printed part is not the same as the solid CAD model, but it is a layered solid part with various tool path settings or slicing parameters. This difference between the solid part and the layered replica part can cause errors in the calculations of mechanical properties. All the information related to layers, infill percentage, infill pattern, walls, etc, are stored in the form of various G or M codes in a G code file. The part orientation can also be visualized with the G code file. This G code file is the soft raw material for the FFF printer to execute the printing process. The correct reading and interpretation of the G code file are very essential to understand the 3D printing process from the core. The G code file can be used for multiple applications if the data is correctly extracted from it. This can be used to model the sliced or layered solid parts or to understand the extruder motions. In this work, a MATLAB code is generated to extract the data from the G code file and get the extrusion pattern with various infill patterns and percentages. The code was tested with multiple G code flavors, available in Cura and Slic3r software, and found suitable for all. The extracted data can be used further to model the sliced or layered solid model.

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.

Quantitative Characterization of Liquid Photosensitive Bioink Properties for Continuous Digital Light Processing Based Printing.

Precise printing fabrication of bioinks is a prerequisite for tissue engineering; the Jacobs working curve is the tool to determine the precise printing parameters of digital light processing (DLP). However, the acquisition of working curves wastes materials and requires high formability of materials, which are not suitable for biomaterials. In addition, the reduction of cell activity due to multiple exposures and the failure of structural formation due to repeated positioning are both unavoidable problems in conventional DLP bioprinting. This work introduces a new method of obtaining the working curve and the improvement process of continuous DLP printing technology based on such a working curve. This method of obtaining the working curve is based on the absorbance and photorheological properties of the biomaterials, which do not depend on the formability of the biomaterials. The continuous DLP printing process, obtained from improving the printing process by analyzing the working curve, increases the printing efficiency more than tenfold and greatly improves the activity and functionality of cells, which is beneficial to the development of tissue engineering.

Triboelectric nanogenerator of 3D printed textile structure for energy harvesting application

Energy-harvesting technology, which converts discarded energy from nature into electric energy, has recently attracted attention as a solution to environmental problems, such as the exhaustion of fossil fuels, climate change, and environmental pollution. A triboelectric nanogenerator (TENG) convert mechanical shaking into electrical signals through triboelectric charging and electrostatic induction in an internal circuit, collecting wasted mechanical kinetic energy from the body, such as walking and breathing. In this study, models of a textile structure and 3D printing were used to verify the applicability of TENG of 3D Printing textile structures by outputting textile structures using 3D Printing, textile structure was modeled and 3D printed to check the TENG applicability of the 3D Printing style structure by outputting the textile structure using 3D Printing, and freestanding mode TENG was manufactured using the fabric structure output as a tribo-layer to evaluate the maximum power voltage under various conditions. The results of this study evaluated the maximum output voltage under various conditions. The thickness and load were also increased. The factors that influence the selection of materials can be identified.

Efficient preparation of single-sided structural color fabrics with asymmetric wettability, angle-dependence and patternability based on liquid photonic crystals

Liquid photonic crystals (LPCs) with structural colors have become the most promising materials for preparing structural color fabrics, which have received extensive attention in textile printing and dyeing. However, the tedious and uncontrollable preparation process for LPCs and its expensive equipment for structural color fabrics with asymmetric wettability limit the practical application of structural color materials. Herein, inspired by the Janus wettability of the unidirectional moisture transport fabric, a simple and efficient approach is reported to fabricate single-sided structural color fabrics (SSCFs) with asymmetric wettability and angle dependence. To obtain asymmetrically wetted substrate fabrics, a low-cost, high-temperature assisted spraying strategy is used to build a hydrophobic layer on one side of the fabric. The ready-to-use LPCs with target mass fraction are accurately prepared by re-dispersing the dry poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) microsphere powder and are uniformly scraped onto the hydrophilic side of the fabric to prepare SSCFs. The as-prepared samples show a brilliant and iridescent structural color, and their color is adjusted by varying the size of the P(St-MMA-AA) microspheres. The water contact angle of the front side (with structural colors) of SSCFs treated by sintering and water bath is 37°, which facilitates further encapsulation to improve the color fastness of SSCFs. Meanwhile, the photonic crystals on the fabric remain ordered. This work provides an alternative, low-cost and practical preparation scheme for the structural coloring of textiles based on LPCs.

Ionic Liquid-Assisted Ink for Inkjet-Printed Indium Tin Oxide Transparent and Conductive Thin Films

Drop-on-demand inkjet printing is used to deposit indium tin oxide (ITO) transparent and conductive thin films. ITO printable ink is prepared by dissolving indium hydroxide and tin (IV) chloride into ethanol with the assistance of acetic acid/tert-butylamine ionic liquid. Ionic liquid-assisted ITO ink exhibits a complete wetting behavior on the glass substrate and a tunable viscosity, which makes it particularly suitable for the inkjet printing fabrication of ITO thin films. After annealing at 500 °C in forming gas, ITO thin films with a sheet resistance of 99 Ω/□, a resistivity of 2.28 × 10-3 Ω·cm, and a transmittance of 95.2% in the range of 400-1000 nm can be obtained. The effects of annealing temperature on the resistivity, mobility, carrier concentration, transmittance, and optical band gap are investigated systematically. Compared with commercial ITO thin films made by conventional vacuum-based deposition approaches, these printable ITO thin films have a higher material utilization.

Nondestructive Testing of 3D Printed Fiber-Reinforced Polymeric Composites: An Experimental Critical Comparison.

Polymer matrix composite (PMC) materials produced by additive manufacturing are a promising solution with several applications in industry. The presence of defects due to fabrication could undermine the performance of the component structure. PMC performance has been extensively studied using destructive tests, but reliable nondestructive testing (NDT) techniques are essential. In this study, PMC with unidirectional fibers were 3D printed with an adapted conventional fused filament fabrication printer. The matrix material was polylactic acid, and three different reinforcement fibers were used: Kevlar®, carbon, and glass fibers. The samples were 3D printed with artificial defects, to simulate delamination's 0.5 mm thick. Four NDT techniques were explored, benchmarking the inspection of PMC envisaging an automated noncontact imaging inspection for easier result interpretation. Active pulse thermography, air-coupled ultrasounds, continuous wave terahertz, and digital X-ray were the techniques chosen, and a critical comparison is presented, evaluating the performance of each technique in the detection of defects. NDT technique diversity, complementarity, and redundancy improve inspection reliability, as there is not a single inspection technique that can cover all material defects or characteristics.

Fabrication and assessment of partial finger prostheses made using 3D-printed molds: A case study.

3D printing for custom prosthetic finger fabrication can have better fit and comfort than non-custom off-the-shelf ones while reducing fabrication labor time. The purpose of this case study was (1) to design and fabricate custom prosthetic fingers using 3D-printed molds for the treatment of partial finger amputation; (2) to evaluate patient satisfaction of the custom prosthetic fingers fabricated using 3D-printed molds and compare them to the custom prosthetic fingers fabricated through a conventional method of molding using plaster casts. The method to develop the custom prosthetic finger are as follows: (1) The shapes of the residual digits and contralateral fingers were acquired using a high-resolution 3D optical scanner. (2) Prosthetic fingers were designed by modifying the model of the residual digits and the contralateral fingers. (3) Molds of the prosthetic fingers were designed using computer-aided design software and fabricated by 3D printing. The study compared hand function tests and rehabilitation outcome surveys to evaluate the performance of the prosthetic fingers fabricated using 3D-printed molds and plaster casts. This case suggests that the prosthetic fingers fabricated using 3D-printed molds had comparable performance to the prosthetic fingers fabricated using plaster casts. The aesthetics and transparency of the prosthetic fingers contributed highly to the low satisfaction of the prosthetic fingers fabricated using 3D-printed molds.

Novel Nanopigments with a Thiazole Moiety for Printing Paper, Carton, and Polyester Fabrics: Synthesis, Characterization, and Color Strength with Comparative Study

A series of new coloring materials in nanoscale based on 5-(2-aminothiazol-5-yl) thiazol-2-amine and 5-(4-aminophenyl) thiazol-2-amine were synthesized. The nanoscale pigments were prepared using a grinding high˗energy ball-milling technique. X-ray diffraction and transmission electron microscopy were employed to determine the particle size of the nanoscale pigments (40–80 nm). The synthesized pigments in normal and nanoscale were applied in the printing of polyester fabrics. The fastness and colorimetric properties of the printed samples were carefully studied. Additionally, the synthesized pigments were applied as water-based flexographic ink for paper and carton. The hue of the color pigments L*, a*, b*, glossiness, and fastness to light were measured. The comparison of the new heterocyclic benzidine analogs in normal and nanoscale with commercial benzidine pigments demonstrated better results, particularly for the nanoscale pigments.

Thermo-mechanical properties of composite filaments for 3D printing of fabrics

The objective of this study is to manufacture composite filaments to be used in three-dimensional (3D) printing of fabrics using fused deposition modeling (FDM) method. The primary properties of a fabric are flexibility and strength which are lacking in the available 3D printed materials. Polylactic acid (PLA), thermoplastic polyurethane (TPU) and poly(ethylene) glycol (PEG) were blended in different proportions and extruded using twin-screw extruder to obtain composite filaments. The properties of the filaments were studied using various material characterization methods such as uniaxial tensile test, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). With the addition of PEG in the PLA/TPU composition, it was found that the yield stress and Young’s modulus of the composite filaments have significantly decreased compared to that of pure PLA filament. It was also noted that there was no significant difference in ultimate tensile strength whereas the elongation at break was increased by more than 500%. Using the composite filament, a plain weave fabric structure was 3D printed to investigate the printing ability of a complex structure. It is concluded that the composite filaments developed are suitable for 3D printing but non-uniformity in diameter affects the print quality and hence the overall properties of fabrics.

Polymerizable rotaxane hydrogels for three-dimensional printing fabrication of wearable sensors

While hydrogels enable a variety of applications in wearable sensors and electronic skins, they are susceptible to fatigue fracture during cyclic deformations owing to their inefficient fatigue resistance. Herein, acrylated β-cyclodextrin with bile acid is self-assembled into a polymerizable pseudorotaxane via precise host-guest recognition, which is photopolymerized with acrylamide to obtain conductive polymerizable rotaxane hydrogels (PR-Gel). The topological networks of PR-Gel enable all desirable properties in this system due to the large conformational freedom of the mobile junctions, including the excellent stretchability along with superior fatigue resistance. PR-Gel based strain sensor can sensitively detect and distinguish large body motions and subtle muscle movements. The three-dimensional printing fabricated sensors of PR-Gel exhibit high resolution and altitude complexity, and real-time human electrocardiogram signals are detected with high repeating stability. PR-Gel can self-heal in air, and has highly repeatable adhesion to human skin, demonstrating its great potential in wearable sensors.

The exploited yet legally underappreciated apparel domain of indigenous communities: Tracing WIPO's efforts and ongoing challenges

AbstractThe International Intellectual Property Rights (IPR) regime currently endeavours to protect complex subject matters ranging from art and fashion to software. This paper will specifically examine the key international instruments (issued by the World Intellectual Property Organization [WIPO] and those applicable in the European Union) governing the apparel industry. To that end, it will analyse the different instruments governing the sector and will also highlight in brief the various initiatives undertaken by the WIPO towards facilitating and harmonising the process of protecting the different facets of the fashion sector. Further, we will look at the current statistics available on the different databases and will gauge how the sector has fared. Over the course of the paper, the authors will highlight the gap in the protection granted to garments or cloth weaving techniques belonging to indigenous communities (such fashion articles fall under the broad domain of the traditional cultural expression of a community) ranging from handlooms and handicrafts to unique textile and design prints, motifs, symbols, accessories, and so on, as compared to international fashion corporations. The existing gaps would be analysed in the current international IPR regime which makes it challenging to apply the current norms and standards of IP to elements of traditional and cultural clothing of indigenous communities. It will locate a few examples of communities utilising IPR to protect and promote their cultural heritage in the garment industry. Continuing on this tangent, the paper will look at how the IP regime can be adequately expanded to incorporate the needs and interests of indigenous communities and promote their fashion and culture. The final part of the paper will be conclusive in nature.

Soft dielectric actuator produced by multi‐material fused filament fabrication 3D printing

AbstractDielectric elastomer actuators rely on Coulomb forces for their actuation. They are promising candidates when it comes to the manufacture of electrically driven soft and lightweight robotic devices, which can undergo large movement. However, their commercial availability and hence their technological relevance are still rather limited due to several reasons: in‐depth material knowhow in terms of electrical and mechanical behavior required; materials have to be available in thin sheets; complicated and error prone fabrication; limited design freedom. In order to change this, this paper presents a soft dielectric actuator fully produced by fused filament fabrication. Additive manufacturing with conventional fused filament fabrication machines offers the potential for the production of personalized dielectric actuators which are easily accessible and comparably cheap. The only requirement is a fused filament fabrication printer with multi‐material capability. Focusing on a mass customization of the 3D printed actuators, exclusively commercially available devices and filaments without any modifications are used. In particular, the 3D printed prototypes are characterized in terms of the maximum displacement depending on the electrode printing direction. As a showcase example, a soft dielectric gripper made of two 3D printed actuators is developed. Comparable with other dielectric elastomer actuators, a maximum displacement of 42% is reached.

Wastewater from textile digital printing as a substrate for microalgal growth and valorization

This study aims at evaluating an innovative biotechnological process for the concomitant bioremediation and valorization of wastewater from textile digital printing technology based on a microalgae/bacteria consortium. Nutrient and colour removal were assessed in lab-scale batch and continuous experiments and the produced algae/bacteria biomass was characterized for pigment content and biomethane potential. Microbial community analysis provided insight of the complex community structure responsible for the bioremediation action. Specifically, a community dominated by Scenedesmus spp. and xenobiotic and dye degrading bacteria was naturally selected in continuous photobioreactors. Data confirm the ability of the microalgae/bacteria consortium to grow in textile wastewater while reducing the nutrient content and colour. Improvement strategies were eventually identified to foster biomass growth and process performances. The experimental findings pose the basis of the integration of a microalgal-based process into the textile sector in a circular economy perspective.

Characterization of microfibers originated from the textile screen printing industry

Textile industries are known for their higher levels of environmental impact due to their nature of processes. However, the impact of the textile manufacturing process on emerging microfiber pollution is less explored. This research focuses on analyzing the microfiber release behavior of textile fabrics during the screen printing process. The effluent released in the screen printing process was carefully collected at the point of origin and characterized for microfiber count and length. The analysis revealed a higher amount of microfiber release of 1,394,205.22 ± 426,262.50 microfibers/L of printing effluent. This result was 25 times higher than previous research that analyzed the influent of textile wastewater treatment plants. The lower water usage throughout the cleaning process was noted as the main reason for the higher concentration. Based on the total amount of textile (fabrics) processed, it was noted that the print process releases 23.10 ± 7.06 microfibers/sq.cm of fabric. The majority of identified microfibers were in the length range of 100–500 μm (61.25 %), with an average length of 519.1 μm. The use of adhesives and raw cut edges of the fabric panels were noted as the primary reason for microfiber emission, even in the absence of water. Significantly a higher amount of microfiber release was noted with the lab-scale simulation of the adhesive process. A comparative analysis of microfiber quantity with industry effluent, lab-scale simulation, and household laundry of the same fabric showed that, out of all phases, the lab-scale simulation caused higher fiber release (1156.63 ± 21.74 microfibers per sq.cm of fabric). This shows that the adhesive process during the printing process was the key reason for higher microfiber emissions. When domestic laundry and the adhesive process were compared, domestic laundry showed significantly lesser release (320.31 ± 49 microfibers/sq.cm of fabric). Though various studies have explored the impact of microfiber released from domestic laundry, the results of the current study alarm that the textile printing process is an underestimated source of microfiber release into the environment, which requires greater attention.

Electromagnetic Modeling Strategy Supporting the Fabrication of Inkjet-Printed Chipless RFID Sensors

Inkjet printing fabrication techniques can be used for the manufacturing process of chipless radio-frequency identification RFID sensors. With respect to traditional silicon-based fabrication, flexible electronics induce the possibility to experiment new substrates and conductive materials. With the development of high-conductive nano-inks the low sintering temperature required to process them results compatible with a large variety of substrates. However, the requirements for the conductivity of the metallized printed patterns are particularly stringent for applications where the working frequency is high, like in the case of common chipless RFID tags working in the frequency range 3-10GHz. In chipless RFID systems, the higher the conductivity of the conductive parts and the better the signal response of the tag. However, in printed chipless RFIDs the conductivity can only give a partial indication of the goodness of the tag. The tag response is dependent on the sheet resistance, which is not only related to the conductivity of the ink but also to the thickness of the printed pattern. Therefore, if a sufficiently high-conductive nano-ink is selected, the signal efficiency of the printed tag can be further improved by making an evaluation based on the thickness of the patterns. The objective of this study is to propose a strategy for evaluating the signal response efficiency in inkjet-printed chipless tags by means of a first quantification of the average thickness of the printed layer, which is used to feed a finite element method simulation model to give the manufacturer an idea of the optimal number of layers to be printed in order to have a strong signal response.

The selective and enhanced adsorptive behaviors of supramolecular recrystallized 1,3,5-benzenetricarboxylic acid assembled nano-bacterial cellulose

The effluent discharge produced in the textile printing and dyeing, leather and other fields, will cause the irreversible environmental pollution and extremely threatening safety of living organisms. The appropriate and efficient disposal method of dyestuff originated wastewater has been widely concerned in the past decades. In this study, the recrystallization of 1,3,5-benzene tricarboxylic acid (RCTMA) was put forward via a hydrothermal method to form the supramolecular RCTMA-based hexamer and thereafter assembled into the porous nano-bacterial cellulose (NBC) to construct the RCTMA@NBC composite. The morphology and surface properties of RCTMA@NBC were examined by scanning electron microscope, X-ray diffraction, and Fourier transform infrared spectroscopy. This RCTMA@NBC was employed to adsorb methylene blue (MB) adjusting the pH, temperature, and dosage of adsorbent. The result showed the maximal absorption capacity of RCTMA@NBC appeared under pH = 7.1 and higher temperature will hinder the adsorption of dyes. Moreover, the adsorption isotherms and kinetics were evaluated which was more confirmed to Langmuir model and quasi-second-order kinetic equation, and the simulated maximum adsorption capacities of MB was 1162.12 mg/g. Moreover, cationic golden XGL and anionic brilliant crocein were selected to further verify the distinct adsorptive behavior. The excellent affinity towards cationic dyes proved the easy combination was based on the chemical force originated from mutual attraction between opposite charges, π–π interactions, and H-bonding, whereas the poor attraction for brilliant crocein was due to the electrostatic repulsion between sulfonic and carboxyl groups. The synthesized RCTMA@NBC possesses higher efficiency and selective adsorption, which exhibits the promising potential in the field of precise treatment of organic dye wastewater.