Digital Printing Research Articles

Digital Light Process 3D Printing of Magnetically Aligned Liquid Crystalline Elastomer Free-forms.

Liquid crystalline elastomers (LCEs) are anisotropic soft materials capable of large dimensional changes when subjected to a stimulus. The magnitude and directionality of the stimuli-induced thermomechanical response is associated with the alignment of the LCE. Recent reports detail the preparation of LCEs by additive manufacturing (AM) techniques, predominately using direct ink write printing. Another AM technique, digital light process (DLP) 3D printing, has generated significant interest as it affords LCE free-forms with high fidelity and resolution. However, one challenge of printing LCEs using vat polymerization methods such as DLP is enforcing alignment. Here, we document the preparation of aligned, main-chain LCEs via DLP 3D printing using a 100 mT magnetic field. Systematic examination isolates the contribution of magnetic field strength, alignment time, and build layer thickness on the degree of orientation in 3D printed LCEs. Informed by this fundamental understanding, DLP is used to print complex LCE free-forms with through-thickness variation in both spatial orientations. The hierarchical variation in spatial orientation within LCE free-forms is used to produce objects that exhibit mechanical instabilities upon heating. DLP printing of aligned LCEs opens new opportunities to fabricate stimuli-responsive materials in form factors optimized for functional use in soft robotics and energy absorption.

Quantitative analysis of the color accuracy and reproducibility in digital textile printing: Discrepancies within color reproduction media

In this study, the overall color reproducibility of a digital textile printing (DTP) process was investigated within a wide range of color gamuts, and the design color factors influencing color reproduction in the initial design stage of DTP were analyzed. During the DTP process, digital image samples, display samples, and fabric samples, each representing 1296 colors, were created. The color reproduction ranges of these samples and the discrepancies in their lightness, chroma, hue, and overall color were analyzed. It was found that the display samples exhibited the widest color reproduction range, particularly in terms of lightness and chroma. In contrast, the fabric samples showed the narrowest color reproduction range. Furthermore, it was shown that color reproducibility was significantly reduced when the medium transitions from display to fabric during the DTP process, with an average overall color difference of 24.34 Δ E*ab being detected between the display and fabric samples. The low color reproducibility of this DTP process was particularly influenced by the K ratio and the L*10 and C*ab,10 values of the initial design. More specifically, the K ratio and the L*10 value of the initial design imparted significant effects on the lightness reproducibility, whereas the C*ab,10 value of the initial design had a significant impact all on the lightness, chroma, hue, and overall color reproducibilities.

REVIEW OF TEXTILE PRINTING: DIFFERENTIATION OF BLOCK, SCREEN & DIGITAL PRINTING

In India is well known for its traditional culture and art features. Hand block printing techniques are practiced in Rajasthan. Hence, the block printing is a slow process. Printing process of desired pattern is defined and repeated. The various styles for block printing are significant of the country in rich culture and heritage. It is a unique of each region will have a different variations of traditional craft. That was crafted for propagating Hindus mythology of depicted folk style story transform of imagination forms of God and goddess in literature. In this article, we will discuss about block printing, the development digital printing and manual of screen printing. The comparison of these three styles of textiles printing. It is a oldest method of art craft. The economics of ink jet printing are the main driver of digital printing technique. The costs of ink jet printing are lower for short run lengths than in traditional screen printing. This switches for longer runs production. Short-run textile printing commissions are the main source of jobs for small to medium scale textile producers in Ghana. And manual screen printing is the main process employed by these small-scale textile printers. These layers of limitations negatively affect the overall outcome of the prints. This is because, the large-scale textile factories in Ghana can print a minimum of 2400 yards due to their machine settings, calibration and running cost to make the least returns. KEYWORDS: Hand block printing, natural dyes, screen printing, techniques, digital printing.

Digital Textile Printing and Batik Preservation: A Bibliometric Analysis via VOSviewer

This study examines digital textile printing as an opportunity and, simultaneously, a threat to batik preservation. The study used a bibliometric approach through VOSviewer computational mapping analysis. Article data is obtained from the Google Scholar database using the Publish or Perish reference manager application. The title and abstract of the article are used to guide the search process by referring to the keywords "digital textile printing" and "batik preservation." From the search results of 1000 articles, we found 771 articles that were considered relevant. The study period used as study material is Google Scholar-indexed articles for the last 5 years (2018–2023). The results showed that research related to textile digital printing and batik preservation identified several terms: study, batik, batik preservation development, ink, textile, technology, fabric, digital printing, digital textile printing, and application. From the clusters contained in the network visualization, it can be known: Cluster 1 has 37 items and is marked in red; Cluster 2 has 33 items and is marked in green; Cluster 3 has 27 items and is marked in blue; Cluster 4 has 21 items and is marked in yellow; Cluster 5 has 19 items and is marked in purple; Cluster 6 has 14 items and is marked in light blue; Cluster 7 has 14 items and is marked in orange; Cluster 8 has 12 items and is marked in brown; and Cluster 9 has 2 items and is marked in light purple. Based on the analysis of the development of digital printing, textile publications in the last 5 years show frequent fluctuations. In 2018–2019, it experienced a significant increase from 116 to 200, and then in 2020, the condition decreased to 167. From 2021 to 2022, there was a significant increase of 198 and 238, respectively. We examined how many articles have been published about digital textile printing and its relation to the issue of batik preservation using VOSviewer. This review can serve as a starting point for research related to other materials, especially technological developments related to textiles and batik.

A Comparative Study of Traditional and Computer-aided Surgical Simulation Guides in Orthognathic Correction of Bimaxillary Protrusion.

To compare the efficacy of traditional occlusal guides with computer-aided surgical simulation (CASS) guides in enhancing postoperative outcomes for patients with bimaxillary protrusion. This retrospective study evaluated 34 patients undergoing anterior maxillary and mandibular subapical osteotomy at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences. Fourteen patients were treated using traditional occlusal guides, whereas 20 patients were treated with CASS guides (median age 28.6 years, median follow-up 259 days). Pre and postoperative cephalometric indicators were measured using cephalometric software. Data analysis was conducted using SPSS 14.0, with significant differences determined at P < 0.05. All 34 patients experienced primary healing without complications. Follow-up indicated significant improvements in key cephalometric measurements in the CASS group compared with the traditional group, including mandibular position (SNB angle, P < 0.001), jaw relationship (ANB angle, P < 0.001), facial angle (FH-NPo, P = 0.002), and condyle-to-sella distance (Co-S, P = 0.024). The CASS group also showed better aesthetic outcomes, with significant reductions in overjet (P = 0.012), overbite (P = 0.001), and improved alignment of upper and lower incisors (U1-L1 angle, P = 0.031). CASS-guided surgery offers a superior alternative to traditional methods for treating bimaxillary protrusion, providing more precise and aesthetically pleasing results. This study highlights the significant advantages of using advanced digital simulation and 3-dimensional printing technologies in orthognathic surgery.

4D-printed shape-programmable [H+]-responsive needles for determination of urea

Four-dimensional printing (4DP) technologies are revolutionizing the fabrication, functionality, and applicability of stimuli-responsive analytical devices. More practically, 4DP technologies are effective in fabricating devices with complex geometric designs and functions, and the degree of shape programming of 4D-printed stimuli-responsive devices can be optimized to become a reliable analytical strategy. Although shape-programming modes play a critical role in determining the analytical characteristics of 4D-printed stimuli-responsive sensing devices, the effect of shape-programming modes on the analytical performance of 4D-printed stimuli-responsive devices remains an unexplored subject. We employed digital light processing three-dimensional printing (3DP) with acrylate-based photocurable resins and 2-carboxyethyl acrylate (CEA)-incorporated photocurable resins for 4DP of the bending, helixing, and twisting needles. Upon immersion in samples with pH values above the pKa of CEA, the electrostatic repulsion among the dissociated carboxyl groups of polyCEA caused swelling of the CEA-incorporated part and [H+]-dependent shape programming. When coupling with the derivatization reaction of the urease-mediated hydrolysis of urea, the decline in [H+] induced shape programming of the needles, offering reliable determination of urea based on the shape-programming angles. After optimizing the experimental conditions, the helixing needles provided the best analytical performance, with the method's detection limit of 0.9 μM. The reliability of this analytical method was validated by determining urea in samples of human urine and sweat, fetal bovine serum, and rat plasma with spike analyses and comparing these results with those obtained from a commercial assay kit. Our demonstration and analytical results suggest the importance of optimizing the shape-programming modes to improve the analytical performance of 4D-printed stimuli-responsive shape-programming sensing devices and emphasize the benefits and applicability of 4DP technologies in advancing the development and fabrication of stimuli-responsive sensing devices for chemical sensing and quantitative chemical analyses.

Shape-programmable hard-magnetic soft actuators with high magnetic particle content via digital light processing method

In this work, we developed a novel hard-magnetic photosensitive suspension with high solid loadings of 50 wt% for digital light processing 3D printing. The suspension combining photosensitive resin and reactive diluent can retain stability for 6 h. The printed materials from the suspension achieve a low modulus of below 900 kPa and high remanence of 83.7 kA/m. The suspension’s cure behavior was studied in detail to obtain the optimal printing parameters. The printing error of the small structures with feature size of about 1000 μm is kept below 20 %. Moreover, we proposed an efficient magnetization programming strategy for hard-magnetic soft actuators with desirable shapes based on the rod model considering the non-magnetic load. The accuracy and reliability of the strategy are verified by the experiment results. Finally, we designed and fabricated a “flower” using our method, achieving its closing action in accordance with the prescribed shape.

Simultaneous Color- and Dose-Controlled Thiol-Ene Resins for Multimodulus 3D Printing with Programmable Interfacial Gradients.

Drawing inspiration from nature's own intricate designs, synthetic multimaterial structures have the potential to offer properties and functionality that exceed those of the individual components. However, several contemporary hurdles, from a lack of efficient chemistries to processing constraints, preclude the rapid and precise manufacturing of such materials. Herein, the development of a photocurable resin comprising color-selective initiators is reported, triggering disparate polymerization mechanisms between acrylate and thiol functionality. Exposure of the resin to UV light (365nm) leads to the formation of a rigid, highly crosslinked network via a radical chain-growth mechanism, while violet light (405nm) forms a soft, lightly crosslinked network via an anionic step-growth mechanism. The efficient photocurable resin is employed in multicolor digital light processing 3D printing to provide structures with moduli spanning over two orders of magnitude. Furthermore, local intensity (i.e., grayscale) control enables the formation of programmable stiffness gradients with ≈150× change in modulus occurring across sharp (≈200µm) and shallow (≈9mm) interfaces, mimetic of the human knee entheses and squid beaks, respectively. This study provides composition-processing-property relationships to inform advanced manufacturing of next-generation multimaterial objects having a myriad of applications from healthcare to education.

Modified cellulose nanofibrils as enhancers for thin UV-curable matte coatings on digital printing decorative panels

To enhance the surface properties of a thin ultraviolet (UV)-curable matte coating film (less than 20 µm) for the digital printing decorative panels, the aldehyde-containing cellulose nanofibril (CNF) coupled with hyperbranched poly (amido amine) grafting was selected as a reinforcing agent. The viscoelastic properties of the coating and physical and mechanical characteristics of the corresponding decorative panels were evaluated. The results revealed that the incorporation of the modified CNF increased the viscosity of nanocomposite coatings at low shear rates, while at shear velocities exceeding 10 1/s, the viscosity approached that of the pure coating. The modified CNFs dispersed well in coatings and the nanocomposite coating showed excellent stability. Moreover, the incorporation of CNF clearly enhanced the tensile strength of the coating film. Additionally, the modified CNF physically and chemically bonded to the polymer chains within the UV-curable coating. Furthermore, the modified CNF facilitated the optimal distribution of silica in the acrylic polymer when added at 5 wt%. The panels with the modified matte coating exhibited marginally improved clarity compared to that of the original boards. Moreover, the inclusion of the modified CNF resulted in reduced gloss, enhanced hardness, and improved yellowing resistance compared to the original panels, thereby enhancing the quality of the new product.

Direct Printing of Disperse Dye Inks to Polyester Fabrics without Chemical Pretreatment.

Direct inkjet digital printing is a relatively green and environmentally friendly textile printing method with a wide range of applications in the textile printing and dyeing industry. However, pretreatment of the fabric is required before digital printing, which will generate certain energy consumption and wastewater. In this study, a digital direct inkjet printing method was developed to improve the printing accuracy of poly(ethylene terephthalate) (PET) fabrics without any pretreatment. A kind of direct inkjet printing ink was prepared by the response change in temperature viscosity. The increase in viscosity inhibits ink bleeding on the fabric, thereby improving printing accuracy. A thermosensitive direct inkjet printing disperse dye ink was prepared by adding cetyltrimethylammonium bromide (CTAB) and 3-methylsalicylic acid (3MS) to the ink. By evaluating the changes in the ink particle size, shear viscosity, and temperature viscosity, it was found that this thermosensitive ink has an excellent average particle size and special changes in viscosity with increasing temperature. When this heat-sensitive ink is printed on a polyester fabric, the fabric does not need pretreatment to improve the clarity of printing, and the printed fabric has satisfactory color fastness to friction and washing.

Wearing the mandibular advancement orthosis and dental movements: Contribution of a digital monitoring protocol

AbstractObjectivesOral appliance (OA) has been increasingly used for the treatment of obstructive sleep apnoea hypopnea syndrome (OSAHS). OAs work by propelling the mandible, increasing the upper airway calibre and reducing collapsibility. While they have shown efficacy in reducing OSAHS, long‐term use can lead to adverse effects, such as dental displacement. The present study focuses on the impact on dental displacements of the NARVAL® computer‐aided design and manufacturing OA from the ResMed laboratory.Materials and MethodsThe study included 39 patients aged 18 or older who were treated for OSAHS using OAs initiated between 2019 and 2021 and had initial digital dental impressions. A new digital print was taken for each patient using the TRIOS 4 Wireless intra‐oral scanner from 3SHAPE. Dental displacement was measured using a 3D system's GEOMAGIC design X 3D reverse engineering software. The study analysed different blocks of teeth in both the maxillary and mandibular arches. Statistical analysis was conducted to determine the significance of dental displacements.ResultsPatients had been wearing the OA for an average of 2.5 years. The study found dental displacements in both the maxillary and mandibular arches. However, these displacements were not statistically significant. Qualitative analysis revealed palatoversion and vestibuloversion, while quantitative analysis showed minor dental displacements.ConclusionThis study on patients wearing the NARVAL® OA for an average of 2.5 years found dental displacements in both the maxillary and mandibular arches. However, these displacements were not statistically significant. The results suggest that the OA, designed using a complete digital workflow, did not significantly impact dental positions. To confirm the impact, further investigations with larger sample sizes, an exclusively digital protocol and a control group are required.

Environmental Sustainability Analysis of Rotary-Screen Printing and Digital Textile Printing

Worldwide concern regarding the need for more sustainable textile supply chain prompted emphasis on innovation in the coloration process, often considered the most problematic segment of the supply chain. Digital textile printing, an emerging coloration technology, has the potential to improve sustainability significantly. This study undertakes an environmental sustainability analysis that compares the impacts of rotary-screen printing, the traditional, more established printing method, and digital textile printing. Researchers partnered with Creditex S.A.A., a vertically integrated textile company from Peru, to perform the research in a realistic factory setting. Creditex printed a 16-color design for an order of 1000m cotton fabric with reactive dye occupying both rotary-screen printing and digital textile printing and collected environmental impact data throughout the production process, including consumption, usage, and wastage. The findings suggest that digital textile printing is favorable to rotary-screen printing in terms of environmental sustainability impacts within the research context.

3D printed microcrystalline CsI:Tl composite scintillating thin films for X-ray imaging

The utilization of additive manufacturing techniques, especially Digital Light Printing (DLP), in fabricating CsI:Tl scintillator films demonstrates considerable potential for streamlining the production of scintillators tailored for X-ray imaging applications. This research focuses on the fabrication of CsI:Tl-based composite plastic scintillator thin films. In this study, circular films measuring 1-inch in diameter and 0.1 mm & 0.2 mm in thickness are being produced and tested for gamma photon counts under alpha and gamma radiation. To establish the stopping power range of the films, a Monte Carlo based GEANT4 simulation has been carried out. Additionally, investigations into their suitability for X-ray imaging applications are being conducted, revealing the spatial resolution of the films (0.2 and 0.1 mm) between 100 and 130 μm and 1.26 lp/mm with a contrast range of 4.0–12.3 %. The observed decrease in spatial resolution and contrast for the 0.2 mm thick film is attributed to the thickness increase exacerbating the scattering phenomenon while simultaneously enhancing the X-ray stopping power. This highlights the significance of inherent trade-off between maximizing spatial resolution and compromising light yield of 0.1 mm films compared to the 0.2 mm thick film. By utilizing 3D printing, this approach offers a cost-effective and time-efficient method for producing thin-film scintillators with enhanced flexibility and customization options compared to conventional methods.

3D Printed Metal Organic Framework Hydrogel for Dye Adsorption and Gas Sensing

AbstractMetal organic frameworks (MOFs) have tunable chemical structures, orderly pore structures, and modifiable surface functional groups making them a promising material for environmental remediation. However, their rigid powder morphology poses significant challenges for customizing MOF structures with adjustable mechanical properties. Here, we synthesis the stretchable UV‐curable MOF hydrogels through high‐resolution digital light processing 3D printing, and evaluated its adsorption effect on seven common dyesand.The results showed that it had selective adsorption effect on methylene blue (MB), and the adsorption effect increased with the increase of the initial concentration of MB: its adsorption capacity on 6 mgL−1, 12 mgL−1 and 24 mgL−1 MB solution reached 13.55 mgg−1, 26.31 mgg−1 and 50.70 mgg−1 respectively. Compared to powdered MOFs, the 3D‐printed MOF (Cu‐BTC) exhibited superior adsorption for dye and radioactive pollution, with methylene blue adsorption increasing from 8.93 mgg−1 to 25.05 mgg−1 and I2 adsorption from 141.56 mgg−1 to 792.65 mgg−1. Furthermore, the 3D‐printed MOF structure proved easily cleanable with dilute HCl and reusable over five times without degradation. In addition, our study highlighted the suitability of the 3D‐printed MOF for CO2‐sensing devices, demonstrating its broad applicability in environmental remediation and sensing technology.

The (im)possibility of communication with nonhuman beings: with digital screen printing of luminous bacteria

In the current media environment, John Durham Peters emphasizes the importance of non-verbal communication and notes that underpinned by digital technology, “media” is returning to its original meaning as the milieu that surrounds living beings. To concretize and critically discuss this idea, this paper examines the artworks created by the authors, which incorporate microorganisms into digital technology. These works applied luminous bacteria as ink to digitally screen print text and images. The first work, A Medium for Images or Luminous Bacteria (2022), prints Japanese text with luminous bacteria ink. The second work, ‘イ(I)’ (1926) by BioLuminescent Bacteria (2024), recreates the first image in the history of Japanese television, ‘イ(I)’, with luminous bacteria. This paper compares and analyzes these practices in light of classical media theory, including the work of William Ivins Jr. and Marshall McLuhan. The paper introduces another work, Grow.|Glow. (2023), to further expand the discussion to contemporary digital media. Finally, drawing on the recent arguments of Anna Tsing and Antonio Damasio, we elucidate the critical implications that the works of luminous bacteria bring to the current media environment.

The application of synthetic wollastonite in digital light processing 3D printing

In this study, 3D printable organic-inorganic resins were developed using glycerol dimethacrylate, which can be synthesised from glycerol obtained as a by-product of the biodiesel production process, and wollastonite synthesised from reagent-grade materials, the by-product of the aluminium fluoride manufacturing process, silica gel waste or natural rock. The developed recyclable waste-based material was proven to be compatible with the widely available desktop DLP 3D PICO2 39 printer. It allowed straightforward additive manufacturing of true 3D structures with sub-millimetre spatial definition using standard printing parameters. This opens the way for the production of inorganic objects from reusable industrial waste.

Digital Light Processing of Thermoresponsive Hydrogels from Polyproline-Based Star Polypeptides.

The first report of star poly(L-proline) crosslinkers is disclosed for digital light processing 3D printing of thermoresponsive hydrogels. Through chain end functionalization of star poly(L-proline)s with methacryloyl groups, access to high-resolution defined 3D hydrogel structures via digital light processing is achieved through photoinitiated free radical polymerization. Changing the poly(L-proline) molecular weight has a direct influence on both thermoresponsiveness and printability, while shape-morphing behavior can be induced thermally.

Innovative integration of chitosan biopolymer for felt-free woolen fabric: A synergistic approach with digital textile printing

Wool, renowned for its ancient legacy and unique attributes, is a prized textile fiber with versatile applications in various domains. However, the susceptibility to shrinkage due to the scaly structure of overlapping cells (scales) in the cuticle poses a challenge, prompting the widespread adoption of chlorination to enhance resistance to felting and shrinkage. This research explores the potential of chitosan biopolymer as an effective anti-felting agent and enhancer of wool dyeability. With its non-toxic, biocompatible, and biodegradable properties, chitosan is a promising substitute for various textile finishes. Recent innovations include chitosan’s contribution to improving the digital printing process, particularly in enhancing color strength and sharpness on cotton fabric. Identifying a research gap in exploring the synergistic potential of chitosan for anti-felting, this study introduces an alkaline hydrogen peroxide pre-treatment to enhance chitosan absorption through the pad-dry-cure method. Chitosan, acting as a binder, is strategically applied in the pre-treatment to fix pigments with reactive inks during inkjet printing. Critical process parameters, such as chitosan concentration, curing temperature, and time, were optimized for area shrinkage (%) to achieve a felt-free property for wool. Subsequent optimization focuses on color strength, print sharpness, and washing durability of digitally printed patterns. The results obtained from this research were quite promising in terms of K/S value, wettability, pilling behavior, tensile strength, edge sharpness, washing fastness, and fabric shrinkage resistance.

Impact of ultraviolet radiation energy curing UV primer on adhesion of bamboo lumber surfaces and colorimetry of UV inkjet coatings

ABSTRACT The application of UV digital inkjet printing technology in the home furnishing industry has greatly enriched the diversity of decorative panels. Controlling the UV radiation energy curing UV primers process has a significant impact on the performance of UV printing coatings on bamboo surfaces. The results showed that the UV radiation energy is in the range of 60∼300 mJ cm−2, the adhesion of the UV primer on the surface of bamboo is the best when it is controlled at 180 mJ cm−2, which reaches the standard of 0 level; when the radiation energy reaches 240 mJ cm−2, the content of oxygen-containing functional groups on the surface of the primer is higher, the surface wettability is the best, and the roughness is also relatively high. When the radiation energy reaches 360 mJ cm−2, radiation energy that is too high would reduce the adhesion performance of the UV primer on the surface of bamboo lumber. In addition, the gloss difference of the UV ink coatings between adjacent parameter samples is small, while the color difference is more obvious. The energy of UV radiation should be controlled in the range of 180∼240 mJ cm−2 in the actual production application.

UNTYING THE THREAD OF INNOVATION: CHALLENGES AND PROSPECTS FOR NIGERIA’S TEXTILE ARTS

Nigeria’s textile arts scene is a vibrant tapestry of creativity, rich cultural heritage, and untapped potential. Textile arts is one of the solutions to the development of any nation. Despite its significance, the production faces numerous challenges that hinder innovation and growth. This article explores the obstacles and opportunities for innovation in textile arts in Nigeria, examining the current state, challenges, and prospects for future development. The study adopts multiple methods of research design such as literature review, case studies, expert interviews and discussions, observational studies to gather enough data with content analysis, and qualitative methods to analyze the data. Some challenges include lack of modernization and technology, brain drain and skills gap, lack of adequate raw materials, etc. In contrast, the ideas for innovation include, the revitalization of Adire and batik training programs and workshops, digital printing and design, etc. This will eventually lead to innovation for the nation’s building helping the graduates to be self-employed and also employers of labour. Findings reveal that there are still opportunities for improvement in the sector if the right strategies are implemented. KEYWORDS: innovation, challenges, textile arts, prospects, textile industry.