Enhancing digital ink-jet printing patterns quality through controlling the crystallinity of cotton fibers

Cotton fibers have a high crystallinity, which makes a large number of reactive hydroxyl groups blocked and therefore affects the ink-jet printing performance of reactive dyes on cotton fabrics. In this work, the alkali treatment was employed to adjust the structure of cotton fibers. The crystallinity of treated cotton fibers reduced from 73.9–58.5%, and the breaking strength did not decrease compared with original cotton fiber. Thus, the accessible reactive hydroxyl groups and the wettability were enhanced for treated cotton fibers, which promoted the penetration of inks into the fibers. The optimal K/S value of 23.47 was achieved for treated cotton fabrics which was higher than that of untreated cotton fabrics (17.15). Meanwhile, the printed fabrics displayed good washing fastness, rubbing fastness and glossiness. This work provides an effective way for improving the utilization of dye solution and producing high-quality cotton fabric digital printing products.

Off-The-Shelf Stylus: Using XR Devices for Handwriting and Sketching on Physically Aligned Virtual Surfaces

This article introduces the Off-The-Shelf Stylus (OTSS), a framework for 2D interaction (in 3D) as well as for handwriting and sketching with digital pen, ink, and paper on physically aligned virtual surfaces in Virtual, Augmented, and Mixed Reality (VR, AR, MR: XR for short). OTSS supports self-made XR styluses based on consumer-grade six-degrees-of-freedom XR controllers and commercially available styluses. The framework provides separate modules for three basic but vital features: 1) The stylus module provides stylus construction and calibration features. 2) The surface module provides surface calibration and visual feedback features for virtual-physical 2D surface alignment using our so-called 3ViSuAl procedure, and surface interaction features. 3) The evaluation suite provides a comprehensive test bed combining technical measurements for precision, accuracy, and latency with extensive usability evaluations including handwriting and sketching tasks based on established visuomotor, graphomotor, and handwriting research. The framework’s development is accompanied by an extensive open source reference implementation targeting the Unity game engine using an Oculus Rift S headset and Oculus Touch controllers. The development compares three low-cost and low-tech options to equip controllers with a tip and includes a web browser-based surface providing support for interacting, handwriting, and sketching. The evaluation of the reference implementation based on the OTSS framework identified an average stylus precision of 0.98 mm (SD = 0.54 mm) and an average surface accuracy of 0.60 mm (SD = 0.32 mm) in a seated VR environment. The time for displaying the stylus movement as digital ink on the web browser surface in VR was 79.40 ms on average (SD = 23.26 ms), including the physical controller’s motion-to-photon latency visualized by its virtual representation (M = 42.57 ms, SD = 15.70 ms). The usability evaluation (N = 10) revealed a low task load, high usability, and high user experience. Participants successfully reproduced given shapes and created legible handwriting, indicating that the OTSS and it’s reference implementation is ready for everyday use. We provide source code access to our implementation, including stylus and surface calibration and surface interaction features, making it easy to reuse, extend, adapt and/or replicate previous results (https://go.uniwue.de/hci-otss).

Gamified geo-challenges for immersive learning

<p>Project LIVE (<em>Learning through Immersive Virtual Environments</em>) is a cross-disciplinary initiative at the University of South Australia to embed immersive virtual and mixed reality experiences across the breadth of our STEM teaching program. In Earth and Environmental Science, the Project LIVE team has recently created a series of gamified geo-challenges and virtual tours of instructive field sites for use in undergraduate teaching, to both supplement and enhance traditional field experiences. This presentation will demonstrate our flagship geo-challenge developed for the Hallett Cove Geological Heritage Site in Adelaide, South Australia. Entitled <em>Beyond the Ice</em>, it incorporates several complementary elements including an immersive VR experience, web-based geotour, iOS and Android mobile learning game and 360 street view walking trail, all of which are freely available at <em>https://www.projectlive.org.au/beyond-the-ice</em>. The interactive VR quest challenges students to identify fossils with a virtual hand lens, measure glacial striations with a compass, and draw the outlines of rock folds and sedimentary layers that shape the landscape with digital ink. Students are also accompanied by the encyclopaedic ‘VT’ – a virtual robot guide with a geological memory spanning 600 million years – and can take part in quizzes, collect 3D pet rocks, and even uncover hidden ‘Easter eggs’ on their journey of scientific discovery. The uptake and impact of our geo-challenges across both undergraduate student cohorts and STEM outreach audiences will be discussed, along with further geoscience and community engagement opportunities currently being explored.</p>

Influence of primers on the optical characteristics of ink-jet imprints

The quality of ink-jet printing depends to a large extent on the technical characteristics of the selected equipment and the surface properties of the printed substrates. It is known that for digital printing it is necessary to use expensive paper with a special coating that determines the degree of gloss of the surface. Therefore, ordinary offset papers before ink-jet printing are covered with primers that ensure good fixation of pigment ink or dye on paper, a wide field of color coverage, characteristic gloss, which generally contribute to high quality of imprints. As you can see, the type of the substrate and the state of its surface has a very great influence on the quality of the imprints. Result of the research, it has been confirmed that not only expensive paper of a special purpose can be used for a drop ink-jet digital printing. High-quality color imprints can also be obtained on ordinary offset and coated paper, coated before printing with special primers based on interpolymeric complexes of polyvinyl alcohol, which will provide sufficient optical density, contrast of images, and expand the possibilities of digital ink-jet printing.

Formulation of a graft polymer-containing aqueous yellow ceramic ink for digital ink-jet printing

Environmentally friendly aqueous ceramic ink which contains graft polymer as a surfactant was synthesized for ink-jet printing and exhibited excellent dispersion stability and ink-jet printability.