In digital textile printing process, various factors affect printing quality on fabric. One of these factors is pre-treatment process. If this process is carried out to control chemical interactions between dyes and fabrics strictly, proper pretreatment solution must be prepared depending on fabric types. Otherwise, high printing quality never realizes. Thus, in our previous work, [1] we focused on pre-treatment process and investigated the impact on coloring characteristics such as optical density and ink penetration on fabric in changing thickener which was one of the key materials in pre-treatment solution to realize high printing quality. As a result, we demonstrated that using two thickeners having different chemical structures from each other was much effective to adjust above coloring characteristics on fabric depending on required printing quality. However, in this previous work, we couldn't investigate and discuss whether controlling other parameters of thickener enabled us to alter coloring characteristics on fabric flexibly. Thus, in this paper, we focused on molecular weight of thickener as a parameter to affect printing quality on fabric and investigated whether changing molecular weight was effective to fine-tune coloring characteristics on fabric or not.

Direct to garment printing is expanding its presence on the textile market today due to the markets search for sustainability, print on demand, fast response, mass customization and inventory reduction. While this type of printing in terms of quality may be enough for the promotional market, brands are still struggling with both quality and performance of the DTG prints on natural fibers, especially on dark colors.<br/> This paper is focused on research of print quality of the digital direct to garment printing based on the fabric hairiness and pretreatment level, which are the main obstacles for quality and sustainable printing. <br/> Open End and Ring spun yarn types of the same count 30/1 Ne are chosen. They are knitted with the same knitting parameters (stitch length and gauge) and dyed on the same dying batch. Hairiness values coming from the yarn production and fabric dying process are respectively compared. Swatches with different opacity level (25%- 50%-75% and 100%) of CMYK are printed on all fabrics with and without White underbase. In addition the effect of 3 different amounts of pretreatment are added for evaluation. The research gives the comparison of values of L lightness value (for dark colored fabrics) and S saturation value on 10 different fabric types. <br/> The result showed that wet pretreatment processing on fabric treated with enzyme gives the best results based on L values on ring spun fabrics on both enzyme treated and untreated fabrics. Important finding is that there is a need for pretreatment optimization of Open Endfabrics while ring fabrics gave the same result on 3 different pretreatment amounts. This conclusion is valid for dark fabrics only, while there was found no significant difference for white fabrics both on ring spun and open end. <br/> The brushed fabric (which had the highest hairiness level) gave the poorest printing results (based on L and S values measurements) showing the negative effect of hairiness value to print quality. <br/>

Digital textile printing (DTP) is fast, flexible, and relatively inexpensive for sample printing, and can be applied quickly in response to consumer demand. The aim of this two-stage research was to analyze the potential of DTP to replace traditional screen printing for a specific textile product. In Stage One, an optimal DTP workflow was established. The workflow included determination of the colorant and substrate combination, color calibration, CAD file, and the necessity of pretreatment. In Stage Two, a visual assessment instrument and protocol were established to evaluate the acceptance of replicated ink-jet printed fabric. The visual assessment and protocol were designed to evaluate the acceptance of the ink-jet printed sample to fully replicate the screen-printed sample via seven measured aspects. These seven aspects include: perceived color difference, lightness difference, overall color, scale, line quality, visual texture, and overall appearance. Data gathered from the visual assessment was then analyzed and compared using SPSS statistics software. The results indicate that DTP demonstrates a significant potential alternative for traditional screen printing.

In industrial printing, digital printing which can handle a large variety of substrates has been demanded. Digital printing employing inkjet system using UV ink has been adopted to print images on variations of substrates, but UV-ink contains Volatile organic compounds (VOC). Aqueous-ink is relatively VOC-less but can't handle a variety of substrates. We solved these problems by developing new aqueous resin ink. The aqueous resin ink has high durability on leathers and the compatibility to variations of substrates.

3D printed electronics (3DPE) is an enabling technology that has the potential to allow for the advanced track and traceability of every 3D or additively manufactured (AM) part; enable communication and sensing by an individual part; and remove geometrical limitations for electrically active devices which can directly take on the final product form factor. Additionally, AE solutions attempt to allow for faster prototyping for conventional circuit designs. HP's Multi Jet Fusion (MJF) technology is a powder-based 3D printing technology that enables the production of high mechanical performance polymer parts at high speeds and reduced costs. At HP Labs, the advanced capabilities of the MJF platform have been researched. We have developed a process for 3D printed electronics. This allows an ink-jettable conductive agent (CA) to be utilized with the MJF process to build conductive traces, vias, and contacts anywhere within or on a printed part during the 3D printing process.

As the FFF/FDM 3D fabrication process becomes more accepted and popular in industry, the demand for products with higher anti-abrasion capability, higher durability as well as the ability to withstand higher temperature is growing fast. The materials for this type of product are known as "super engineering plastic" and materials such as PEEK and TPI are the examples.<br/> Due to the high temperature requirements, the existing hotends which are made for lower temperature materials like PLA and ABS are not capable to handle the material. A revolutionary new concept hotend for high-temperature usage in the range of 300 °C to 500 °C has been developed specifically designed for the super engineering plastic materials.<br/> The new hotend is compact in size and the thermal capacity is small accordingly compared with the conventional units, but it can follow the precise temperature requirements and fine adjustments as needed. Unlike the others, this hotend does not need a large cooling system (either forced air or liquid coolant) to prevent the heat creep on the cool end of the extruder. It is more energy efficient and eco-friendly as it heats when it is needed. Also, thanks to the size and weight, multi-nozzle device will be feasible in the near future.<br/> With the new design improvement and ability to monitorcontrol the hotend temperature more accurately, it is much more clogging-resistant of filament material than existing or even our own previous year's hotend.

Ceramic additive layer manufacture employs a range of different technologies including ceramic paste extrusion, powder/ binder jet and UV and daylight cure ceramic loaded resins. Each of these technologies has its own set of advantages and disadvantages. This paper investigates the possibilities of using a robot multi-axis system to enhance the capabilities of a ceramic paste extrusion process.

The Woodburytype is a 19th century photomechanical technique, producing high-quality continuous-tone prints that use a mixture of pigment and gelatine as a relief print, in which the variation in height of the print produces the tone and contrast. We propose a phenomenological optical model for the process based on Kubelka-Munk theory that considers the ink formulation, the print height and the substrate surface in order to provide the ideal combination of printing depth and contrast.

Hydrogels are considered as appropriate scaffold materials for cell encapsulation. This is due to their high water binding capacity similar to the native extracellular matrix. However, the equilibrium degree of swelling of simple hydrogels is related to the cross-linking degree of the hydrogels and thereby not freely adjustable. We decoupled the correlation of equilibrium degree of swelling and cross-linking density by chemical modification of the biopolymer gelatin and sophisticated hydrogel formulations. These formulations contained different amounts of chemical modified glycosaminoglycans, genuine components of native extracellular matrix of cartilage. We created glycosaminoglycan-graded hydrogels by layer-wise dispensing three hydrogel precursor solutions on top of each other. We investigated the viability of the encapsulated chondrocytes 28 days after printing and evaluated the production of newly synthesized extracellular matrix.