UV Inkjet Printing Research Articles

Effects of MDF Substrate Surface Coating Process on UV Inkjet Print Quality

The structural properties and whiteness of the substrate surface markedly effect printing quality and are closely related to the primer coating processes. Herein, four different roller coating schemes were applied on MDF surfaces to change their structural properties and color, and the whiteness, gloss, and roughness properties of the substrate surfaces were characterized for UV inkjet printing. Data analysis was conducted to explore the effects of these variables on the color reproduction, relative contrast, and printing gloss of the MDF substrates. The results showed that, according to CMYK, L*a*b* values and spectral reflectance data, the finishing of the MDF substrate with a 40 g/m2 layer of transparent primer combined with three layers of white primer at 20 g/m2 per roll coating layer had the best color reproduction effect for UV inkjet printing. Regarding the effects of relative contrast, the correlation with whiteness and glossiness was significant, while the correlation with glossiness was minor. The inkjet printing gloss value was positively correlated with substrate primer surface whiteness, while it was negatively correlated with roughness. When the surface whiteness of the substrate was relatively high, the roughness was lower and the printing effects were glossier. We sought to optimize the printing effects of all aspects of the MDF substrate by primer coating. The results of this work provide a feasible application method to improve printing quality and enhance the added value of low-quality boards, as well as to further expand the application of UV inkjet printing in the wood decoration market.

The artistic aesthetic and cultural value orientation of 3D printing

Abstract For the current artwork, 3D printing design simulation technology has the disadvantage of low clarity and poor effect, which cannot effectively describe the designer's work. To this end, this paper investigates the artistic aesthetic and cultural value orientation of 3D printing. First, the 3D digitization work of the oil painting was carried out by using the multi-baseline photogrammetry method in photogrammetry technology. Then the non-measurement digital camera was checked for internal orientation elements, the control panel was photographed, and the internal orientation elements of the camera were measured using the spatial backward rendezvous solution method. Next, the digital image acquisition of the oil painting is carried out, and finally, the photos are sequentially introduced into the Lens photo multi-baseline photogrammetry system to generate the color point cloud model of the oil painting after performing the steps of homonymous point selection null-three matching and beam leveling. In order to enhance the visualization effect, the color point cloud model was used to generate a digital model of the TIN irregular triangular network to realize the 3D digitization of oil painting art. The results of the study show that the thickness of each layer obtained by UV inkjet printing of five types of inks: yellow, green, blue, black, and white is about 11.19 μm, 12.71 μm, 7.91 μm, 9.47 μm, and 13.12 μm, respectively. 3D printing technology for positive impact on art design needs to be recognized and respected, and the better development of related technologies can make the advantages and advancement of the technology itself more fully embodied.

Utilization of Laboratory Papers with Non-Wood Fibres as Printing Substrates Observed Through the Maximum Ink Penetration Depth

The use of non-wood fibres for paper production could be one of the most environmentally friendly and economical alternatives. Reducing the consumption of wood pulp in paper and cardboard production by replacing wood pulp with alternative plant biomass could be a viable solution, as the amount of non-wood fibres in biomass is far from being exhausted. In this study, straw from the most commonly grown agricultural crops in Croatia was used as a source of non-wood fibres. Agricultural residues from wheat, barley and triticale were selected as a substitute for wood fibres for the production of laboratory papers with straw fibres. Under laboratory conditions, straw pulp was mixed with recycled wood pulp in a ratio of 30:70 to produce paper sheets that can be printed with different printing techniques. Regardless of the printing technique used, it is desirable that the prints contain a high-quality reproduction of the image and text on the surface of the paper and that the ink does not penetrate completely through the substrate. In this context, this study observed the use of laboratory-made papers with non-wood fibres as the printing substrate by analysing the maximum depth of ink penetration into the printing substrate obtained with two printing techniques - a modern one (digital UV inkjet) and a very high quality conventional one (gravure). It was found that the gravure printing favoured a greater penetration of the UV ink into the substrate with the addition of straw pulp compared to the digital printing technique. However, this is a consequence of the printing technique, as similar ink penetration was also observed on the laboratory substrate made only from recycled fibres. Compared to commercial papers, the ink penetration is slightly higher into the laboratory made printing substrates. It is interesting to note that the printing substrate with the addition of 30% triticale pulp has the lowest ink penetration, especially in multicolour prints produced with the digital UV inkjet printing technique.

Use and analysis of UV varnish printed braille information on commercial packaging products

This paper investigates the possibility of reproducing Braille by UV ink-jet printing on self-adhesive labels, previously printed by flexo printing technology. The aim was to determine whether it is possible to reproduce Braille, the degree of quality of created Braille dots (cells), the legibility of Braille text, and how many layers of varnish are necessary for quality reproduction. The Braille letter was applied to the previously printed label (design) using 8, 10, 12, 14 and 16 layers of varnish. It has been found that it is possible to reproduce a quality and legible Braille. With the increase in the number of layers, the assessment of legibility and quality of reproduction by the respondents also increased. Samples reproduced with 12 layers of varnish received a very good grade of legibility and good grade for quality of Braille. Samples reproduced with 8 and 10 layers received bad grades for legibility, and even worse for quality, while samples with a higher number of layers of varnish, 14 and 16, received even better grades. The threshold for quality reproduction would therefore be the use of 12 layers of varnish, where a good ratio of workmanship and economy is obtained.

Morfološke in dimenzijske lastnosti nemodificirane in modificirane brajice izdelane z UV-kapljičnim tiskom

Morfološke in dimenzijske lastnosti nemodificirane in modificirane brajice izdelane z UV-kapljičnim tiskom

Photogrammetry-Based 3D Printing Reproduction Method for Oil Paintings

This paper proposes a new oil painting reproduction method using 3D printing to compensate for the deficiencies of the existing methods. First, 3D reconstruction of oil paintings is completed by photogrammetry; the oil painting color and the 3D geometric information are recovered better by acquiring several sets of orthophotomaps, and modeling accuracy is ensured with a control mesh or by flattening. Next, the contours and hypsometric tints of the 3D model for oil paintings are generated using contour tracing algorithm, and the image segmentation of renderings is completed using RGB image segmentation algorithm, with the layered section extracted from each layer and the 3D geometric information converted into 2D plane information. Finally, the 3D models of oil paintings are presented through UV inkjet printing with images superimposed layer upon layer, and stereoscopic reproduction of oil paintings is completed based on the orthophotomaps printed from the 3D models.

Effects of Paper on 3D Printing Quality in UV Ink-Jet Printing

The experiment studied effects of paper on the height and glossiness of UV ink-jet 3D printing. The results showed that there all existed penetrations between the 1st ink layer and three kinds of paper, the bigger the roughness and bulk of paper were, the larger the penetration was, and penetration between the 1st ink and paper was obviously larger than that between two ink layers. Penetration between two ink layers was stable, almost not affected by paper. The bigger the roughness and bulk of paper were, the smaller the glossiness of ink layer was. There appeared directional ink strips on ink layer on three kinds of paper, beginning from the 3rd ink layer, there also appeared ink pits on ink layer on paper whose roughness and bulk were the biggest, which showed printer precision was also an important factor for the glossiness, apart from paper. Thus, the tight and smooth paper should be selected in UV ink-jet 3D printing. Before printing, pretreatment should be done to exclude the influence of the 1st ink layer and the ink strips.

Surface Modification Methods to Improve UV Inkjet Printing Performance of Ceramic

Using UV inkjet printing can achieve three-dimensional printing of ceramic materials, but there is low ink adhesion, easy to fall off and other issues, surface coated modification to high smoothness ceramic materials can solve the above problems [1]. In this study, the silane coupling agent, adhesive, resin and other raw materials prepared for transparent coating, which applied to the surface of the ceramics. The impact of process parameters and coating formulation on the UV print quality of the ceramic base was systematic analyzed, the result shows that the volume concentration of 10% KH550 silane coupling agent as primer, and using 20wt% 102 multipurpose plastic glue for surface coating, better ink adhesion and printing quality can be obtained.

A Study on Color Variance of IMR between PET Coated and Uncoated White Ink by UV Inkjet

IMR can print out excellent textures and effects on irregular surfaces. Many products decorated by IMR are protected from water and fading, and these kinds of decorations strongly increase beauty, desirability and value of the objects. Therefore, this research is to investigate the potential use of combining IMR with UV inkjet printing and to compare color variance of IMR between PET coated and uncoated white ink. Study results show that the SIDs of PET with white ink is higher about 0.15 to 0.2 than the PET without white ink. The SIDs of PET without white ink will decrease and the SIDs of the PET with white ink will increase when transferred. The PC of PET without white ink is about 10 to 15 higher than the PET with white ink. After transferred, the Color Gamut became smaller than before. Especially for the PET without white ink, its color differences △E can reach 40. In addition, the color gamut became smaller when transferred.

The Study on Color Quality Attributes of IMR with PET on White Ink by UV Inkjet

The In-Mold Roller is a revolutionary printing process by which objects are 3D decorated. Products decorated by In-Mold Roller are waterproof and protected from fading. What’s more, these kinds of decorations strongly increase the beauty, desirability and value of the objects. The In-Mold Roller is now using either of gravure printing and screen printing to print PET film. However, there are some problems with these two techniques. This research is to investigate potential usages of combining In-Mold Roller with digital UV inkjet printing in 3D decoration, e.g. in personalized printing services. Study results found that when the coverage and the resolution of inkjet printing become higher, the SIDs will become higher as well. When transferred to ABS, SIDs in each combination will increase. Each combination of inkjet conditions, with the isolation of white ink, color differences are less variant. TVIs of white ink decrease 30% to 40% halftone and display in “M” type. In print contrast, C and K colors of each combination are better than M and Y colors. After transferred into print contrast, each combination of PC will be higher about 2 to5. When transferred to ABS, color variances of each combination are not huge, and color differences are about 3to5.

Properties and printability of compression moulded recycled polyethylene

The goal of the research was the determination of the properties and printability of polymeric materials made from the recycled polymers, low-density polyethylene (LDPE) and high-density polyethylene (HDPE). From the primary (virgin) polymers and secondary (recycled) polymers that were obtained from the separately collected fractions of waste packaging, compression moulded plates were produced. The tensile properties of 1mm and 2mm thin plates were correlated with some structural characteristics: melting point, melting enthalpy and crystallinity degree. It was determined that the recycling process changes the melting behaviour, lowers the crystallinity and to some extent influences the tensile properties of plates. LDPE and HDPE compression moulded plates were printed with the UV inks on the large format digital UV inkjet printer Océ Arizona. To investigate the printability of plates made from the recycled materials some of their surface properties were determined. Higher optical density, area of ink coverage and dot gain of the printed HDPE plates compared to the LDPE plates are the consequence of higher roughness, higher surface energy with prevailing part of the polar component. By adding 4% of coloured master batch to the recycled polymer at moulding, the uniformity of colour is improved leading to the higher print quality. The results have shown that the digital UV inkjet printing technique could be applied for printing recycled polyethylene plastic materials, used for disposable low cost packaging products.

Research on the Relationship between Properties of Printing Paper and UV Inkjet Printing Quality

As an environmental printing method, UV inkjet printing is becoming a hot research topic and has great prospects for development. The purpose of this paper was to integrate theory with practice to analyze the relationship between printing paper and UV inkjet printing quality. This could make press worker determinate rationally printing paper and improve the printing quality. In this paper, kinds of paper surface characteristic (including whiteness, glossiness, roughness, Permeability, absorbent) were measured. Printing tone and color reproduction results of these papers were experimented. Different prints parameters were tested with saturation, hue error, gray scale and coloration efficiency. Data of the paper parameters and prints parameters were calculated separately by Principal Components Analysis (PCA) with software. Then, the equation between paper parameters and paper quality synthetic value was obtained on the basis of the tested data. The equation between prints parameters and prints quality synthetic value was obtained in the same way. Linear regression was used to find the correlation between line combination of print quality synthetic value(y-axis) and paper quality synthetic value(x-axis). Paper printability prediction equation is derived according to the curve. It was shown that the results can provide valuable reference for the evaluation of the quality of printing papers and improving color reproduction, and can be used as one of the basis to guide the production.

Color Gamut of UV Wide-Format Inkjet Printing on Special Substrates

UV Inkjet Printing has demonstrated extraordinary potential in printing technology around the globe in recent years. Other than its environment-friendly trait, UV Inkjet Printing can also be applied to various printing materials due to its wide range of application. Comparing to the low-price competition invoked by paper-based printing, it achieves high added-value results from its output. While international market’s perspective on inkjet printing remains positive, most printing press in Taiwan still have doubts for the technology. In recent years, there has been a considerable growth in importing UV Width Inkjet printers in Taiwan domestically. However, working personnel in Taiwan are inexperienced in dealing with new equipment and wider selection of printing materials, therefore the issue of printers adapting to their diverse printing materials. This study will examine the five combinations of UV printer and printing materials that are common in Taiwan (brands of printers, serial number of the sprinkler head, and brands of printing ink) and three specific high-value printing substrates (glass, acrylic and melamine plywood). Through the printing experiment, the color gamut of printing materials will be re-examined. The goal of the study is to establish a standard for UV printing’s application in decoration materials, so as to provide reference for future development.

The Study on Color Print Quality Attributes of In-Mold Roller Using Digital Inkjet Printing

The In-Mold Roller is a revolutionary printing process by which objects are 3D decorated. The products decorated by In-Mold Roller are protected from water and fading. These kinds of decorations strongly increase the beauty, desirability and value of the objects. The In-Mold Roller is now using either of gravure printing and screen printing to print PET film. However, there are some problems with these two techniques. This research is to investigate the potential use of combining In-Mold Roller with digital inkjet printing in 3D decoration, e.g. in personalized printing services. The study results found show that digital inkjet printing to the PET film and then transfer to the ABS, the solid ink densities (SIDs) of primaries would increase. The tone values increases (TVIs) from highlight and middle (around 0~60%) were generally higher than those in shadows. The shapes and sizes of color gamut were also varied according to different kinds of digital UV inkjet printing processes. Moreover, after transferred, the color gamut became smaller.

The Study of the Influence of Photoinitiators on Curing Rate in UV System under Different Oxygen Atmosphere

The UV system contains prepolymer, monomer and photoinitiator has been broadly used in printing area. UV-curable inkjet ink with its environmental protection, energy-saving, good printing quality and high efficiency has become the most concerned topic and has a good development prospects. The use of UV ink-jet printing ink in ink-jet digital printing is the main development trend of digital printing currently and a period of time in future. Curing rate is one of the most important performance parameters of the UV system which is greatly affected by prepolymer, monomer and photo-initiator, besides that, the oxygen atmosphere is another principal element. In order to investigate the influence of different oxygen atmosphere on the curing reaction, we designed and made a UV curing device with varied degree of oxygen atmosphere to study the effect of photo-initiator species and content on the systems curing rate under different oxygen atmosphere condition.

Improvement of image quality in single pass UV inkjet printing

This report introduces factors to improve image quality obtained by single pass inkjet printing with UV ink. As reported at NIP24, this study is made with 600 dpi single pass inkjet printheads, capable of single pass printing at 847 mm/s in 108 mm print swath. In the former study, authors concluded that image quality could be sharper by higher pass speed in case of single pass inkjet printing, since amount of ink flow on a media surface before curing can be restricted. However, it was revealed that fast printing speed could suffer image quality with unevenness of image surface created with thick ink layer. In order to solve the problem, approaches are made from both ink and printhead properties. Firstly, static surface tension of UV ink is lowered from 30 to 22-25 mN/m. It is expected to maintain enough dot gain with smaller drop volume, which makes ink layer thinner. Also, color density of ink has to be enhanced to keep equivalent color range with thinner layer. Secondly, printhead is modified in terms of optimum drop volume range from 5 – 19 to 4 – 12 pl for modified ink. Also, drop placement accuracy is improved by increasing drop velocity. As a result, thickness of ink layer is reduced from 12.7 microns to less than 9.6 microns on a gloss coat media. As a result, appearance of color images are much improved. It is achieved UV ink named AGORA G1 developed by Agfa Graphics.

Alternative UV Radiometry and Process Verification for UV Ink Jet Printing

Alternative UV Radiometry and Process Verification for UV Ink Jet Printing

Did you miss the IMI Europe 11th Annual Ink Jet Printing Conference or the 1st European UV Ink Jet Printing Conference?

Did you miss the IMI Europe 11th Annual Ink Jet Printing Conference or the 1st European UV Ink Jet Printing Conference?