Guang Xue Chen

Speedup Method for Paper-Based 3D Color Printing Based on STL File

Most paper-based 3D color printers are plagued by the problem of slow printing speed, which is caused by the double-sided coloration for A4 office paper during the printing process. In order to resolve this issue, we propose a new fast and reliable coloration algorithm using geometric information in STL file, given the existing slicing methods. During the entire process, the colored surface is determined by D value that represents the positive or negative slope of layer in the 3D model after slicing. Colored inks with corresponding permeability are used to print single-sided or double-sided to accelerate the printing speed. For the given 3D models, the efficiency of the speedup is discussed and qualitatively analyzed. The results show that the proposed algorithm can increase the printing speed of paper-based 3D color printers, based on the existing materials and apparatus, at a lower cost than the common approaches.

Preparation and Study of Ink-Jet Printing of Ag Based Conductive Ink on Paper

Compared with the lithography and traditional technology, ink-jet printing technology has huge advantages such as reducing costs, improving production efficiency and reducing environment damage. The silver nanoparticles conductive ink used as core material in ink-jet printing technology has been greatly developed. At present, the conductive inks for printed circuit usually has high sintering temperature, low adhesion, poor mechanical properties, high cost, which limit the further industrial application. In this paper, nano silver pulp was prepared through liquid phase reduction method, and a self-made protective agent ensured that the particle size distribution of silver particles is about 5nm. The above silver pulp was dispersed in the organic resin to get conductive ink with 20% (wt%) silver content. Under 170°Csintering, the electrical conductivity of the ink layer was 1.15×104S/m.

3D Printing of Topographic Map Based on UV Ink-Jet Printer

Traditional maps have the characteristics of high and low terrain, using the method of contour. Although contour map can express relief form, the stereo sense is not intuitive. In this paper, according to the characteristics of UV inkjet printer, the designed test pattern was printed, ink layer thickness of different colors was measured to establish a quantitative relationship between ink thickness and ink layers. The contour map of Taiwan was chosen, in graphics processing software, to extract the contour vector image according to its elevation. According to the relationship between ink thickness and ink layers, the corresponding relation table between the actual elevation and ink layers was established. Layered corresponding table was designed, according to the contour of layered principle. The experimental result shows that the color topographic map with stereoscopic effect can be obtained, through UV ink-jet printer.

Single Pulse Study of Electrochemical Discharge Machining of Metal Matrix Composites

Single pulse experiments were conducted to study electrochemical discharge machining (ECDM) of particulate reinforced metal matrix composites (MMCs) which are widely used in the packaging industry. This article reports the first phase of this study with an emphasis on the effects of pulse current on crater volume. The results showed that all the ECDM craters have a circular shape surrounded by a rim of re-solidified material. This indicates that ECDM craters were created by arc effect. The craters produced by both electrical discharge machining (EDM) and ECDM increased in volume with increasing peak current. However, within the range of currents studied, the craters formed by ECDM were always smaller than those produced by EDM alone under the same current. Moreover, the crater volume difference between EDM and ECDM did not change considerably with increasing current. This is considered to be due to an increase in ECDM current mainly enhances the arc energy and has little effect on the ECM action. Furthermore, the experiment results showed that the efficiency of the arc action in ECDM is reduced when the percent of reinforcement phase is increased.

Research and Manufacture of Nano-Silver Conductive Ink

Printing electronics technology promotes the application of conductive ink. In this paper, the manufacture of nano-sliver conductive ink is investigated. First, Spherical silver nano-particles were reduced from silver nitrate solution by liquid chemical reduction method, with hydrazine hydrate as reductant and PVP as surface-protection reagent. SEM was used to characterize the morphology of silver powders, and the mean particles size is 62.79 nm. Then, conductive ink was prepared with nano-silver particles made in this research as conductive fillers, polyurethane resin and acrylic resin as binders, and stearic acid as dispersant. In the last, the conductive ink was printed on the PCB substrate by screening printing. After the ink is dried, conductivity, abrasion resistance, and adhesion were tested. The experiment results shows that the order of sheet resistivity magnitude is 10-4Ω•m, the number of rubbing fastness is more than 6000, and the adhesion can be resisted repeatedly to tape tear.

Research on Gray Balance in Ink-Jet Printing Based on Paper Color Characteristic

The gray balance in color printing is the basis of accurate color reproduction. In essence, it reproduces accurate gray value by using color ink. In this paper, we choose three kinds of papers with different whiteness, use the same ink -jet printer and the same ink to print gray balance test charts and measure neutral gray blocks in order to draw the gray balance curves. Experimental result shows that the characteristic of gray balance curves obtained by this method are different from those obtained by traditional method. Especially in bright tone, the gray balance data gets a better adjustment, which can improve the exact color reproduction in ink-jet printing.

A New Method for Reproducing Oil Paintings Based on 3D Printing

This work aims at presenting a new method for reproducing oil paintings via 3D printing. We used a laser scanner to detect the surface morphology of an oil painting and found it was capable to print the stereo brushstrokes through layered printing after analyzing the UV ink thickness of type UJF-3024 ink-jet printer. Base on the 3D model we established, a slicing strategy was proposed for 3D printing. An experiment was conducted to validate feasibility of the method. Ultimately, the method has proven to be comparatively effective.

Preparation, Structure and Properties of High Performance Silver-Filled UV-Curable Polyurethane Acrylate Conductive Inks

In this paper, polyethylene glycol thioglycolate was prepared by esterfication. Spherical silver nanoparticles were formed from silver nitrate solution by liquid chemical reduction method with hydrazine hydrate as reducant. Based on the previous two steps, the nanoAg was absorbed by the polyethylene glycol thioglycolate trough the deposition. Metal nanoparticles were absorbed by polyethylene glycol thioglycolate with M-S bond to form polymer modified nanoparticle powder. The conductive inks were prepared using modified nanoparticles, other filler and laborator self-made water-borne polyurethane resin as the bonding material. Then the ink was coated on the PET film surface to mold. Catalyst, temperature and time effected esterfication. The esterfication rate was about 55% at 110°C for 3 hours. XRD indicated that the nanoAg prepared were cubic crystals, TEM showed that the size of modified nanoAg was less than 10nm. Metal nanoparticles with M-S bond effectively reduced the surface energy and had better compatibility with organic materials. Cross-cutting tests showed that adhesion between the ink and PET films was well and the conductive inks also showed good wet resistance and thermostability.

Research on the Color Correction Algorithm of Images Based on Histogram Matching

Different rendering conditions (e.g., changes in lighting conditions or atmospheric conditions, changes of the imaging system) often cause significant color differences between two images. In the prepress process, the brightness and hue between two images should be adjusted to be as similar as possible. Currently, we generally use image processing software such as PhotoShop to adjust the image manually, it’s complex and time consuming. In this paper, the color correction algorithm based on histogram matching was put forward and implemented. Only one image needed to be adjusted well previously as the reference image, and the mapping relationship was established on pixels between the histogram of the source images and the reference image, then the source images would have the histograms similar to that of the reference image, so that the images would have similar color characteristic and achieve image color correction finally. The experimental result showed that the realized color correction algorithm was effective, it could not only maintain the visual effect of images, but also eliminate the color differences between the reference image and the source images.

Effect of Paper Surface Characteristics on Dot Gain in Ink-Jet Printing

Four kinds of ink-jet papers with different surface characteristics are chosen in this paper, by the ink-jet proofing experiments, the influence of surface characteristics to dot gain is studied, and the law of dot gain with paper surface characteristics is discussed. During the experiment, surface properties including absorbency, gloss, roughness and whiteness are tested firstly; then, the standard wedge of GATF is printed on these papers in the same printing conditions; finally, the dot gain is tested by SpectroEye. After experimental data processing and analysis, dot gain curves of different ink-jet papers are concluded, the law of dot gain with ink-jet paper surface characteristics is summarized. The results show that dot gain is different in different paper, the evaluation of 3# is the best; dot gain is also different with different colors in the same paper, and it is serious in cyan but light in yellow; the biggest dot gain appears in different contrast with different colors, cyan appears near the 65% dot area. The result of this paper offers a certain theoretical reference and practical guidance to the selection, the research and development of ink-jet paper as well as the improvement of ink-jet qualities.