Papers by Author: Wen Juan Gu

Abstract: A defect feature extraction algorithm which depends on the separation and subtraction of color image and mathematical morphology is proposed in this paper, based on the defects in trademark printing processes, such as smudges, pin holes, misprints, misting etc. The difference images of each monochrome are operated with morphology methods and then the defect information of high precision printing processes in colorful trademark, such as shape, boundary contour, quantity, size and location etc, are extracted and recognized with suitable structure elements. The defect extraction algorithm is programmed and run by MATLAB and the results validated the high speed and precision of the algorithm about extracting some kinds of defect information in color trademark printing processes. The algorithm has met the real-time requirements of defect feature extraction in trademark printing processes. This research laid a theoretical foundation for researching and developing the color trademark quality detection system.

Abstract: The penetration of ink into the paper affects the final appearance of printing and the amount of ink usage. The main aim of this experiment was to investigate the efficiency of coating speed on surface properties and ink penetration and to characterize the penetration depth through quantitative analysis by laser scanning confocal microscope (LSCM). The results indicated that the surface properties of coated paper could be adjusted and improved by increasing the coating speed. With the increasing of coating speed, ink penetration depth declined and ink penetration uniformity increased. It could be concluded that the coated paper with high coating speed compared with low coating speed resulted in lower ink usage and better printability on the condition of same print density.

Abstract: The protecting of concrete, which consists of coating a chemical substance onto concrete’s surface, has been applied to architectural conservation. There is increasing interest in studying materials for concrete which can reduce the infiltration of water and salt solutions and rehabilitate and extend its service life. Silicon compounds are frequently used as a base for commercial protecting paint due to their hydrophobicity and penetrability. In this study, concrete was coated with paste-like emulsion impregnant. The factors that impact the waterproofing performance of the impregnant were investigated including the emulsifier amount, the penetration depth and the contact time. The capability of the impregnant was shown by the contact angle and the weight percent gain. The waterproofing performance of the concrete was increased after the coated with the so prepared impregnant.

Abstract: A new kind of microsphere filler was synthesized with octyltrimethoxysilane (WD13) and tetraethoxysilane (TEOS) by sol-gel method. The morphology of the filler was measured by TEM. The so synthesized spheres were added into the silicone rubber. Both the strain-stress and the water contact angle of the silicone rubber were researched. The results showed that both the mechanical property and the hydrophobic performance of the composite were improved compared with the blank specimen. The possible strengthen mechanism of the filler was discussed. The neotype silica sphere researched in this paper could react with the silicone rubber chains which perfects the vulcanization of the silicone rubber. This kind of sphere filler exhibits many merits for usage as filler.

Abstract: A neotype of silica microspheres were synthesized with chloropropyltrimethoxysilane (WD30) and tetraethoxysilane (TEOS) by sol-gel method. And the thermal properties of the filler both in nitrogen and in air condition were studied by means of thermogravimetric analysis. The morphology of the filler was measured by TEM. The so synthesized spheres were added into the silicone rubber whose mechanical strength was increased greatly. The molecular structure of the filler and the silicone rubber were characterized by FTIR. The possible strengthen mechanism of the filler was discussed. The neotype silica sphere researched in this paper could react with the PDMS chains which perfects the vulcanization of the silicone rubber. This kind of silica sphere exhibits many merits for usage as filler.

Abstract: What happens in the paper surface about ink absorption is of great important for appearance of final printing. The aim of this experiment was to investigate the influence of printing pressure and printing speed on ink layer thickness transferred onto coated paper through quantitative analysis by laser scanning confocal microscope (LSCM). Meanwhile, the influence of printing pressure and printing speed on print density and print gloss were obtained. The results implied that higher printing pressure resulted in higher ink layer thickness, print density and print gloss when printing pressure is less than 700N, but higher printing speed resulted in lower ink layer thickness, print density and print gloss when printing pressure is constant. It could be concluded that the coated paper with high printing speed compared with low printing speed resulted in lower ink absorption, lower print density, lower print gloss and worse printability on the condition of same printing pressure.

Abstract: The objective of this experiment was to investigate the influence of coating solid on surface properties and ink penetration and to characterize the penetration depth through quantitative analysis by laser scanning confocal microscope (LSCM). Fluorescent ink was used to observe and characterize ink penetration and distribution by LSCM. The results implied that the surface properties of coated paper could be adjusted and improved by increasing the coating solid. With the increasing of coating solid, ink penetration depth declined and ink penetration uniformity increased. It could be concluded that the coated paper with high coating solid compared with low coating solid resulted in lower ink usage and better printability on the condition of same print density.

Abstract: Development of green economy is the only way to relieve the restriction of resource, which is the effective and important way to improve economical benefit radically. Only in this way can continuable development be achieved. The research on pollution in printing industry was reported in this paper. The general pollutant such as solvents, exhaust gas, ink, and etc were summarized. The existing methods, measures and technologies which could solve or relieve the pollution of the printing industry on the environment were brought forward. The suggestions were advanced from country, enterprise, individual to science development aspects. The prospect would be fine with the efforts of the government, enterprise and human being.

Abstract: A new kind of silica microspheres were first synthesized with chloropropyltrimethoxysilane (WD30) and tetraethoxysilane (TEOS) by sol-gel method. And hybrid membrane was prepared by incorporating the as prepared filler into polydimethylsiloxane (PDMS). The IR, swelling density(Dsw) and mechanical properties of these composites membranes were studied by means of IR analysis and tensile testing. The experimental results showed that both mechanical properties of these composites were significantly improved by using the as-synthesized filler. The filler synthesized in this research not only increased the volume and reduce the cost of HPDMS, but also reacted with the PDMS. The vulcanztion density was increasedwith the interaction between the filler and the PDMS chains. This new kind of silica microspheres is an effective reinforcement filler for PDMS composite.

Abstract: The protecting of concrete, which consists of coating a chemical substance onto concrete’s surface, has been applied to architectural conservation. There is increasing interest in studying materials for concrete which can reduce the infiltration of water and salt solutions and rehabilitate and extend its service life. Silicon compounds are frequently used as a base for commercial protecting paint due to their hydrophobicity and penetrability. However, the stability of the impregnant emulsion is affected by many factors. The effect of three main factors such as component, pH, and emulsifier were studied in this paper. The stability of the impregnant decreased with the increase of pH. And the mixed emulsifier and 4～6% amount of emulsifier would be optical for the stability of the system and maintain the activity at the same time.