Applied Mechanics and Materials Vol. 469

Abstract: The water-based gravure ink does not contain volatile organic solvent, which is an environmentally friendly ink. But slow drying is a bottleneck of water-based gravure ink in use. Proposed the water in Water-based gravure ink reacts with temperature control microcapsule drying agent when heated in drying box of gravure printing machine to increase the ink drying speed. Designed preparation purification and drying methodthe of calcium oxide microcapsules, which surface is coated with hydrophobic compound and surfactant. The coating layer of Water-based gravure ink drying agent has good water resistance below 60°C, which will drop from the surface of the calcium oxide in the process of temperature continues to rise. Use the rheometer to test the rheology of water-based gravure ink contain microcapsule drying agent, characterization of the drying effect of the microcapsule drying agent based on the change in viscosity of the ink. Experimental results show that, the excitation temperature of the drying agent is 40°C. The Prepared temperature control microcapsule drying agent can effectively improve the drying speed of the water-based gravure printing ink.

Abstract: In order to fulfill the demand of fine circuit board, a UV-curable conductive ink was prepared, and the factors affect conductivity of ink was studied. Different UV conductive paste was prepared with different kinds of conductive material to research the influence of conductive material on the conductivity of paste. Change the variety of photoinitiator to prepare UV-curable conductive ink, and the effect of photoinitiator on the conductivity of ink was also studied. The results indicated that the variety of conductive material has a great influence on the conductivity of UV-curable ink. The ink, which prepared with flaky and spherical silver powder, has the best conductive property. Whats more, the conductivity of UV-curable ink is different with the change of photoinitiator, which would lead different cross-linking reaction after curing.

Abstract: Fluorescent ink can be applied not only in anti-fake packaging products, can also be used on other field to present a special artistic effect. The samples of fluorescent inkjet ink were prepared by changing the type of solvent, the excitation and emission wavelengthexcitation and emission intension were measured,and fluorescent quantum yield were calculated. The result shows Solvent has large effect on the luminescent intensity and fluorescent quantum yield of fluorescent material, and the optimal formula of solvent is Ethyl Acetate: Propylene Glycol Monomethyl Ether: Acetone=0.00:0.50:0.49.

Abstract: 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.

Abstract: In order to improve the anti-friction performance of water-based flexographic ink, we made up different kinds of water-base flexographic ink by changing the kinds of film-forming resin or adding different kinds of friction resistant additives, and then evaluated the friction resistant performance of the ink by the rate of density decay. According to analysis the influencing factors of the anti-friction performance of ink, aiming at improving the cohesion of molecular systems and smooth degree of membrane surface, and reducing the friction coefficient as well. The result shows that different molecular structure of film-forming resin ink will cause different cohesion of molecules system in ink, which impacts the ink friction performance. Adding appropriate anti-friction performance additives can improve ink cohesion of molecular system, and improve the ink anti-friction performance as well.

Abstract: UV-LED inkjet ink is a promising environmental ink which has advantages as higher reaction speed, higher efficiency and energy saving, better environmental protection, its research and development can contribute to realizing green printing and its important for food packing security. Monomer is the important component of the UV-LED ink, in order to investigate the impact of monomer on dispersivity of UV-LED inkjet ink, seven kinds of monomers were chosen to prepare cyan color paste respectively and test their particle size and distribution. Then the ratio of co-monomers was achieved by formulation experiment to obtain the best dispersivity. In order to improve the performance of the UV-LED inkjet ink, different monomers were used to make ink samples separately, viscosity, surface tension, curing rate of the ink and flexibility and adhesion were tested. In the end, the ratio of co-monomers was achieved by formulation experiment to obtain the best overall performance. The results show that the monomer has a significant influence on the dispersion and curing rate of the UV-LED inkjet ink, but also has a great impact on film-forming properties of the ink after UV-LED curing.

Abstract: Edible inkjet ink is a new water-based green ink, all the raw materials are in line with food hygiene standards, it has the characteristics of edible, safe, environmentally friendly and its suiTab.for food packaging printing. In order to obtain good performance and printing quality of edible inkjet ink, food-grade raw materials were used to prepare inkjet ink. Then the formula was optimized according to the effect on droplet state of ink viscosity and surface tension. In the end, droplet state and printing quality of prepared ink was tested. The results show that the prepared edible inkjet ink has good droplet state and printing quality.

Abstract: Tetra-(4,4-dimethyl-phenyl) dithiolene nickel complex was synthesized by sulfuration with P₂S₅ and nickel complexs using bis-(4,4-dimethyl-phenyl) ethanedione as raw material. The structure of dithiolene nickel complexes was characterized by melting point, IR and ¹HNMR. The maximum absorption spectra of this dithiolene nickel complexes in different solvent was measured by Ultraviolet-Visible-near Infrared Spectrum, and the photo stability and thermal stability were discussed. The results showed that this new method was used to synthesis bis-(4,4-dimethyl-phenyl) ethanedione, which greatly reduces the synthesis time compared to previous methods.

Abstract: Microfibrillated cellulose (MFC) was prepared from the bleached kraft hardwood pulp using TEMPO/NaClO/NaBr oxidation system and high pressure homogenization. By changing dosages of the TEMPO, NaClO and NaBr, the pressure and times of homogenization, pretreatment and homogenization process were optimized. Experimental investigation indicated that for making MFC of high quality, 0.25%TEMPO, 2.5%NaBr, 60%NaClO (based on oven dry pulp), 20 times of homogenization, pressure of 60MPa in the process of treatment were required. At last, the mechanical and barrier properties were tested after the base paper was coated by homemade MFC. The study suggested that mechanical properties (especially 5 times increase of the folding strength) increased substantially and air permeability decreased by 100times.

Abstract: Whiteness of wrapping paper is the main affecting factor of printed matter color rendition, the higher the whiteness, the better the results of color rendition. But the result of pursuiting high whiteness is that human eyes are harmed by the photic stimulation of paper-based printed matter. To solve the mentioned above problem, this paper preliminary researches the correlation between paper whiteness and asthenopia, the correlation between printing quality and paper whiteness, for finding out appropriate whiteness that can meet the eyes comfort and have better printing quality. Results show the asthenopia occurs easier as whiteness of wrapping paper increases. Besides, the paper samples with the whiteness values as 89.4% and 96.2% have the better printing quality, and the samples with the whiteness values as 84.6% have the worse printing quality relatively, but the quality gap is not big. Results show the whiteness of samples is between 84.6% and 89.4%, human eyes dont feel asthenopia and the printing quality is better. The research results can provide the theoretical basis for printing and packaging enterprises to choose paper which are suitable for printing packing and have eye-protection function, and contribute to the human eye protection.