Papers by Keyword: Paper Coating

Abstract: The composite SiO_x/polymer films are deposited as a top-coatings onto the paper substrates by radio frequency (RF) reactive magnetron co-sputtered two targets, silica and dicyclopentadiene dioxide cured with maleic anhydride (DCPD/MA).The samples prepared by changing P_SiO2 /P_DCPD/MA, the ratio of RF powers density delivered to the individual target from 0.1 to 10 so as to prepare different SiOx content coatings. The wettability, mechanical properties, color reproduction printability, chemical characterization of the coatings are discussed in this paper, using contact angle measurements, electronic tensile testing machine, off-set printing test and FTIR. The static contact angle of water ranges from 129.7 to 90.7 o and tensile performance has improved significantly as the ratio of RF powers density change from 0.1 to 10. The ink density and depth of color during off-set printing are visually improved by using papers with hydrophobic surfaces coated composite films.

Abstract: The penetration and diffusion of ink droplet in paper coating have significant influence on the image quality in the inkjet imaging. The flight physical phenomenon of the ink droplet was researched and analyzed according to the hydrodynamic equations of multiphase flow discrete phase in this paper. Base on studying on the surface structure of paper coating, the mechanism of impact, penetration and diffusion between ink droplet and paper coating also was researched in this paper from the perspective of energy conversion in the imaging process. The proposed mathematical model consisted of the factors of hydrodynamic characteristics for ink droplet and the physical characteristics of paper coating, we could get the maximum diameter of ink droplet spreading in paper coating through solving the model and obtain viscous loss and energy consumption in penetration of ink droplet by experiment, and then calculated the average penetration depth of ink droplet.

Abstract: Rice husk is a form of agricultural biomass that provides an abundant silicon dioxides source. This study used rice husk ash as a material to prepare paper coating. Silica powder has been synthesized by the refluxing of rice husk ash with HCl 1,2 and 3 M at different time (60 and 120 min.) The silicon dioxide extraction yield reached 85% and was effect by concentration of HCl solution and reaction time. The structure of the obtained silica powder were characterized by X-Ray Fluorescence (XRF), Particle size distribution (PSD), X-Ray diffraction (XRD), CIE L*a*b* (Visible spectrophotometer) and Scanning Electron Microscope (SEM). The highest purity of silica sample were 98.7% SiO2, CIE L*a*b* = 94.79 +0.48 +1.24, ∆E ≈ 3.28 (white powder) and 2Ɵ = 22o (silica). Particle had a uniform size less than 3 μm. The paper coating was made from acrylic resin mixed with synthesized silica that refluxing by HCl 2 M 120 min at different ratio (2%, 4% and 6%) and paper coated with a gravure printing machine. The qualities of paper coating were analyzed from viscosity, Transparency (Density) and color gamut of inkjet printing. The paper coating that mixed synthesized silica from rice husk 4% was highest qualities because have viscosity 358 ± 24.99ctp., Density = 0.19, and widely color gamut.

Abstract: In this paper, the effect of the charge of hydrophilic and lipophilic nanosized TiO₂ on the optical properties and printability of coated paper was investigated. The parameters including brightness, opacity, surface strength and sizing degree were used to evaluate the optical properties and printability of coated paper. The effects of hydrophilic and lipophilic TiO₂ on the properties of coated paper were discussed. It was shown that the optical properties and printability of coated paper increase persistently with the change of nanosized TiO₂ charged from 5% to 15%. Once the charge of nanosized TiO₂ was over 15%, the main properties of coated paper took on a downward tendency. The properties of coated paper were related to the surface properties of nanosized TiO₂ samples. It was found that the lipophilicity of nanosized TiO₂ sample played a more important role in the improvement of the coated paper properties, which was believed to be based on the fact that lipophilic nanosized TiO₂ could be well compatible with the binders used in the paper coating.

Abstract: In this paper, Water glass and sulfuric acid were used as raw materials to do the synthesis of hydrated silica by the method of precipitation, and then hydrated silica is applied in paper coating. By examining the changes of the coated paper’s various properties to study the effects of different reaction conditions to the final products. And then we obtained a optimal synthesis conditions: sulfuric acid concentration 25%, reaction time 50min, reaction temperature 80°C, sodium silicate modulus 2.8, stirring speed 150r/min, the relative amount of sodium sulfate content compared to SiO2 is 25% .And at last the outward appearance of the hydrated silica and the structural changes in paper coating were observed by scanning electron microscopy.

Abstract: The focus of this study is to investigate the effect of carboxylated styrene-butadiene rubber (SBR) latex on the dynamic rheologcial properties of paper coating suspensions modified with nanosized particles. The elastic storage modulus G′ and the viscid loss modulus G′′ are used to evaluate the dynamic rheologcial properties of paper coating suspensions. The effects of different amount carboxylated styrene-butadiene rubber latex on the flow parameters of paper coating suspensions are comparatively presented. It is shown that the dynamic elastic storage modulus G′ and viscid loss modules G′′ of paper coating suspensions increase with the SBR content change from 13% to 18%. The dynamic rheologcial properties are related to the strength of the network structure of paper coating suspensions. It is also found that the elastic storage modulus G′ of paper coating suspensions is larger than viscid loss modulus G′′, which indicates that paper coating suspensions in this investigation all behave like a viscoelastic solid.

Abstract: Effect of organic bentonite on rheological behavior of paper coating was studied. Organic bentonite was prepared by treating sodium bentonite with dimethyl diallyl ammonium chloride (DADMAC) at the following conditions: DADMAC 20%, reaction time 3h, reaction temperature 80°C and pH 9. The results showed that shear stress and voscosity of coating enhance with increasing the amount of organic bentonite. In this testing, all of flow curves fitted Cross model very much, and rheologiclal properties showed the pseudoplastic fluid, characterized as obvious shear thinning .The bentonite modified with DADMAC could promote the rheological behavior of coating.

Abstract: The infiltration and diffusion of ink droplet in paper coating have significant influence on the image quality in the inkjet imaging. The flight physical phenomenon of the ink droplet was researched and analyzed according to the hydrodynamic equations of multiphase flow discrete phase in this paper, and the energy distribution of ink droplet before contacting with the paper coating was calculated. Base on studying on the surface structure of paper coating, the mechanism of impact, infiltration and diffusion between ink droplet and paper coating also was researched in this paper from the perspective of energy conversion in the imaging process. The proposed mathematical model consisted of the factors of hydrodynamic characteristics for ink droplet and the physical characteristics of paper coating, we could get the maximum diameter of ink droplet spreading in paper coating through solving the model and obtain viscous loss and energy consumption in infiltration of ink droplet by experiment, and then calculated the average infiltration depth of ink droplet.