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WOS:000486383100017 One of the keys to improving print quality is to experimentally characterize the paper surface, structure and printability to obtain quality control mechanisms. In multi-color prints, determining the differences in the acceptance of the next color ink by the surface of the paper or the ink film that was previously printed is important for print quality. The criteria, such as ink setting, adhesion, color, gloss and density, in the printing process, depend on the wettability and absorbency of the paper. The surface structure of the paper is the most important factor in determining the hydrophobic properties. In this study, wetting and absorption dynamics of the printed partially hydrophobized paper surface were investigated. The aim was to measure the effect of the printed ink film on the wetting (surface free energy) and liquid absorption behavior of the paper. Liquid absorption changes on printed/unprinted paper surfaces were measured by the sessile drop method, using a contact angle-measuring device. The surface energies of the papers were calculated and evaluated according to the surface contact angle of the droplet. Marmara University, Commission of Scientific Research Project (M.U. BAPKO)Marmara University [FEN-B-100615-0271] This work was supported by Marmara University, Commission of Scientific Research Project (M.U. BAPKO) under grant FEN-B-100615-0271.

International audience; In this work, we explored the elaboration of new smart paper by coating fiber-based materials with CNC for possible use in packaging. Particularly, we investigated application of a 100% CNC layer onto a substrate. Mainly due to the cost and limited availability of CNC on a large scale, few studies have examined these opportunities. Several layers of CNC were deposited onto a paper material using the bar-coating process to improve relevant properties of the paper surface. Surface analyses (atomic force microscopy, scanning electron microscopy, and transmission electron microscopy) were performed to elucidate the CNC network at the paper surface. Structural and mechanical properties of the final materials were evaluated. Results of general interest were obtained about barrier properties. The air barrier and grease resistance improve only with the paper coated with CNC. To complete this research, a small amount of polyethylene glycol was added to reinforce the brittle CNC coating and clearly enhance barrier properties of the paper.

Attempts were made to plasma deposit an oriented π-conjugated polymer of pyrrole (Py) on paper surfaces in order to produce electrically conductive layers. The N/C atomic ratio of 0.13–0.24 was observed for all treatment conditions. This implies the nature of the deposition formed on the paper surface via pulsed plasma is different from that of pyrrole monomer. An increase in conductivity of all pyrrole-plasma treated papers was observed. The 50 W RF-power with 5 min plasma exposed paper sample shows 8.15 × 10−9 S·cm−1 conductivity. The conductivity measurements indicated a plasma-enhanced ring-opening reaction mechanism of pyrrole.

Tribological measurements of graphic products include investigation of dynamic friction and print wear. Abrasive damage of prints is an important parameter in determining the mechanical resistance of the print's surface. The acceptability of the results of tribological measurements depends on the expected life-cycle of the print and its use. Therefore this type of measurements is performed for a much broader range of prints than just the packaging prints. In our study we examined the influence of substrate surface on the stability of Ink Jet - IJ printing. For this purpose we chose different samples of paper (varying in quality, basis weight, composition, surface treatment). The analysis of paper surface (smoothness, roughness, porosity) was first done on unprinted paper. After that we measured the dynamics of water penetration. All the paper samples were subject to IJ printing, magenta and black colour separately. The samples were exposed to Resistance to heat test, according to the ISO-11798 standard. The mechanical stability of prints, expressed as rub-off resistance, was measured before and after test. Two different methods were used: Quadrant and Pira Wallace. The obtained results represent a part of a larger study on the behaviour of various types of master less printing. Most of the toners and inks used in these printing techniques contain pigments, as opposed to IJ printing, which uses dyes.