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AYDEMİR, CEM

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AYDEMİR

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CEM

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Now showing 1 - 3 of 3
  • Publication
    Effects of matte coating on the paper surface and print density
    (WALTER DE GRUYTER GMBH, 2013) AYDEMİR, CEM; Aydemir, Cem; Ozomay, Zafer; Karademir, Arif; Kandirmaz, Emine Arman
    In this work, standard laboratory printing applications with IGT (ISO 12647-2) were applied on uncoated and matte-coated papers using offset inks (DIN ISO 2846-1). Surface roughnesses of uncoated and coated sheets were recorded to be 195 and 13 ml/min, respectively. Air permanence values of uncoated and coated papers were found to be 5.6 and 0.103 mu m/Pa.s, respectively. Changes in the print densities were recorded up to 48 h. Print density changes for uncoated and matte-coated papers were surprisingly found to be in similar paths (8% in the first 4 h), although significant differences between surface roughnesses were recorded. Furthermore, paper samples showed similar behaviors for the percent volume changes, where drop volume disappeared within 6 min. It is concluded that matte coating did not have any significant effects on print density change and drop volume change.
  • Publication
    A study on the printability properties of alkali-sized recycled papers
    (WALTER DE GRUYTER GMBH, 2016) AYDEMİR, CEM; Aydemir, Cem
    Recycled handsheets were prepared from old newspapers and old office papers with internal sizing applications of alkyl ketene dimer (AKD) emulsion at 0.5%, 1.0% and 1.5% addition levels as received basis. Handsheets made at 80 g/m(2) were air dried and oven dried as placed in drying rings followed by conditioning prior to testing. The contact angle, surface energy and drop volume changes of handsheets were carefully measured as well as used some offset printing applications. Freeness levels of pulp from newspapers and office papers were measured to be 65 and 45 SR degrees, respectively. It was confirmed that AKD sizing improved paper resistance against water and printing ink, and this was further improved with oven drying. Contact angle values obtained from oven-dried office papers and newspapers were in the range of 105 degrees-95 degrees and 85 degrees-75 degrees, respectively. Without drying, lowest contact angles from newspapers and office papers were recorded to be around 72 degrees and 37 degrees, respectively. Results were in agreement with surface energy values of samples which were around 60 mJ/m(2) for air-dried samples and over 30 mJ/m(2) for oven-dried handsheets. It was concluded that sizing actually improves print quality but may also increase colour change differences over time as represented by Delta E.
  • PublicationOpen Access
    The examination of vegetable- and mineral oil-based inks' effects on print quality: Green printing effects with different oils
    (SAGE PUBLICATIONS LTD, 2018-07) AYDEMİR, CEM; Aydemir, Cem; Yenidogan, Semiha; Karademir, Arif; Kandirmaz, Emine Arman
    Introduction: Printing inks oil selection is related to the desired nature of the varnish in the ink production. Petroleumderived mineral oils and vegetable oils can be used in offset inks. Methods: In this study, the behaviors of vegetable- and mineral oil-based inks on uncoated and coated paper surfaces were investigated in terms of printability. Solid tone test prints were done with offset printing of these inks. Print gloss of the printed samples was measured and a light fastness test was implemented on these samples in order to determine the resistance to fading. Absorption behavior and contact angles of the ink-printed films on the test papers were measured with the sessile water drop method depending on time, and surface energies were calculated. Results: On both paper types, linseed-soybean oil-based vegetable ink gave the highest brightness value. The lowest print gloss results on the paper were obtained from soybean oil-based inks. The lowest color change was recorded with mineral oil-based inks on gloss-coated papers. According to the ink-film-surface relation, when the contact angle is high, surface energy decreases and the absorbency of the ink-film is lower. Conclusions: In this study, the behaviors of vegetable- and mineral oil-based inks on different paper surfaces, and the effect on the quality of printability as well as differences, have been evaluated, taking environmental and health factors into consideration.