in: Sanat ve Kültür Çalışmaları, Dr. Öğretim Üyesi Semra KILIÇ KARATAY, Editor, İksad publishing house, Ankara, pp.16-27, 2020
Paper has been used in many industries for centuries, but in recent years it has been rediscovered as a base material for sustainability and reducing the carbon footprint. There are numerous reasons why it is preferred as a simple cellulosic substrate material all over the world, some of them can be listed as its mechanical properties, three-dimensional fiber structure, biodegradability and sustainability, ease of production and modification, reasonable price and ease of access. Although many printing methods have been developed on paper printing in the last century, screen printing is still used as it is possible to print on different materials. The physical properties and weaving density of base material are the most important factors that affect color in screen printing. The surface smoothness and porosity of the base material affect the color quality of all kinds of colored liquids such as paint and ink, which are printed on the paper surface. Flow and absorption properties of liquids in media with porosity are mathematically formulated by Kozeny-Karmen, D'arcy and Lucas Washburn. The main structure of the screen printing frames made up of weaved fabric having weft and warp yarns. The yarn diameter and density of this fabric are the second most important parameters affecting the color value due to ink transfer on the material. For this reason, in this study test prints were made on 3 different papers coated and uncoated with different surface characteristics, using solvent-based cyan inks and 4 different mesh weaving densities. Other important parameters that have a direct impact on quality in screen printing; such as the squeegee shape and hardness, printing pressure, printing speed, ink viscosity, squeegee angle, and weaving tension; were held constant in these test prints and applied with a semi-automatic screen printing machine. The L*a*b* values of the prints were measured with a spectrophotometer and the total color difference (ΔE) values were calculated by comparing with the standard values and shown in graphics. The data obtained were analysed and the effect of paper surface properties on the total color difference (ΔE) was examined. The surface and interface images of the printing samples were taken by an Electrostereoscopic microscope and the ink penetration was examined with the microscope. When the findings obtained as a result of the examinations and measurements were evaluated, it was determined that the color deviation decreases as the density of weaving increases. It has been determined that the surface structure and porosity of base materials such as paper and cardboard affect the color value depending on the thickness of the ink film.