The Impact of Printing Substrate on Dot Deformation in Flexography

• Main Authors: Petar Miljković, Dean Valdec, Mile Matijević
• Format: Article
• Language: English
• Published: Faculty of Mechanical Engineering in Slavonski Brod, Faculty of Electrical Engineering in Osijek, Faculty of Civil Engineering in Osijek 2018-01-01
• Series: Tehnički Vjesnik
• Subjects: dot deformation; flexography; ink spreading; printing substrate
• Online Access: https://hrcak.srce.hr/file/302824

This study characterizes and compares the dot properties in flexography on coated and uncoated paper and on OPP film, with the use of conventional AM screening technology and photopolymer plate with flat top dots. A monochrome test form was created and printed with cyan ink on three different printing substrates. For the study of the dot deformation, microscopic images were taken from the prints and analyzed using ImageJ software. The primary area of the study are highlight tones since the reproduction of small dots is synonymous with high quality reproduction. All significant parameters of the dot deformation were evaluated, including the dot geometry, dot sharpness and uniformity of density. The image analysis showed that dot deformation is the result of spreading and penetration of the ink. The microscopic snapshots of the test areas on the prints show that ink penetrates significantly into the pores and holes of the uncoated paper, resulting in a non-homogeneous dot, thus losing its original shape. On coated paper and OPP film, the ink spreads more on the surface of the printing substrate and in such way gives a more homogeneous dot shape.