Published on January 31st, 20131
How to Reduce Cost of Printing Paper
Researchers are dependent on printing their work, handouts to the students, pamphlets, and other important documents. In a large institution, there are large sums of money to be saved by taking print quality seriously. Research by Dr. ing. Gary Chinga and Professor Kristin Syverud highlight the importance of reducing “picking”, that is, making sure there are no unprinted spots on a printed image.
Print quality can be defined in several ways, depending on the paper grade or the printing process involved. For Super Calendared (high-quality uncoated paper suitable for magazines etc.) paper, the surface topography and the surface compressibility play essential roles in rotogravure printing. The print quality of Light Weight Coated paper may depend on the coating layer structure, which may control the ink-setting and influence print quality parameters like mottling or print gloss in heatset offset printing.
The definition of print quality in newsprint may involve the quantification of print-through, set-off, ink coverage and aspects related to linting. Chinga and Syverud have focused on the characterization of picking and lint particles. Picking is defined as the removal of paper fragments from its surface during papermaking or printing. Picking affects the print quality by creating unprinted spots on a printed image. In addition picking also increases lint build-up in a printing unit, which causes unnecessary costs for a printing house. It is thus important to control the picking tendency of a paper sample.
Adequate characterization methods for a proper quantification of picking are thus necessary. Such methods have been developed at the Paper and Fibre Research Institute (PFI), offering a good opportunity to quantify the picking degree of a given sample and, most importantly, the structural causes of picking.
Chinga, Gary & Kristin Syverud (2007) “Quantification of Paper Mass Distributions within Local Picking Areas” Nordic Pulp Paper Research Journal, 22(4): 441–446.
*Cover photo by Mary-Lynn