Compression-drawing of moisturized paperboard: Experiments on moisture and temperature dependencies

For the industrial production of paperboard packaging, knowledge about the process window of the forming operation is crucial information. This study presents how blank moisturization shifts the process window of a compression drawing process. A hydraulic press was utilized to draw circular cups, and their quality was evaluated by counts of defects and wrinkles. The experimental part further includes measurements of the materials’ friction and tensile properties. It was found that both blank moisturization and increased blankholder force increased the wrinkle count and therefore improved the forming quality. However, the combination of high blankholder force and blank moisturization did not lead to superior forming quality. Rather, there were structural defects in the samples. A multilinear regression model was developed to predict wrinkle quantity based on tool temperature, material moisture content, and blankholder force.