Effect of material properties on the paper cup manufacturing process

The disposable cup market has long relied on paperboard with a fossil-based polymer coating as a replacement for 100% plastic cups. Paperboards with biobased or biodegradable polymer coatings are aimed at reducing the fossil resource consumption of the packaging sector. However, as their properties are inherently different from traditional, fossil-based materials, they can face runnability issues. In order to establish a connection between certain material properties and runnability issues, four coated paperboard materials with differing surface and strength properties were converted into 250 mL/8 oz disposable drinking cups. The materials included two single-side extrusion-coated paperboards and two two-sided dispersion-coated paperboards. The cups were manufactured in two separate runs with minor machine adjustments to affect the resulting cup geometry. A comparison of the manufactured cups and material properties revealed the materials’ coefficient of friction to be the major cause of runnability issues or defects. Other suspected properties affecting the performance of cup materials included bending stiffness and compression strength.