The researchers sprayed standard A4 printer paper on one side with an ink consisting of water and glycerol. They then used a laser scanner to observe the curvature of the sheets over time, finding that once printed, solvents in the ink begin to slowly migrate through the paper towards the unprinted side.
Paper Curving Phenomenon
As the solvents migrate, they cause the paper to curve. This effect is most pronounced at the edges of the printed area, where the solvent concentration is highest. Over time, the paper will eventually flatten out again as the solvents fully penetrate the paper.
The degree of curvature and the rate at which it occurs depend on factors such as the type of paper, the composition of the ink, and the environmental conditions. Thicker papers or those with a higher moisture content tend to curve more dramatically.
Understanding this paper-curving phenomenon is important for various applications, such as inkjet printing, where it can affect print quality and alignment. It also has implications for the design of paper-based devices and structures, where the dimensional stability of the material is a key consideration.