15. Wet Scroll (IYPT 2024)

demostration of task 15. wet scroll

https://www.youtube.com/shorts/1jp-CeeqkUw

Bilayer curling and winding in a viscous fluid

gives a basic theory for the phenomenon, if one side is tied up

https://www.researchgate.net/publication/255766216_Bilayer_curling_and_winding_in_a_viscous_fluid

Deformation behaviour of paper and board subjected to moisture diffusion

This paper presents a method to predict the through-thickness moisture content distribution and associated induced deformations of paper and cardboard sheets as they are subjected to relative humidity changes.

https://www.sciencedirect.com/science/article/pii/S0020768308004666

How wet paper curls

When a piece of tracing paper is placed gently on the surface of a bath of water, it rapidly curls up from one edge and rolls up due to the swelling of the side in contact with water. With time, as the swelling front propagates through the thickness of the paper, the paper gradually uncurls itself and eventually straightens out. The authors analyze the experimental dynamics of rolling and unrolling of the paper and complement these with a minimal theory that explains the basic observations.

https://iopscience.iop.org/article/10.1209/0295-5075/93/54001

Measuring the degree of curl of paper

In a method used to determine the tendency of paper to curl, a measurement is made of the amount of curl of a small piece of the paper floating on water. The measurement is customarily made in terms of an arbitrarily chosen angle. The maximum curvature, however, is a more logical measure of curliness. An effort has been made to determine the maximum curvature of freely curling paper from measurements made of the curling of paper in contact
with water, and the new apparatus devised for the purpose is described. The correlation of curl with other related properties is discussed.

https://nvlpubs.nist.gov/nistpubs/jres/30/jresv30n2p113_A1b.pdf