A strip of newspaper is folded in half and cut with a scissors and seen to be restored when opened out again.
There is a good torn and restored newspaper demonstration from Flinn Scientific. This relies on rubber cement to keep the paper together and provides a context for intermolecular forces between molecules.
https://www.flinnsci.com/api/library/Download/5537422a07664d95a1213f2504eb536d
Preparation
1. Cut a 2-inch strip of newspaper from the length of a sheet of newsprint.
2. Coat one side of the strip of newspaper with rubber cement and allow it to dry.
3. Lightly coat the dry rubber cement with baby powder.
Procedure
1. Show the uncoated side of the strip of prepared newspaper to the students.
2. Bring the bottom edge of the newspaper up so that the two coated sides face each other. Note: Keep the uncoated side toward the students.
3. Keep a finger between the top edges of the newspaper but lightly press the bottom folded area together.
4. Cut above the fold with sharp scissors.
5. Let the back edge of the newspaper fall; this will keep the uncoated side toward the students. The strip of newspaper will stay connected giving the illusion of an uncut strip of paper.
6. Repeat as desired.
Elmer’s rubber cement is difficult to obtain outside the UK. A suitable alternative is spraying the newspaper with two coats of repositionable glue spray, this was used in the video shown.
Always check the risks and safety of the glue you use!
Timstar and Mindsets online sell auto heal or self-healing tape. This silicon polymer sheet embodies the remarkable property of almost instant self-healing. If two freshly cut edges are pushed back together, new bonds form and in seconds it becomes virtually impossible to pull the cut open.
Similarly, if two clean surfaces are brought together, new bonds immediately form – making this one of the few known materials that can be welded to itself using pressure alone. It bonds to itself and only itself.