Grades K–2 · Everyday Life
Why does sticky tape stay on a page?
A piece of sticky tape has a backing and a sticky layer. The backing is the strip we can hold. The sticky layer is already ready to stick; it does not need to dry like a puddle of glue.
In the diagramSticky tape holds by close contactAn enlarged edge view · bumps are exaggeratedSurfaceOrange backing · blue sticky layerThe soft layer meets the little bumps of the surface.
A page can look smooth while still having tiny bumps. Light pressure helps the soft sticky layer get close to those bumps. Tiny attractions between the materials help hold them together. The tape is touching the surface, not pulling on it from far away.
Loose dust can get between tape and a page. Then some of the tape meets dust instead of the page, so it may not hold as well. Different tapes and surfaces hold differently. This picture makes the bumps enormous so we can see the importance of close contact.
About this explanation
Starting knowledge: Recognize touching, pressing and a layer.
Sources
- 3M — Common Chemistry of PSA Tapes