Danish researchers have investigated the dangers of cutting papers

When, how, why? Danish physicists have very seriously determined which paper is the sharpest and at what angle.

You grab a sheet of paper from the printer, you turn the page of a book a little too quickly, or you close an envelope without paying attention, and… you cut your finger, that ridiculous little cut that hurts so much. And you probably thought to yourself: but how can a simple sheet of paper manage to cut you? This is exactly the physics problem that researchers at the Technical University of Denmark have just solved.

How? By using an “artificial finger” made of gelatin that reproduces the characteristics of human skin and flesh. And on it, they tested all kinds of paper: wrapping paper, postcard paper or even photos. They determined the best angle for the paper to cut, studied the deformation of the paper, its flexibility, or even the ideal pressure.

Result: the most dangerous paper is neither too thin, because then it bends, nor too thick, because it does not exert enough pressure. The sharpest has a thickness of 65 micrometers, which corresponds to what is called matrix paper and which fortunately is not used much anymore. On the other hand, the second most dangerous is widespread: magazine paper. Also know that the best angle to cut yourself is when the paper penetrates the skin at an angle of 15 degrees.

By discovering as they say “the surprising power of paper”researchers at the Technical University of Denmark did not stop there: they 3D-built a machine with super-sharp paper, which they called “paper machete”a paper machete. And with it, they managed to cut cucumber, peppers, potatoes, and even chicken. Beyond the anecdote, these results will allow paper manufacturers, printers and publishing houses, perhaps tomorrow, to make paper that is a little less sharp.