Why is packing tape nearly impossible to tear when intact, but easily shreds if you cut the slightest nick into it?
In: 6079
The polymer molecules that make up the tape are shaped like long chains. If you pull the tape, these chains align in the direction of pulling, and pulling more just packs them together as they become parallel to each other. On the other hand, if there already is a cut, there is alread one side of the bulk of polymers where there are no other molecules to bond to. Thus, pulling from the cut’s size is easier, especially if you pull off-plane, where there is no inherent resistence of the material (the forces among molecules are all applied within the thin tape).
Latest Answers