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Cutting objects at the molecular level

  1. Nov 28, 2006 #1
    So, I've read that cutting is essentially where the edge of the knife (or whatever cutting instrument) applies enough force to overcome the intermolecular forces in the object. A more dense object will have greater molecular forces, hence more difficult to cut (in the conventional cutting sense, as with a blade).

    My question is: Is there possibly a way to "aid" this cutting action by reducing the molecular bonds in some way, say electrically? In other words, an ionic bond, or a covalent bond, are from sharing of electrons. Would the application of a strong electrical field somehow reduce the strength of these bonds, hence allowing easier physical cutting? Or perhaps using a chemical of some sort (well, I suppose you could burn with acid)

  2. jcsd
  3. Nov 28, 2006 #2
    The simplest way would probably be to just heat up what you're cutting.
  4. Nov 28, 2006 #3
    hehe yes, that thought occurred to me as well - heat would decrease the force between bonds. As observed in real life - warm cheese or warm ice cream can be sliced and scooped easier.

    The material I'm interested in is paper. What different cutting techniques could be applied to paper, and how could a technique (other than laser) be used which would cut with less force needed?

  5. Nov 28, 2006 #4
    you've tried heating the scissors on the stove?

    On second thoughts, don't do that. I see it ending badly. Just having the blade sharpened is probably a safer way to get an improvement. You know, concentrate the pressure on the bonds you're aiming to break, to reduce the wasted force.

    Lasers out, but chemicals are ok? Have you tried wetting the paper (with water)?

    ..what prompted your question, niko?
  6. Nov 28, 2006 #5
    Well I'm working on a CNC paper cutting machine. The problem with using a knife is you have a certain amount of static friction to overcome, which can tear the paper and also requires more cnc motor power (I'm actually trying to convert a plotter to a cutter and sometimes their motors are not that strong). I could use a "rotary" razor cutter (which is shaped like a wheel) but they don't make them small enough.

    A laser would kick butt but I would need all the safety equipment to use it.

    Wetting the paper would theoretically work but of course wet paper cut-outs are not nice :)

    Another technique I am now looking into is high speed perforation - like the new "crayola cutter" - a needle bit which moves up and down at high speed and perforates the paper instead of cutting it. This would offer low side-to-side friction.

    So basically looking for alternative cutting methods, not just for the cnc cutter, but also out of curiosity as well, since I love physics :)

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