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Heat transfer problem

  1. Oct 20, 2005 #1
    How could I calculate how much time would be required to melt a plastic through a composite material?

    Composite is .005 inches paper and .0003 inches of Aluminum
    Plastic is .001 inches polyethlene with melting point of 325 F

    Assume heat source is uniform across area of composite
  2. jcsd
  3. Oct 20, 2005 #2

    Tom Mattson

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    According to the Physics Forums Guidelines (which you agreed to), you have to show how you started this problem.
  4. Oct 21, 2005 #3
    What I've done so far is research and realized my ability of working with differential calculus is lacking. But I do believe that the equations needed are:

    dQ/dt = kTA dT/dx

    1/kT=1/kPaper +1/ kAlu (so I can figure this out)

    A = 2pi 4 inches (1/8 inches)

    dQ/dt = the power supplied to the paper side which 1500 W ā€“ but I need to solve for dt (not sure how to re-arrange diff calc formula)

    dT/dx = (350-73) F to 25 F (So heat source is set at 350 F and the melt point of plastic is 325 F)

    I believe I need to consider the heat capacity of the plastic but Iā€™m not sure where ā€“ should it be added to the (kT) formula?
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