18 years ago
I am having a hard time finding heat transfer coefficients (k) for
various polymers (nylon, polyester, polyethylene). Would anybody know
an online source?
I am trying to perform finite element methods to determine the
required seal times at various temperatures on packaging lines. Has
anybody perfomed this type of calculation before or know of an
Generally, packaging machines have dwell times of approximately 0.4+
seconds with sealer bar temperatures of 170-175 deg C. The sealing
material, generally polyethylene in this case, requires to be raised
to approximately 140-145 deg C in order to achieve an even seal. The
back side sealer bar is normally kept at room temperature, or slightly
above. The pressure applied to the sealer bar can vary, but it is
assumed that full contact is made between the sealer bar and the
polymer film and that the surface of the film reaches the sealer bar
Thank you for your suggestions and opinions.