in this study, medium density fiberboard (mdf), was produced by dry process using refined fibers from choob khazare caspian amol factory, with 3 levels of urea formaldehyde adhesive at 8, 10, and 12 percent, and 3 levels of paraffin at 0.5, 1, and 1.5 percent. from every treatment, cylindrical samples for permeability measurement with 13 mm in diameter, and 30 mm of height were cut using hole-s...