Backwards is better, Corrugating International, November 1999, Vol. 1(3)
A common practice in the corrugating industry groups the hot plates of a double facer into two or more sections using higher steam pressures and temperatures to operate in the first section. Subsequent sections have lower pressures and temperatures. Another custom is using more ballast on the leading hot plates than on those downstream. These practices shown schematically in Fig. 1 may seem to make sense, but they are inconsistent with some important thermodynamic principles. For heat energy to flow, scientific inquiry long ago established that a temperature differential must exist.
Backwards is better, Corrugating International, November 1999, Vol. 1(3)