Controlled curing of air-permeable bonded webs

Abstract

Apparatus for curing a bonded, air-permeable web. The apparatus includes drying means (16-26, 42, 48, 54, 56 and 80) for passing heated air at a predetermined temperature through the web 10 for a predetermined time. Means (128, 132, 134, 136, 150, 160, 164 and 166) are provided for generating a first signal representing the pressure drop, at a predetermined velocity, across the web 10 outside of the drying means (16-26, 42, 48, 54, 56 and 80). Means (68, 108 and 110) are also provided for generating a second signal representing the pressure drop across the web (10) inside the drying means (16-26, 42, 48, 54, 56 and 80). Means (120) responsive to the first and second generated signals control the velocity of the heated air passing through the web so as to maintain the pressure drop across the web 10 inside the drying means (16-26, 42, 48, 54, 56 and 80) equal to the pressure drop as measured by the means (128, 132, 134, 136, 150, 160, 164 and 166) for generating the first signal.

Dependencies are inferred from the claim text.