Multiple zone limiting orifice drying of cellulosic fibrous structures, apparatus therefor, and cellulosic fibrous structures produced thereby
AssigneeThe Procter & Gamble Company
InventorsDonald E. Ensign, Michael G. Stelljes, Jr., Paul D. Trokhan
Life of this patent
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Abstract
A limiting orifice through-air-drying apparatus for papermaking or other absorbent embryonic webs. The apparatus has a first zone and a second zone. The first zone is maintained at a differential pressure less than the breakthrough pressure, while the second zone is maintained at a differential pressure greater than the breakthrough pressure. The residence time of the embryonic web to be dried with the apparatus is maintained at preferably less than 35 milliseconds on the first zone. Using the dual zone system described above, the overall energy required to run the apparatus can be reduced.
Claims12
A limiting orifice though-air-drying papermaking apparatus in combination with an absorbent embryonic web having moisture distributed therein, said apparatus comprising a limiting orifice for airflow through said embryonic web, wherein said apparatus further comprises a plurality of distinct zones, comprising, in order, at least a first zone and a second zone, said distinct zones having mutually different differential pressures relative to the atmospheric pressure, and having means to enable said embryonic web to have a residence time on said first zone of less than about 35 milliseconds.
Dependencies are inferred from the claim text.