Bookbinding and the Conservation of Books
A Dictionary of Descriptive Terminology

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couch roll

A roll or cylinder on a papermaking machine the purpose of which is to press, i.e., de-water, or COUCH (4) the newly formed web of paper from the wire, and to transfer the web to the wet press for further de-watering. Couch rolls are of two basic types: the suction couch roll and the pressure couch roll. The suction couch roll is a heavy metal shell drilled with numerous small holes through which a high vacuum exists for the rapid removal of water from the web as it travels over the roll. The pressure couch roll consists of two rolls which apply pressure to the web to remove water. (17 )




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