Process and apparatus for contacting a powder with a fibrous web

摘要

A process for contacting a moving fibrous web with a powder. The process comprises the steps of: I. passing a mixture of powder and air through the moving fibrous web; II. reversing the direction of movement of the fibrous web; and then III. passing a mixture of powder and air through the moving fibrous web in a direction opposite to that of Step I. An apparatus comprising an air-tight enclosure; means for maintaining subatmospheric pressure within the enclosure; means for passing a fibrous web through the enclosure; and means within the enclosure for passing a mixture of powder and air through the moving fibrous web.