System for applying binding agents to fibrous webs
AssigneeAmerican Can Company
InventorsWalter L. Pauls, Raymond A. Dunleavy, III
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Abstract
A method and system for applying a foamed binding agent to a fibrous web is disclosed. The invention is characterized by the use of an extruder having an upper lip extending 1/16 to 1/4 inch beyond the lower lip, and by the drawing of a vacuum beneath the applied foam, said characteristics being critical to the formation of a uniform foam layer atop the web. A second, more substantial vacuum is then applied beneath the web to essentially completely draw the binding agent into the web thereby providing substantial inter-fiber bonding.
Claims5
An apparatus for applying binding agent as a foam to a fibrous web supported by a moving foraminous carrier wire, comprising:
- a foam extruder having means defining a flow passage terminating in an elongate orifice extending transversely of the direction of movement of said wire, said flow passage being inclined between about 2.degree. and about 25.degree. to the plane of said web in a direction opposite to the direction of wire movement,
- said elongate orifice including a pair of longer edges positioned at substantially the same distance of from about 1/4 and about 3 inches above said web, and spaced one from the other, in the direction of wire movement, a distance of from about 1/16 inch to about 1/4 inch,
- and a first vacuum means disposed beneath said wire, and, as respects the direction of wire movement, at a point just downstream of said elongate orifice, said first vacuum means being operative to draw a vacuum of from about 0.1 inch to about 1.0 inch of water.
Dependencies are inferred from the claim text.