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US 4,581,254 AGranted
Foam applicator used in paper treatment
AssigneeUnion Carbide Corporation
InventorsCharles J. Cunningham, Russell L. Brown
Life of this patent
Estimating the term…
Abstract
Foam applicators having specific lip configurations and substrate orientation, used for applying foamed treating compositions to substrates, including rapidly moving paper, provide uniform distribution of treating agent onto the substrate.
Claims12
A foam applicator comprising, in combination:
- (a) a base;
- (b) an upstream lip and a parallel downstrip lip both extending angularly from the base;
- (c) a foam application chamber extending between interior walls of each lip and enclosed at each end by end walls;
- (d) one or more openings in the base providing for movement of a uniform distribution of foam into the chamber from foam generation means;
- (e) top inside and outside edges of the upstream lip;
- (f) a top outside edge of the downstream lip;
- (g) a rim between the top outside edge and the interior wall of the downstream lip;
- (h) an upstream lip relief Angle A formed by the inside edge and the interior wall of the upstream lip;
- (i) a downstream lip relief Angle B formed by the outside edge and the interior wall of the downstream lip;
- (j) an orifice extending between the top inside edge of the upstream lip and the rim of the downstream lip effecting application of the foam to a substrate passing across the orifice;
- wherein,
- (k) Angle A is greater than or equal to 90.degree.;
- (l) Angle B is less than 90.degree.;
- and
- (m) the upstream lip extends farther from the base than the downstream lip.
12 more elements
A process for treating paper comprising:
- (1) producing a fast-breaking, fast-wetting, limited stability foam of a liquid treating composition;
- (2) passing the foam through one or more openings in a base of a foam applicator providing a uniform distribution of the foam to a foam application chamber extending between interior walls of an upstream lip and a parallel downstream lip both extending angularly from the base, with the chamber enclosed at each end by end walls;
- (3) passing a paper web across and contacting the lips along a top edge of the upstream lip and along a rim between a top outside edge and interior wall of the downstream lip;
- wherein the paper web:
- (i) approaches the upstream lip at an upstream entrance angle C away from perpendicular;
- (ii) leaves the upstream lip at an upstream exit angle D away from perpendicular and towards the base;
- (iii) approaches the downstream lip at a downstream entrance angle E away from the interior wall of the downstream lip;
- and
- (iv) leaves the downstream lip at a downstream exit angle F away from the direction of approach to the downstream lip;
- wherein:
- angle C is greater than or equal to 0.degree.;
- angle D is greater than 0.degree.;
- angle E is greater than 90.degree.;
- angle F is greater than or equal to 0.degree.;
- and
- (4) applying a controlled amount of the foam to the surface of the paper web providing a uniform distribution of the treating composition on the paper web.
13 more elements
Dependencies are inferred from the claim text.