US 4,344,818 A · Air/water hybrid former

Abstract

A method and apparatus especially adapted to produce a ply separable web requiring substantially less energy input for drying. The apparatus comprises a headbox having at least three stock flow channels, the outer channels being adapted to convey conventional aqueous stock solutions, with at least one inner channel adapted to convey airborne fibers. The resulting web, having a significant portion of the fibers in a dry state, requires less energy to dry, and the distinct layers provide shear zones therebetween which permit ply separation upon creping. Different fiber types may be provided in different layers depending upon product attributes desired, and the products may be conventionally dried or may be throughdried. An alternative embodiment requires the mixing of airborne fibers with an aqueous solution adjacent to or within the headbox, producing only surface wetting of the fibers and reduced interfiber bonding.

Claims6

Dependent claims

A method of forming a multi-layer absorbent web from a single headbox comprising:

(a) forming a first outer layer of papermaking fibers from an aqueous fiber stock slurry provided from a first flow channel of said headbox;
(b) forming a second inner layer of fibers, said fibers in said second inner layer being provided from a second flow channel of said headbox and being entrained in an air stream and having reduced inter-fiber hydrogen bonding therebetween;
(c) forming a third outer layer of papermaking fibers from an aqueous paper stock slurry provided from a third flow channel of said headbox;
(d) dewatering said first and third outer layers of fibers such that significant inter-fiber hydrogen bonds are formed between fibers within each of said first and third layers;
and
(e) creping at least one of said first or third outer layers of fibers.

3 more elements

Dependencies are inferred from the claim text.

Air/water hybrid former

Life of this patent

Air/water hybrid former

Life of this patent

Abstract

Claims6