Abstract: A method for producing a self-sustaining sheet of essentially cellulosic fibrous material with improved strength wherein a dry-laid web is moistened and then consolidated by passage along a heated consolidating surface wherein the web is held against this surface by one side of a supporting band, against the other side of which at least two spaced apart pressure rolls exert a pressure acting through the supporting band against the web, which pressure is preferably between 150 and 500 pounds per linear inch. The supporting band thereby maintains the web against the heated consolidating roll between said pair of pressure nips.

Abstract: Apparatus for dry-laying cellulosic fibres on a foraminous travelling band comprises a distribution chamber one wall of which facing the band is provided by a vibratable screen. Within the chamber is a rotating brush roll positioned so that the brushes cause the screen to vibrate. Fibres are urged through the screen partly by the action of the brush roll. Provision may be made for recirculating air which has passed through the band back to the chamber.

Abstract: Foldable boxboard made by dry-laying cellulosic fibers and 1-10% starch. The boxboard has a weight of at least 210 g.s.m., a stiffness in the machine direction of at least 5.8 Kenley units, and a ratio of stiffness in the machine direction and in the cross-machine direction of substantially 1:1.

Abstract: In dry forming a layer of fibers, the fibers are conveyed by carrier air to a distributor housing having a perforated bottom wall through which the fibers pass downwards on to a foraminous forming surface connected on its underside to a suction box. The invention ensures that the fibers pass from the distributor to the forming surface under the influence of suction and gravity alone so as to provide a layer of more uniform depth than hitherto obtained by dry forming.

Abstract: An apparatus for forming a multi-ply sheet of paper in which a first web of cellulosic fibers is dry formed and consolidated, a second web of cellulosic fibers is separately dry formed and consolidated, and the two thus consolidated webs are combined into a single multi-ply sheet of paper or paperboard.

Abstract: A process for making a multi-ply consolidated dry-formed fibrous web having at least three plies, the outer plies are impregnated with a stiffening agent (e.g. starch) and the intermediate plies are impregnated with a sizing agent (e.g. wax/rosin size) to render them impervious to the stiffening agent. After the web has been consolidated by hot moist pressing, its outer surfaces may be further sized and hot moulded.

Abstract: A distributor box for dry forming a layer of fiber on a forming surface spaced below it, wherein obturators, e.g. dependent flaps, are located around an air gap between the bottom of the box and the forming surface in pre-selected position to modify the lateral air flow induced into the air gap and so assist the formation of a layer with a uniform depth.

Abstract: A process and apparatus for forming a multi-ply sheet of cellulosic fibrous material. A dry-laid mat and a wet-laid web of cellulosic fibers are joined together and concurrently the dry-laid mat is consolidated by the concurrent application of heat, pressure and moisture, the moisture being derived from the wet-laid web.

Abstract: This invention concerns apparatus for moulding ribs, ridges, studs or other upstanding projections on a mouldable material and although not so restricted it will hereafter be described with reference to its use on apparatus for moulding dry formed fibrous material.

Abstract: Apparatus for consolidating a dry-laid web of fibers comprising means for moistening the web, a heated surface, a backing which holds the moistened web against the heated surface, and at least two spaced apart pressure rolls which press against the backing to define with the heated surface pressure nips to increase the pressure on the web against the heated surface at the nips and wherein the backing holds the web against the heated surface between the nips.

Abstract: Apparatus for dry forming one or more fibrous layers on a forming surface to provide eventually fiberboard or paper in which the fibers are fed by carrier air to a distributor immediately above the forming surface. The rate of flow of the carrier air and its fiber concentration are adjusted to match the distributor requirements by removal of some of the carrier air in a cyclone separator upstream of the distributor. Any removed fibers are fed back into the remaining carrier air.

Abstract: A method and apparatus for making a multi-ply paper sheet wherein a first web is formed by wet-laying fibres and a second web is formed by dry-laying fibres, the two webs being combined to form a multi-ply sheet and wherein the dry-laid web is produced by depositing dry fibres on a supporting band and consolidating the web by hot moist pressing before transferring to the first wet-laid web.