Apparatus and process for forming a laid fibrous web
AssigneeKimberly-Clark Corporation
InventorsKenneth M. Enloe, Timothy L. Wehman
Life of this patent
Estimating the term…
Abstract
Apparatus and process for forming a laid fibrous article includes a foraminous forming surface for depositing thereon of fibers under the influence of a pressure differential imposed on the surface, wherein the improvement comprises the provision of a concavely contoured portion of the forming surface to yield a non-stepwise gradation in basis weight of the laid fibrous article. The concavely contoured surface portion is bounded by walls defining angles of from about 45.degree. to 68.degree., whereby the laid fibrous article is readily removable from the forming surface, which may comprise the cylindrical surface of a rotating drum.
Claims27
A method for forming a fibrous article, comprising the steps of:
- providing a rotatable cylindrical drum, an outer circumferentially extending cylindrical wall surface of which is comprised of a foraminous forming surface;
- defining an annular space between said forming surface and an inner ring, which rotates with said forming surface and is capable of passing air therethrough;
- substantially preventing a circumferential movement of air through said annular space with a plurality of circumferentially spaced, transverse sealing members, said transverse sealing members connected in said annular space in sealing engagement between said inner ring and said forming surface;
- dividing the interior of said drum into plural arcuate segments with a plurality of radially extending stationary baffles, said arcuate segments defining and communicating with respective differential pressure zones on said forming surface, and said differential pressure zones including a vacuum laydown zone located on a portion of said forming surface over a first of said interior arcuate segments;
- substantially preventing an intrusion of ambient air around an edge of said baffles with a sealing flange member which contacts said inner ring with a slideable, sealing engagement and which extends axially across a width dimension of said baffle and extends circumferentially with a length at least equal to a circumferential distance between consecutive transverse sealing members;
- drawing air through the vacuum laydown zone on the forming surface into the first arcuate segment and out of the rotatable drum;
- and
- depositing fibers onto said forming surface under the influence of said air drawn through said vacuum laydown zone.
An apparatus for forming a laid fibrous article, comprising:
- a foraminous forming surface for depositing fibers under the influence of a pressure differential imposed on the forming surface;
- a rotatable cylindrical drum, an outer circumferentially extending cylindrical wall surface of which is comprised of said forming surface;
- an inner ring which is capable of passing air therethrough and which is connected to rotate with said forming surface and define an annular space therebetween;
- a plurality of circumferentially spaced, transverse sealing members connected in said annular space in sealing engagement between said inner ring and said forming surface;
- a plurality of radially extending, stationary baffles sealingly disposed in the interior of said rotatable cylindrical drum to divide the interior into plural arcuate segments, said segments defining and communicating with respective differential pressure zones on the forming surface, and said differential pressure zones including a vacuum laydown zone located on a portion of said forming surface over a first of said interior arcuate segments;
- a sealing flange member connected to a selected stationary baffle and arranged to contact said inner ring with a slideable, sealing engagement, said sealing flange member extending axially across a width dimension of said stationary baffle and extending circumferentially with a length which is at least equal to a circumferential distance between consecutive transverse sealing members;
- and
- pneumatic flow means comprising vacuum suction means joined in gas flow communication with said first arcuate segment in said rotatable cylindrical drum for drawing air through the vacuum laydown zone on the forming surface into the first arcuate segment and out of the rotatable cylindrical drum.
Dependencies are inferred from the claim text.