Scott Paper Company

Lawrence Vaalburg

Henry J Norton

Joel P Gotchel

Aris Constantine Spengos

H Paul Kaiser

Charles R Mason

David K Osteen

A method of making a nonwoven fibrous web. A web of primary fibers having uniformly distributed throughout secondary fibers containing 3 to 7 percent polyethylene by weight of the final web is formed on a conveying means. The polyethylene of the secondary fibers has a melting point that is lower than the melting point of the primary fibers. The web is then heated to a temperature below the melting point of the primary fibers but above the melting point of the polyethylene of the secondary fibers thereby causing some of the polyethylene fibers to bond to each other or to the primary fibers. The web is then heated to a temperature above the melting point of the primary fibers to form primary fiber-to-primary fiber thermal bonds which provide substantially all of the useful strength of the web.

Method of making a bonded nonwoven web

The method of autogenously bonding a nonwoven web formed predominantly of thermoplastic fibers is characterized by the steps of directing heat into the web from only one surface thereof to preheat the web, and then directing the preheated web through a bonding nip formed between opposed rolls, one of said rolls being hotter than the other roll, being capable of heating the web surface it engages to a temperature above the melt point of the thermoplastic fibers and being positioned to engage the surface of the web opposite the one into which heat was directed during the preheating operation; said webs being preheated by means completely independent of the opposed rolls that form the bonding nip, and most preferably by infrared panels. The nonwoven product formed in accordance with this method also forms a part of the instant invention.

Method of making nonwoven fabric and product made thereby having both

The invention resides in a method of forming a nonwoven web by employing a forming apparatus which includes a fiberizing roll for separating fibers from a feed mat and entraining them in a gaseous medium, a foraminous forming surface through which the gaseous medium passes and upon which the fibers are condensed to form a fibrous web, and a formation duct between the fiberizing roll and the forming surface for defining a flow path for the gaseous suspension of fibers from the fiberizing roll to the forming surface; the improvement wherein the formation duct includes front and back, substantially planar inner surfaces which may slightly converge in a direction from the fiberizing roll to the forming surface, but preferably diverge at an angle of up to about 41/2 degrees when the forming surface is a curved surface of a cylindrical drum, and up to about 11/2 degrees when the forming surface is a linear surface of a forming belt; the formation duct being inclined to the forming surface to define an incidence angle with the forming surface in the range of from about 10.degree. to about 30.degree. . The invention also resides in a method of forming a nonwoven web by employing the above-described apparatus.

Method of forming a nonwoven fibrous web

Web forming apparatus of this invention includes a fiberizing roll for separating fibers from a feed mat and entraining them in a gaseous medium, a foraminous forming surface through which the gaseous medium passes and upon which the fibers are condensed to form a fibrous web and a formation duct having an upstream end adjacent the fiberizing roll and a downstream end adjacent the forming surface, whereby the formation duct defines a flow path for the gaseous suspension of fibers from the fiberizing roll to the forming surface; the improvement including passageways at opposite sides of the apparatus adjacent the upstream end of the formation duct for communicating the duct with an atmosphere having a lower pressure than that within the duct for removing air to eliminate the adverse effect of vortices which are created by rotation of the fiberizing roll. A method of forming a fibrous web by employing the abovedescribed apparatus also forms a part of this invention.

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Brookhaven, PA, United States of America

Lawrence Vaalburg