3m Innovative Properties Company

Minnesota Mining and Manufacturing Company

Douglas C Sundet

James F Pitzen

Dean R Duffy

John M Brandner

Rahul R Shah

Tien T Wu

Donald E Young

Lowell E Christensen

Andrew R Fox

Michael R Berrigan

Seyed Abolhassan Angadjivand

John D Stelter

James C Breister

William T Fay

William P Klinzing

Patrick J Sager

Andrew W Chen

Matthew S Linabery

John A Futhey

Albert H Fox

A pleated filter is made from a monocomponent monolayer nonwoven web of continuous monocomponent meltspun partially crystalline and partially amorphous oriented fibers of the same polymeric composition that are bonded to form a coherent and handleable web having a Gurley Stiffness of at least 100 mg and which further may be softened while retaining orientation and fiber structure. Rows of pleats are formed in the nonwoven web, and the web is cut to a desired size and shape to provide a pleated filter element containing a self-supporting porous monocomponent monolayer matrix of fibers bonded to one another at least some points of fiber intersection and having an average initial submicron efficiency of at least 15% at a 1.52 meters/sec face velocity. The filter element is deformation resistant without requiring stiffening layers, bicomponent fibers, adhesive or other reinforcement in the filter media layer.

Pleated filter with monolayer monocomponent meltspun media

The present invention is a filter that includes a length of filter media and a continuous, substantially nonlinear adhesive strand. The filter media has a front face and a rear face. The filter media has a plurality of pleats defined by a plurality of fold lines, each fold line being intermediate oppositely sloping first and second wall surfaces. The plurality of fold lines comprise a first plurality of pleat tips and a second plurality of pleat valleys. The adhesive strand is provided on the front face of the filter media in discontinuous contact with the filter media. The adhesive strand contacts the filter media at a pleat tip and contacts the filter media at a portion of a first wall surface and contacts the filter media at a portion of a second wall surface.

Self-supporting pleated filter media

Herein is disclosed a pleated filter comprising an upstream face and a downstream face and comprising at least one flexible inextensible tridirectional scrim in discontinuous contact with the downstream face of the pleated filter and bonded to the pleat tips of the downstream face of the pleated filter. In additional embodiments, an additional tridirectional scrim may be provided in discontinuous contact with the upstream face of the pleated filter and bonded to the pleat tips of the upstream face of the pleated filter. In further embodiments, at least one continuous, substantially nonlinear adhesive strand may be provided on at least one face of the pleated filter.

Pleated filter with tridirectional scrim

A filter element in the form of a nonwoven self-supporting filtration web having rows of folded or corrugated spaced-apart pleats, the web containing continuous thermoplastic fibers a majority of which are aligned at 90&#xb0;&#xb1;20&#xb0; with respect to the row direction. The filter element can be made by forming rows of pleats in such a nonwoven web and cutting the web to a desired size and shape. The filter elements can provide improved mechanical and filtration properties and can exhibit reduced susceptibility to pleat deformation and the loss of space between pleats.

Pleated aligned web filter

Methods and apparatus for meltblowing utilize an auxiliary manifold to dispense a fluid between an orifice of a die that is expelling polymeric fibers and an exit of a duct that is dispensing a secondary flow of gas onto the fibers. The fluid dispensed from the auxiliary manifold reduces a recirculation zone of the secondary flow between the exit and the orifice that, absent the fluid from the manifold, results in errant fibers that are blown back into the face of the die by the recirculating secondary flow.

Methods and apparatus for meltblowing of polymeric material utilizing fluid flow from an auxiliary manifold

Manifolds are designed to deliver fluid through multiple orifices of the manifold such that for a given inlet fluid pressure the fluid being output from the multiple orifices has a desired mass flow profile. The desired mass flow profile includes a desired mass flow rate and a desired direction and distribution of flow in three-dimensional space. The manifold is first modeled as a two-dimensional representation to determine manifold parameters necessary to achieve the desired mass flow profile within the two dimensions. Then, the manifold is modeled as a three-dimensional representation based on the parameters previously determined for the two-dimensional representation to determine manifold parameters of the third dimension that are necessary to achieve the desired mass flow profile within the three dimensions.

Manifolds for delivering fluids having a desired mass flow profile and methods for designing the same

A self-supporting, pleated filter including a plurality of pleats in a filter media that extend along a front face and a rear face. The pleats include a plurality of pleat tips and sloping side surfaces generally perpendicular to the direction of pleating. At least one planar reinforcing strip oriented in the direction of pleating is bonded to the pleat tips on the front face. At least one reinforcing member is positioned along the rear face of the filter media. The reinforcing member may be a reinforcing strip oriented in the direction of pleating and bonded to the rear face of the filter media. A second planar reinforcing strip may optionally be bonded to the reinforcing strip pleat tips. The reinforcing member, the first reinforcing strip and the second reinforcing strip can be aligned to form a truss structure.

Self-supporting pleated filter

A device for facilitating removal of a filter from an air circulation system includes a flexible element having a first, low profile position adjacent a surface of the filter and a second, extended position spaced from the surface of the filter. When in the extended position the flexible element provides a graspable or grippable medium for removing the filter from the air circulation system. The device also includes attaching means for securing the flexible element to the filter.

Filter removal devices

A kit for forming an air filtering assembly from a portable box fan assembly having a parallelepiped housing with square open sides through which an electric motor driven fan in the housing propels air, and a filter assembly including a parallelepiped frame with opposite sides with through openings generally corresponding in size to the open sides of the housing of the box fan assembly and a sheet of air filtering material within the filter assembly frame between its sides. The kit includes (1) a plurality of clips or hooks; (2) a lengths of adhesive for adhering the clips or hooks to outer surfaces of side portions of the housing for the box fan assembly; and (3) a resiliently elastic cord adapted to extend through passageways in the clips or hooks and between the clips or hooks around the side of the filter assembly opposite the box fan assembly to retain the filter assembly along one of the sides of the housing of the box fan assembly.

Air filter assembly

The method of forming pleated filter media includes providing a generally planar web of filter material, folding the web to form a pleated web having a plurality of fold lines, arranging the plurality of pleats in a first spaced configuration defined by a first distance between adjacent pleat tips, applying a continuous strand of adhesive to the web, and adjusting the arrangement of the plurality of pleats into a second spaced configuration defined by a second distance between adjacent pleat tips. The web has a front face and a rear face. Each fold line is intermediate oppositely sloping first and second wall surfaces. The plurality of fold lines form a plurality of pleats having a first plurality of pleat tips and a second plurality of pleat valleys. The second distance is different from the first distance.

Method of forming self-supporting pleated filter media

A self-supporting, pleated filter, and method of making the same. The method includes forming a plurality of pleats in a filter media that extend along a front face and a rear face. The pleats include a plurality of pleat tips and sloping side surfaces generally perpendicular to the direction of pleating. At least one planar reinforcing strip oriented in the direction of pleating is bonded to the pleat tips on the front face. At least one reinforcing member is positioned along the rear face of the filter media. The filter media is then cut to size. Frame members are applied for some applications. The reinforcing member may be a reinforcing strip oriented in the direction of pleating and bonded to the rear face of the filter media prior to the step of forming the plurality of pleats. A second planar reinforcing strip may optionally be bonded to the reinforcing strip pleat tips. The reinforcing member, the first reinforcing strip and the second reinforcing strip can be aligned to form a truss structure. Alternatively, reinforcing strips oriented perpendicular to the direction of pleating are bonded to the rear face of the filter media prior to the step of forming the pleats. In another embodiment, a reinforcing member is applied to the rear face of the filter media after the pleats have been formed. The reinforcing member is positioned along at least one of the sloping side surfaces of the pleats on the rear face in a direction perpendicular to the direction of pleating. In another embodiment, a scrim is positioned along the rear face of the filter media. The scrim can be bonded to the frame members, the filter media and/or a portion of the frame members extend over a perimeter of the scrim to secure it to the pleated filter.

Method of making self-supporting pleated filter

Nonwoven webs having substantially aligned fibers can be formed in an apparatus having a direction of motion corresponding to the direction of web formation. The web is formed in the presence of at least one secondary fluid stream that oscillates the filaments or resulting attenuated fibers to and fro generally in and against the direction of motion so that a majority of the collected fibers are aligned within &#xb1;20&#xb0; of the direction of motion and fibers having lengths of about 1-10 cm can be teased from the web. The resulting nonwoven webs are especially useful for forming pleated filtration media having pleats generally transverse to the direction of motion.

Growing community of inventors

Hudson, WI, United States of America

Douglas C Sundet