Arrangement for forming a layered fibrous mat of varied porosity
AssigneeAAF-McQuay Inc.
InventorKyung Choi
Life of this patent
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Abstract
An arrangement for producing a fibrous mat from a heated die source wherein the produced mat includes a first layered, preselected fiber portion of substantially straight fibers produced by directing such fibers directly to a collector source and a second layered preselected fiber portion of substantially curled fibers produced by diverting and exerting an external vortically creative curling force thereon before reaching the collector source.
Claims28
A mat of fibrous filter media comprising a downstream side having at least a first portion of meltblown fibers of selected fiber diameter and an upstream side having at least a second portion of meltblown fibers also of selected fiber diameter, said first portion of meltblown fibers and said second portion of meltblown fibers being continuously intermingled along a planar interface between said first portion and said second portion, said first portion and said second portion being formed of a single material, said first portion being formed of generally straight and substantially aligned fibers of a first selected porosity and said second portion being of substantially curled fibers of a second selected larger porosity than said first portion, at least one of said first and second portion of meltblown fibers having a fiber diameter of between about 0.3 microns and about 25 microns, wherein said mat of fibrous filter media has a fiber size gradient and gradient density and porosity through a depth dimension transverse to said planar interface.
A mat of layered fibrous filter media comprising at least a first downstream portion, a second upstream portion, and a third intermediate portion of continuously intermingled portions of meltblown fibers along a planar interface between a first portion and a second portion, said first, second and third portions being a single material and comprising a fiber size gradient defined by fibers of a first die row being comparatively fine, fibers of a second die row being comparatively medium and fibers of a third die row being comparatively course and with the meltblown fibers of one of said first, second and third portions having been attenuated directly in straight fibers formed from one of said first, second and third die rows to form comparatively denser, less porous layers of said final fibrous mat and the meltblown fibers of another of said first, second and third portions having been diverted and subjected to an external vortically creating force to form at least one layer of said final fibrous mat in curled form with greater porosity than another layer of said final fibrous mat and wherein said mat of fibrous filter media has a gradient density through a depth dimension.
A layered web of fibrous filter media comprising:
- at least one downstream layer having relatively straight meltblown fibers;
- and
- at least one upstream layer having curled meltblown fibers wherein said upstream layer has a porosity greater than a porosity of said at least one downstream layer having relatively straight fibers;
- at least one of said relatively straight meltblown fibers and said curled meltblown fibers having a fiber diameter of between about 0.3 and 25 microns, and said fibrous filter media having a fiber size gradient and a gradient density through a depth;
- said at least one upstream layer and said at least one downstream layer being continuously intermingled.
A mat of fibrous filter media comprising at least a first meltblown fiber portion of selected fiber diameter and at least a second meltblown fiber portion also of selected fiber diameter, said first and second meltblown fiber portions being continuously intermingled along a planar interface between said first and second meltblown portions, said first meltblown fiber portion being a downstream layer of substantially aligned and substantially straight fibers of a first selected porosity spun from a die source directly to a collector source and said meltblown second fiber portion being an upstream layer of substantially curled external vortically creating force treated fibers of a second selected larger porosity than said first portion due to said external vortically creating force treatment before arriving at said collector source to combine with said first portion in forming said continuously intermingled meltblown mat.
A mat of layered fibrous filter media comprising at least first and second portions of meltblown continuously intermingled fibers, said first layer being adjacent a downstream side of said mat, said second portion being adjacent an upstream side of said mat, said portions comprising approximately one third and two-thirds respectively of the final thickness of said layered fibrous mat with the meltblown fibers of both portions being approximately 3.5 microns in diameter and with the meltblown fibers of said first portion having been attenuated directly in straight fiber form from a die source to form comparatively denser, less porous layers of said final fibrous mat and the fibers of said second portion having been diverted and subjected to an external vertically creating force to form the layers of said second portion of mat in curled form with greater porosity than said layers of said first portion.
Dependencies are inferred from the claim text.