Fibrous media
First Claim
1. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
- a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns;
an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber;
a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and
a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface,wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber;
wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron.
1 Assignment
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Accused Products
Abstract
A multi-faceted family of non-woven webs that can take the form of a filter media, an adaptable forming process and a machine capable of making the range of media are disclosed. The filter medium can have a first surface and a second surface defining a thickness. The medium can comprise a region having a gradient. Such a gradient is formed by having a medium wherein the concentration of a fiber, a property or other component varies from one surface to the next surface. The gradient region of the media can comprise the entire thickness of the medium or can comprise a region that comprises a portion of the media thickness. The media are characterized by the presence of a continuous change of the fiber concentration or property within the region. A non-woven web can also be made comprising a planar fiber structure having a gradient. Such a web can comprise fibers having diameters that can range from 1 to 40 microns and a second fiber having a diameter that can range from 0.5 microns to about 5 microns. The gradient can change in the cross machine (x-dimension) or across the thickness (z-dimension) increasing or decreasing in either direction. The media of the invention can be used in a variety of applications for the purpose of removing particulates from a variety of gas use on liquid media. Further, the filtered medium of the invention used in a variety of filter element types including flat media, pleated media, flat panel filters, cylindrical spin-on filters, z media pleated filters and other embodiments wherein the gradient provides useful properties. Methods or processes or an apparatuses for forming a nonwoven medium comprising controllable characteristic within the medium are disclosed. The term medium (plural media) refers to a web made of fiber having variable or controlled structure and physical properties.
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Citations
93 Claims
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1. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface, wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 27, 28)
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24. A filter selected from a flat panel filter, a cylindrical filter, a spin on filter or a z-media pleated filter wherein the filter comprises a nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and a spacer fiber different from the first fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface, wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5micron and less than or equal to 15 micron; andwherein the region has a pore size gradient from the bottom surface to the top surface. - View Dependent Claims (25)
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29. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface; wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron; andwherein the bicomponent fiber does not vary substantially in the region. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49)
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50. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface; wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron; andwherein the diameter of the efficiency fiber and the spacer fiber is less than 6 microns. - View Dependent Claims (51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67)
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68. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface; wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron; andwherein the medium has a pore size gradient from the bottom surface to the top surface. - View Dependent Claims (69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82)
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83. A nonwoven filter medium comprising a wet laid non-woven region derived from an aqueous furnish, the medium comprising:
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a bicomponent fiber comprising a first thermoplastic portion with a first melting point and a second thermoplastic portion with a lower melting point, the bicomponent fiber having a diameter of at least 1 and at most 40 microns; an efficiency fiber comprising glass and having a fiber diameter of at least 0.5 micron and at most 6 microns, wherein the bicomponent fiber is larger in diameter than the efficiency fiber; a spacer fiber, wherein the spacer fiber is larger in diameter than the efficiency fiber and smaller in diameter than the bicomponent fiber; and a bottom surface and a top surface defining a thickness, the region comprising a z-direction fiber gradient comprising a blend of bicomponent fiber, efficiency fiber, and spacer fiber, wherein the gradient comprises a concentration of the spacer fiber that either continually increases or continually decreases in a direction from the bottom surface to the top surface; wherein the medium comprises 30 to 85 wt % bicomponent fiber, 10 to 70 wt % efficiency fiber, and 2 to 45 wt % spacer fiber; wherein the medium is characterized by having a β
200 greater than or equal to 5 micron and less than or equal to 15 micron; andwherein the medium defines a thickness of 0.3 to 5 millimeter. - View Dependent Claims (84, 85, 86, 87, 88, 89, 90, 91, 92, 93)
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Specification