CA2682984C - Filter with eptfe and method of forming - Google Patents
Filter with eptfe and method of forming Download PDFInfo
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- CA2682984C CA2682984C CA2682984A CA2682984A CA2682984C CA 2682984 C CA2682984 C CA 2682984C CA 2682984 A CA2682984 A CA 2682984A CA 2682984 A CA2682984 A CA 2682984A CA 2682984 C CA2682984 C CA 2682984C
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- Prior art keywords
- fluid filter
- layer
- scrim
- support scrim
- media
- Prior art date
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- 238000000034 method Methods 0.000 title description 33
- 229920000295 expanded polytetrafluoroethylene Polymers 0.000 claims abstract description 77
- 239000000463 material Substances 0.000 claims abstract description 63
- 239000000155 melt Substances 0.000 claims abstract description 8
- 238000011144 upstream manufacturing Methods 0.000 claims abstract description 8
- 238000004519 manufacturing process Methods 0.000 claims abstract description 7
- 239000000835 fiber Substances 0.000 claims description 80
- 239000012530 fluid Substances 0.000 claims description 59
- 229920000728 polyester Polymers 0.000 claims description 52
- -1 polyethylene Polymers 0.000 claims description 28
- 238000002844 melting Methods 0.000 claims description 27
- 230000008018 melting Effects 0.000 claims description 27
- 239000004698 Polyethylene Substances 0.000 claims description 26
- 229920000573 polyethylene Polymers 0.000 claims description 26
- 239000002245 particle Substances 0.000 claims description 9
- 238000001816 cooling Methods 0.000 claims description 8
- 230000035699 permeability Effects 0.000 claims description 8
- 230000000149 penetrating effect Effects 0.000 claims description 7
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 57
- 238000010586 diagram Methods 0.000 description 14
- 239000002657 fibrous material Substances 0.000 description 8
- 239000011148 porous material Substances 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 230000008901 benefit Effects 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 239000012809 cooling fluid Substances 0.000 description 3
- 238000007373 indentation Methods 0.000 description 3
- 239000011800 void material Substances 0.000 description 3
- 102000004855 Multi drug resistance-associated proteins Human genes 0.000 description 2
- 108090001099 Multi drug resistance-associated proteins Proteins 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 229920001634 Copolyester Polymers 0.000 description 1
- 240000005979 Hordeum vulgare Species 0.000 description 1
- 235000007340 Hordeum vulgare Nutrition 0.000 description 1
- GXCLVBGFBYZDAG-UHFFFAOYSA-N N-[2-(1H-indol-3-yl)ethyl]-N-methylprop-2-en-1-amine Chemical group CN(CCC1=CNC2=C1C=CC=C2)CC=C GXCLVBGFBYZDAG-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 208000024780 Urticaria Diseases 0.000 description 1
- 230000001680 brushing effect Effects 0.000 description 1
- 238000009960 carding Methods 0.000 description 1
- 101150040681 cho1 gene Proteins 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000004890 malting Methods 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 238000009991 scouring Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 210000004722 stifle Anatomy 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D39/00—Filtering material for liquid or gaseous fluids
- B01D39/14—Other self-supporting filtering material ; Other filtering material
- B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
- B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
- B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
- B01D39/163—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin sintered or bonded
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/02—Types of fibres, filaments or particles, self-supporting or supported materials
- B01D2239/0216—Bicomponent or multicomponent fibres
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
- B01D2239/06—Filter cloth, e.g. knitted, woven non-woven; self-supported material
- B01D2239/065—More than one layer present in the filtering material
- B01D2239/0668—The layers being joined by heat or melt-bonding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1002—Methods of surface bonding and/or assembly therefor with permanent bending or reshaping or surface deformation of self sustaining lamina
- Y10T156/1007—Running or continuous length work
- Y10T156/1016—Transverse corrugating
- Y10T156/1018—Subsequent to assembly of laminae
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T156/00—Adhesive bonding and miscellaneous chemical manufacture
- Y10T156/10—Methods of surface bonding and/or assembly therefor
- Y10T156/1052—Methods of surface bonding and/or assembly therefor with cutting, punching, tearing or severing
- Y10T156/1082—Partial cutting bonded sandwich [e.g., grooving or incising]
Abstract
A filter media product and method of making the same wherein the filter media is pleatable and has at least one support scrim comprised of a melt bonded non-woven material or a fuse bonded non-woven material bonded to a layer of expanded polytetrafluoroethylene. The filter media may have a single support scrim with one or more layers and optionally may have a support scrim on both an upstream and downstream surface where both or neither support scrim is multilayered. The filter media may have an efficiency greater than, equal to, or less than HEPA.
Description
Gastle iasge System 0007/027 WO 2098/124417 t'CIYU32fi1t;lesgeeS
UTILITY PATENT APPLICATION
FOR
FILTER WITH RPM AND METHOD OF FORMING
BY
KYUNG-J1/ CHO1, A UNITED STATES CITIZEN, RESIDING AT
8406 RUNNING SPRING DRIVE, LOUISVILLE, KENTUCKY, 40241, USA
CROSS REFERENCE TO RELATED APPLICATIONS
[01) This application claims benefit of priority to U.S. Patent Application Serial Number 11/696,773, filed on April 5, 2007, now U.S. Patent Number 7,837,756, issued November 23, 2010.
FIELD OF THE INVENTION
[001) The present invention relates to filters, such as gas or air Stem and methods of forming filters.
BACKGROUND OF THE INVENTION
UTILITY PATENT APPLICATION
FOR
FILTER WITH RPM AND METHOD OF FORMING
BY
KYUNG-J1/ CHO1, A UNITED STATES CITIZEN, RESIDING AT
8406 RUNNING SPRING DRIVE, LOUISVILLE, KENTUCKY, 40241, USA
CROSS REFERENCE TO RELATED APPLICATIONS
[01) This application claims benefit of priority to U.S. Patent Application Serial Number 11/696,773, filed on April 5, 2007, now U.S. Patent Number 7,837,756, issued November 23, 2010.
FIELD OF THE INVENTION
[001) The present invention relates to filters, such as gas or air Stem and methods of forming filters.
BACKGROUND OF THE INVENTION
[002) It is known to provide filter media having a relatively high efficiency rating commonly referred to as a High Efficiency Particulate Air (HEPA, 99.97% efficient at a 0.3 pm particle size) by having expanded polytetrafluoroethylene (ePTFE) incorporated within the filter media.
However, the scrim or support materials used in making the ePTFE containing filter media have often caused a restriction of the process steps associated with malting the ePTFE filter media to prevent damage to the eFTFE during manufacturing and/or have typically not yielded desired filter media o istica such as pleatabiility or stiffness. Additionally, providing an ePTFE containing filter media having an efficiency less than HEPA, reducing the resulting pressure drop across the filter media, is often desiable.
Ma! 7127 = RCVD AT SM2120117:]2:07 AM P NOM DWAat TYWAj= adR:F0000]10 =
IMIMIN0' C110.1 703 es2 ON = DURA710N Owse*0040-Gastle Image System 008/027 WO 2008!124417 PCP/US20Q8le99085 SUMMARY
10031 The following presents a simplified summary of the foregoing disclosure to provide a basic understanding of some aspects of the invention.
This summary is not an extensive overview of the invention. It is not intended to restrict key or critical elements of the invention or to delineate the scope of the invention beyond that explicitly or implicitly described by the following description and claims.
[004J In an exemplary embodiment, there is provided a fluid filter which includes an upstream and downstream surface and is capable of obtaining a desirable minimum efficiency at a low pressure drop having a media comprising: a fast relatively open pleatable support scrim comprised of a melt bonded non-woven material or a fuse bonded non-woven material with greater than 40% bi-component fibers. The first support scrim has a Gurley stress of at least 500mg. A layer of expanded polytetrafluoroethylene is provided which has a first surface bonded to the first support scrim, and the media is also pleated and self-supporting.
(0051 In another exemplary embodiment, a fluid filter having a media is provided. The fluid filter comprises a pleatable first support scrim having a melt bonded non-woven material or a fuse bonded non-woven material. The first support scrim has a Gurley stiffiress of at least 500 mg. A layer of expanded polytetrafluwoethylene which has a first surface bonded to the first support scrim is also provided. The fluid filter media is pleated, self-supporting and with and having an efficiency greater than about 40% and less than 99.97% efficient at 0.3 micron.
[0061 In yet another exemplary embodiment then is provided a method of mating a fluid filter media. The method comprising feeding at least one support scrim to a heat roll, wherein the at least one support scrim is a melt bonded non-woven material or a fine bonded non-woven material; feeding expanded polytetrafluoroethyleue to the heat roll wherein the at least one support scrim contacts the expanded polytetrafluoroethylene; bonding the expanded polytetrafluororIlIylme to the at least one support scrim forming a layered filter media; passing the layered filter media through a cooling jet so as PAW $127 = RCVD AT 5112120117:32:07 AM tthst m DAM Thal'saa:Fcoaass =
DNSk30001 C$D:170$ 0a2 N74' DURATIaN ).=a$4s Gast.e Image 6peteme 110091027 WO 2008/124417 PCrNS2008/059085 to from a hardened multilayered filter media; and pleating the multilayered media.
10071 In another exemplary embodiment, a fluid filter media comprising at least one pleatable scrim layer with a Gurley stiffness of at least 500 mg bonded to an ePTFE layer is provided. The filter media has an efficiency of between about 70% and 90%. The at least one scrim layer has melt bonded non woven or but bonded non-woven bicomponent fibers.
10081 In some exemplary embodiments, the first support scrim is carded.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
10091 The figures herein disclose several embodiments of the present invention and are not to be interpreted as limiting the scope of the present invention.
10101 Figure IA is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroerhylene containing filter media having a first surface bonded to a first support scrim and a second surface bonded to a second support scrim.
10111 Figure 1 B is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroethylene containing filter media having a first surface bonded to a first support scrim.
10121 Figure IC is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroethylene containing filter media having a second surface bonded to a fast support scrim.
10131 Figure 2A is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with gear wheels in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIGS. lA-iC.
10141 Figure 2B is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with scoring wheels in the expanded PAG! 4127 = RCW AT 0112120117: 2:07 AM Dq t TM ur SVR P0oOOSK = D1aae00o0~ Csu 17O5 0i2N74 = DYRA1iN QnM-44):0640 Gastle Image Systems Q010/027 polytetrafluoroethylene containing filter media produced by the processes of FIGs. IA-1C.
[015] Figure 2C is a. side elevational view of a schematic flow diagram of equipment arranged to form pleats with alternative scoring wheels in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIG& IA-IC.
[016) Figure 2D is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with knives in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIGs. lA-1C.
[017] Figure 3 is a front view of the filter media produced by the processes of FIGs. lB and 1C having a portion of the layers separated.
[018] Figure 4 is a front view of the filter media produced by the process of FIG. I A having a portion of the layers separated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[019] It is to be understood that various changes can be made by one skilled in the art in one or more of the several parts and in one or more of the several steps in the apparatus and method disclosed herein without departing from the scope or spirit of the present invention.
[020] A filter media product and method of making the same is provided wherein the filter media is pleatable and has at least one support scrim comprised of a malt bonded non-woven material or a fuse bonded nom-woven material bonded to a layer of expanded polytetrafluoreethyleae. The filter media may have a single support scrim with one or more layers and optionally may have a support scrim on both an upstream and downstream surface where both or neither support scrim is multilayered. The filter media may have an efficiency greater than, equal to, or less than HEPA.
[021] A filter media is provided having an ePTFE layer bonded to at least one scrim layerr. Typically, when achieving a desired efficiency for residential or other non-industrial applications, a resulting pressure drop across the filter media is too high for such applications. Embodiments disclosed herein MOE 11127 = NCVD AT 511muii 7a2 07A111 !u n O~q'U 4 Tne = SVR POOII S= DI
;3000 = CSU:1 703 002 5071.OYRATIOU plm4*N4o' Gastle image systems 011 OZ7 provide an acceptable pressure drop across the filter media for such non-industrial applications. It has been surprisingly found that a filter media having a carded pleatable scrim and efficiency between about 70% and 90%, advantageously approximately 80%, may have a pressure drop across the filter media of up to S0% less, or even more, than a traditional filter of similar efficiency. In one aspect, a pleatable self supporting filter media is comprised of staple fibers, providing a cost benefit over the use of spun-laid fibers.
Advantageously, the filter media has at least one carded self supporting scrim layer wherein carding of the fibers is accomplished by combing, brushing, or by other means providing substantially aligned fibers.
10221 Figure 1A shows schematic flow diagram 100 producing an expanded polytetrafluoroethylene containing filter media 34. Lower scrim supply roll 26 feeds a first scrim material 24 onto guide roller 22 which guides first scrim material 24 onto heated bonding roller 28. Optionally, sprayer 33 applies a powdered polymeric material such as polyethylene to an inner surface of first scrim material 24. Alternatively, the powdered polymeric material could be applied to lower surface of porous ePTFE film 10, The application of the powdered polymeric material provides bonding between porous ePTFE film 10 and the support scrim when such bonding is desirable.
Upper scrim supply roll 20 feeds a second scrim material 16 onto guide roller 18 which guides second scrim material 16 between guide roller 14 and nip roller 12. A porous ePTFE film or sheet 10 is fed between guide roller 14 and nip roller 12 and has a first and second surface wherein the second surface becomes adjacent second support scrim 16 at guide roller 14. Optionally, sprayer 35 applies a powdered polymeric material such as polyethylene to the second surface of porous ePTFE film 10, or alternatively to the surface of scrim material 16 that contacts porous ePTFE film 10. Both second support scrim 16 and porous ePTFE film 10 are fed adjacently onto heated bonding roller 28 wherein the first surface of porous ePTFE film 10 contacts firyt support scrim 24. For a portion of a revolution of heated bonding roller 28, first support scrim 24 is in contact with heated bonding roller 28 and the first surface of porous ePTFE film 10 and second support scrim 16 contacts the second surface of porous ePTFE film 10 wherein at least portions of first PA=1U27 = RCVDAT snsuo117:32:07AM t<a*ra Dayaalr TSaat= $W POOa51M5' DMS:3o05 = CW:1 7 552 5074.OURATIOm lan.w) 0640 Gastle i.age Systess ~O1Z/OZ7 WO 20081124417 PCINS200$f0Sl08S
support scrim 24 and second support swim l6 are partially melted or softened to an extent to provide a bond to porous ePTFE film 10. Shortly after exit of bonded first support scrim 24, porous *PTFE film 10, and second support scrim 16 from heated bonding roller 28 the composite passes by cooling jet 30.
Typically, cooling jet 30 supplies cool air or other cooling fluid to fluid cool the composite of first support scrim 24, porous ePTFE film 10, and second support scrim 16 to a point where the softened or partially melted portions of fast support scrim 24 and second support scrim 16 are hardened to form a multilayer filter media 34. Media 34 comprises porous e?TTE film 10 in a middle layer between first support scrim 24 and second support scrim 16. A
guide roller 32 is positioned so that media 34 is deflected, upon exit from roller 28, in such a way that it maintains a desired length of contact with the cucumhhfetaace of heated bonding roller 28 to properly bond feat support scrim 24, porous ePTFE film 10, and second support scrim 16 to form muitilayered filter media 34 and also serves to guide multilayer filter media 34 to a snbeegelent planting zone.
[0231 In one embodiment, Bust support scrim 24 and/or second support scrim 16 are comprised of carded non-woven fibrous materials such as melt bonded non-woven material or Elise bonded carded non-woven, materials. The use of carded non-woven fibrous materials provide a cost advantage over the use of other non-woven and woven fibrous materials. Advantageously, multilayer filter media 34 has sufficient structure to be self supporting.
Multilayer filter media 34 may have a barley stiffness of at least S00 mg, 10241 First support scrim 24 and/or second support scrim 16 may have single component fibers, bicomponent fibers, or a mixture of both single component fibers and bicomponart fibers. In a preferred esnbod sent, first support scrim 24 and/or second support scrim 16 have bicomponeot fibers in a range of 30% to 100% with the remainder being single coupovent fibers. The bioomponemt fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. First support scam 24 and/or second support scrim 16 may be multilaye ed with a first and second layer where the first layer is bonded to porous CPTFE film 10 and the second layer is bonded to PAR 12127 = MOAT V1212011 rna si *M psi .tn Oaya~eh Tea114= svlee'ooem = ens see eso 700 442084 = eresY-11011 aaRagseN
tiastie image'-spates 10013/027 WO 3005/134117 PC FIVS2000#OS9016 the first layer. In one embodiment of a multileyered scrim, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer has bioomponent fibers with a polyester and a oo-polyester. In the process of bonding first support scrim 24 and second support swim 16 to porous ePTFE
film 10 as described above, at least a portion of the fibers in each scum layer are partially melted or softened to an extent which will provide the desired bond to film 10.
(0251 Typically, porous ePTFE film 10 has much smaller pores or void spaces than either support scrim 24 or second support series 16. Thus, it is the size of the pores in porous ePTFE film 10 which typically defines the efficiency of multilayer filter media 34, wherein the efficiency is the percentage of particles over a given size that are filtered out of a gas stream passed thetethrough However, in the instances wherein filter media 34 has a lower efficiency (<-- HEPA), the scam may define the efficiency of filter media 34. The size of the pores in porous ePTFE film 10 is proportional to the extent of expansion or stretching of porous ePTFE film 10. Typically, porous ePTFE film 10 is sequentially stretched, longitudinally then latitudinally, to an extent as to provide a desired efficiency of filter media 34. However, porous ePTFE film 10 may be expanded to an extant wherein the pore size therein is larger than the pore size of either support scrim 24. Filter media 34 may have an efficiency of at most 99.97% at 0.3p (< HEPA), or of at least 99.97% at 0.3g (" HEPA), greater than about 40% and less than IfEPA, or in a range of 40% to 99.999995% (ULPA) at a most penetrating particle size. Filter media 34 may have efficiency between. about 70% and 90%, advaotageoualy approxim lely 80%. Typically, filter media 34 has permeability in a range of 2 to 400 cf ntsq ft as measured with an air permeability measuring instrument, such as a Frazier, Te xtest, or other instrmment as known in the art.
1026) Figure lB shows schematic flow diagram 200 of an apparatus for producing an expanded polytettatluorodhylene containing filter media 40.
Lower scrim supply ro1126 feeds a scrim material 24 onto guide roller 22 which guides scrim material 24 onto heated bonding roller 28. A porous ePTFE film or sheet 10 is fed between guide roller 14 and amp roller 12 and has a first and. second surface wherein the first surface of porous ePTFE film 10 PA a 13137' R C Y D A T 1112120117:301 AM FwtNn D g j W 1 iu' svkrrONas' OIM:0000' Cap:1700 60 Will DU ATION 5%vn4$):0000 r unssie ima~a o~asemr W021151124417 ICT,X717 becomes adjacent support scrim 24 on heated bonding roller 28. Optionally, sprayer 33 applies a powdered polymeric material such as polyethylene to an inner surface of first scrim material 24, or alternatively to lower surf ce of porous cPTFE film 10. For a portion of a revolution of heated bonding roller 28, support scrim 24 comes into contact with hated bonding roller 28 and the first surface of porous ePTFE film 10, wherein at least a portion of the fibers in support scrim 24 are partially melted or softened to an extent to provide a bond to porous ePTFE film 10. Shortly after exit of bonded support scrim 24 and porous ePTFE film 10 from heated bonding roller 28, the composite passes by cooling jet30. Typically, cooling air jet 30 supplies cool air or other cooling fluid to cool the composite of support scrim 24 and porous ePTFE film 10 to a point where the softened or melted portions of support scrim 24 are hardened forming multilayer filter media 40 having porous ePTFE film 10 bonded to support scrim 24. Guide roller 32 is positioned so that media 40 is deflected in such a way upon exit from roller 28 that it maintains a desired lmg& of contact with the circumference of heated huller 28 to bonding properly bond support scrim 24 and porous ePTFE film 10 to form multilayer filter media 40, and also serves to guide multtilayer filter media 40 to a subsequent pleating zone.
[0271 Advantageously, support scrim 24 is comprised of carded non-woven fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Filter media 40 may have sufficient structure to be self supporting and advantageously bra a Gurley stifl'neas of at least 500 mg. Support scrim 24 may have single component fibers, bioomponent fibers, or a mixture of both single component fibers and bicomponent fibers. In a prefaced embodiment, support scrim 24 has bicomponent fibers in a range of 30% to 100% with the remainder being single component fibers. In a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or oopolyeater. Support scrim 24 may be multilayered with a first and second layer where the first layer is bonded to porous OPTFE film 10 and the second layer is bonded to the first layer. In one embodiment of a multilayered scum, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer PAeha 14 7 = RCVD AT 511 212 0 1 1 T:3210T AM ¾..*.m DIyaaat Ti1Nt' sva:Reooesf0' Dt1a:5000"Can:1700 a 5074.0( ATlON tin ss):0540 i~asaie iasge bpseei~s 0015/027 WO x01 /134117 PCT/US211W0S9NS
has bicomponent fibers with a polyester and a co-polyester. Filter media 40 may have an efficiency of at most 99.97% at 0.3p (<- HEPA), at least 99.97%
at 0.3ir (> HEPA), greater than about 40% and loss than HEPA, or in a range of 40% to 99.999995% at a most penetrating particle size. Typically, filter media 40 has a permeability in a range of 2 to 400 cfin/aq lt. Advantageously, fitters media 40 has sufficient structure to be self supporting with a Gurley stiffness of at least 500 mg.
! [028] Figure 1C shows schematic flow diagram 300 producing an expended polytetrafluoroelhylene containing filter media 50. Upper sorim supply roll 20 feeds a scrim material 16 onto guide roller 18 which guides acrim material 16 between guide roller 14 and nip roller 12. A porous ePTFE
film or sheet 10 is fed between guide roller 14 and nip roller 12 and has a first and second surface wherein the second surface becomes adjacent support scrim 16 at guide roller 14. Optionally, sprayer 35 applies a powdered polymeric material such as polyethylene to the second surface of porous ePTFE film 10, or alternatively to the surface of scorn material 16 that contacts pomve ePTPE
flat 10. Both ncport scrim 16 and porous eP TFE film 10 are fed adjacently onto heated bonding roller 28 wherein the Bast surface of porous ePTFE film becomes adjacent hated bonding roller 28. For a portion of a revolution of boated bonding roller 28, the first surface of porous eFTFE film 10 is adjacent heated bonding roller 28 and support swim 16 is adjacent the second surface of porous ePTPE film 10 wherein at least a portion of the, fibers in support scrim 16 are partially melted or softened to an extent to provide a bond to porous ePTFE Min 10. Upon separation of porous ePTFE film 10 and support scrim 16.firom heated bonding roller 28 is ooohng jet 30. Typically, cooling jet 30 supplies cool air or other cooling fluid cooling porous ePTFE film 10 and support scrim 16 to a point when the softened or partially milted portions of support scrims 16 are hardened forming filter media 50 having porous ePTFE
film 10 and support scrim 16. Guide roller 32 is positioned about heated bonding roller 28 to provide a desired contacting circumference of boated bonding roller 28 with porous eYTFE film 10 and support elm 16 and to guide filter media 50 to a pleating zone.
=
PAGE 1527' MOAT ev191AO11 T:32.T AM pMO m DwyWTW4 a roosssu' DMa"MOs' cm1706 us sin' D{MTIOM ern ss) Mirr ~ast.e renege Bylte. J1016/027 [0291 Advantageously, support scrim 16 is comprised of carded now-woven fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Advantageously, filter media 50 has sufficient structure to be self supporting and more advantageously has a Curley stifs of at least 500 rag. Support scrim 16 may have single component fibers, bieomponeut fibers, or a mixture of both single component fibers and bicomponent fibers. In a preferred embodiment, support scrim 16 has bicomponent fibers in a range of 30% to 100% with the remainder being single component fibers. In a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. Support scrim 16 is optionally multilayered with a first and second layer where the first layer is bonded to porous ePTFE film 10 and the second layer is bonded to the first layer. In one en*odnoraut of a multilaye ed scrim, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer bas bicomponent fibers with a polyester and a co-polyester. Filter media 50 may have an efficiency of at most 99.97% at 0.3 (<' HEPA), at least 99.97%
at 0.3 L (x HEPA), greater Wan about 4006 and lees than HEPA, or in a range of 40% to 99.999995% (ULPA) at a most penetrating particle size. Typically,' filter media 50 has a permeability in a range of 2 to 400 afm/sq ft.
[0361 Figure 2A shows a sclwmatic flow diagram of process 400 arranged to form pleats in the expanded polytetrafluoroethylene containing fitter media 410 produced by the processes of PIQs. IM C or the like. This method includes the steps of heeding a longitudinally extending continuous flat skeet of porous filter media 410 from a supply zone or directly from a process of making such as disclosed in FiGs. IA-1C. Porous filter media 410 can be any one of several materials as above described, inch rdiwg CPTPE with a single scrim, single or multi layyer~eed, or a scrim material joined to a first and second surthce when the second scrim may be single or multilayercd. Filter media 410 is fed between a per of cooperating gear pleating wheels 420 and 430 each having a star shaped periphery. The periphery of gears 420 and 430 cooperate to respectively engage filter media 410 to form valleys and crests in filter media 410 to produce pleated filter media 440. Optionally, filter media 440 can be heated to aid in the formation of fixed valleys and crests do6niag PA0a 1W27 - RCVD AT 0M2r30117:32:07 AM $uarn W 4M TUnar- avR:FOOos3I =
Craa:000 = Cap:170b 40 0514 - DURAUON 41nrss):0540 usatte xaage ayste>r Q0017/027 WO 2505(124417 PCTIUS20NnS9ISS
pleats in pleated filter media 440. Heating can be accomplished by heating upper gear 420 and lower gear 430, with heat plates 414, or both. Filter media 440 than is fed on an appropriate endless belt conveyor 450 moving at a preselected speed, a sower speed than the speed at which filter media 410 is fed to between gears 420 and 430. Filter media 440 conveyed thereto is caused to fold into a plurality of pleats, providing the aforementioned crests and valleys.
[031) Figure 2B shows a schematic flow diagram of process 500 arranged to form pleats in the expanded poly tetrafluomethylene containing filter media 510 produced by any one of the processes of FKIS. WIC or the like. This method includes the stela of feeding a longitudinally extending contimroas flat sheet of porous filter media 510 from a supply zone or directly from a process of making such as disclosed in FIGs. lA-IC. Porous fitter media 510 can have ePTFE with a single scrim, single or multi layered, or a scrim material joined to a first and second surface where the second scrim maybe single or mahilayered. Filter media 510 is fed between a pair of cooperating scouring wheels 520 and 530, each having a periphery with at least one "V" shaped indentation and at least one "V" shaped projection. The at least one indentation in upper soonag wheel 520 cooperates with the at least one projection in lower scoring wheel 530 and the at least one projection in upper scoring wheel 520 cooperates with the at least one indentation in lower scoring wheel 530 for each rotation of scoring wheels 520 and 530. Optionally, filter media 540 can be heated to aid in the formation of transversely extending score lines in filter media 510. Heating can be accomplished by heating upper scoring wheel 520 and lower scoring wheel 530, with beat plates 514, or both.
Filter media 540 then is fed on an appropriate endless belt conveyor 550 moving at a preselected speed, a slower speed than the speed at which filter media 510 is fed to between scoring wheels 520 and 530. Filter media 540 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys.
[0321 Figure 2C shows a schematic taw diagram of process 600 arranged to form pleats in the expanded polyte t atluoroe hyiene containing filler media 610 produced by any one of the processes of FIGs. IA-1C or the like. This PACE 17127' RCYD AT 611212011 7:52:67 AM AMMm DMV TI I$" NR:PD06621r "
01111:3101' cac:1 701 662 0074' D{IRATIDR anwn uu):0546 wesie image systems 0018/027 WO 2008/124417 PCT/US2NWI5N$5 method includes the steps of feeding a longitudinally extending continuous flat sheet of porous filter media 610 from a supply zone or directly from a process of making such as disclosed in FIGs. IA-IC. Porous filter media 610 can have ePTFE with a single scrim, single or multi layered, or a scrim material joined to a first and second surface where the second scrim may be single or multilayered. Filter media 610 is fed between a pair of cooperating scoring wheels 620 and 630, each having a periphery with at least one projection.
Advantageously, the at least one projection in upper scoring wheal 620 cooperates with a pliable or softened material in lower scoring wheel 630 and the at least one projection in lower scoring wheel 630 cooperates with a pliable or softened material in upper scoring wheel 620 for each rotation of scoring wheels 620 and 630. Optionally, filter media 640 can be heated to aid in the formation of transversely extending score lines in filter media 640. Heating can be accomplished by heating upper scoring wheel 620 and lower scoring wheel 630, with heat plates 615, or both. Scored filter media 640 then is fed onto an appropriate endless belt conveyor 650 moving at a preselected speed, a slower speed than the speed at which filter media 610 is fed to between scoring wheels 620 and 630. Filter media 640 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys. It is to be understood that the geometry and configuration of the scores can be varied providing desirable pleat crests, valleys, and flanks.
[0331 Figure 2D shows a schematic flow diagram of process 700 arranged to form pleats in the expanded polytetrafluoroethylene containing filter media 710 produced by any one of the processes of FIGS. IA-IC or the like. This method includes the steps of feeding a longitudinally extending continuous flat sheet of porous filter media 710 from a supply zone or directly from a process of making such as disclosed in FIGS. IA-1C. Porous filter media 710 can have ePTFE with a single soling, single or multi layered, or a scrim material joined to a first and second surface where the second scrim maybe single or multilayered. Filter media 710 is fed between a pair of reciprocating knives 720 and 730, offset firm one another and transversely extending filter media 710. Suitably spaced knivea720 and 730 on opposed surfaces of filter media 710 serve to score and plat the flat sheet of filter media 710 in longitudinally PAGE 14127' RCVD AT 3117120117:22:07 AM B4utsm D.yugtd TMI4' avR:FOOI0 S' DNa:3000' C4a1:1 700 442 4074' DURATION $m , ):0440 Castle image System 0019/027 WO 2$0W124417 PCTNS200wsSloes spaced, transversely extending lines as media 710 is passed therethrough with longitudinally spaced score lines extending transversely between the opposed, spaced longitudinally extending edges of filter media 710 and with the longitudinally spaced score lines on one face of filter media 710 being offset from the score lines on the other or opposite face of filter media 710.
Advantageously, reciprocating knives 720 and 730 are heated to aid in the formation of transversely extending score lines in filter media 710, with heat plates 715, or both. Scored filter media 740 then is fed onto an appropriate endless belt conveyor 750 moving at a preselected speed, a slower speed than the speed at which filter media 710 is fed to between scoring knives 720 and 730. Filter media 740 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys. It is to be understood that other types of apparatus can be employed in addition to those schematically disclosed herein to accomplish the novel steps herein described.
[034] Figure 3 shows filter media 800 produced by the processes of FIGs.
lB and IC or the like having a portion of the layers separated. Filter media 800 has a layer of porous ePTFE film 830 with a first scrim on a first surface.
The first scrim shown here is a multilayer scrim having layers 820 and 810.
Advantageously, first support scrim layers 810 and 820 are comprised of carded non-woven fibrous materials such as melt bonded carded non woven material or fuse bonded carded non-woven materials. Advantageously, filter media 800 has sufficient structure to be self supporting and has a Gsrley stiffness of at least 500 mg. Support scrim layers 810 and 820 may have single {
component fibers, bicomponent fibers, or a mixture of both single component fibers and bicomponent fibers. In one embodiment, scrim layers 810 and 820 have bicamponent fibers in a range of 30% to 100% with the zemahxUr being single component fibers. The bicomponent fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. In a preferred embodiment of the multilayered scxirn, layer 820 has bicomponent fibers with a polyester and a polyethylene and layer 810 has biccomponent fibers with a polyester and a copolyester.. Embodiments of filter media 800 having a higher efficiency, porous ePTFE film 830 has much smaller pores or PAse 10!11' MCVD AT WM21101I 1:32:07 AM RptMl DsyII * TMJNp = IVR:P00003Ji =
DNIi:3001 = Cen:1 706 N2 0074 = DUMTNhN erln4s):0640 Gastle image Systems BOZO/027 WO 20011124417 PCT/US200010590i5 void spaces than both scrim layers 820 and 810. Thus, the mutest of expansion or stretching of porous ePTFE film 830 is proportional to the efficiency of filter media NO. Embodiments of filter media 800 having a lower efficiency, scrim layers 820 and 810 may have a smaller pore size than ePTPE film 830 and define the efficiency of fitter media 34. Filter media 800 may have an efficiency of at most 99.97% at 0.311(c- HEPA), at least 99.97% at 0.3p (>
HEPA), greater than about 40% and less than HEPA, or in a cargo of 40% to 99.999995% at a most penetrating particle size, depending upon the desired application of filter media 800. Typically, filter media 800 has a permeability in a range of 2 to 400 cfmJsq ft 10351 Scrim layers 820 and 810 maybe either on an upstream or downstream surface of ePTFE layer 830. Having scrim layers 820 and 810 on an upstream surface provides for a thickness having void spaces which increases the holding capacity of filter media 800. Conversely, having scrim layers 820 and 810 on a downstream surface provides for the ability to clam filter media 800 by back pulsing or shaking. Back pulse cleaning is accomplished by temponwily reversing the flow of the fluid passing through filter media 800 to dislodge accumulated material from ePTFE layer 830.
Alternatively or additionally, fiber media 800 may be shaken to dislodge accumulated material from ePTFE layer 830. Shaking and/or back pulsing are effective cleaning methods when scrim )ayes 810. and 820 are on a downstream surface since the accumulated materials are relatively readily separated from ePTFE membrane 830 with ePTFE's low propensity to stick to or hold the accumulated materials. The enhanced pleanability allows filter 800 to be repeatedly cleaned.
[036) Figure 4 shows films media 900 produced by the process of FIG. IA
or the like having a portion of the layers separated. Filter media 900 has a layer of porous uuPTFE film 930 with a first scrim on a first surface and a second scrim on a second surf.ace. The first scrim shown here is a multrlayer scrim having layers 920 and 910. Advaubgeously, first support scrim layers 910 and 920 are comprised of carded non-woven fibrous materials sorb as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Second support scrim 940 is comprised of carded non-woven PAGE21i27"RCYDAT3I12120117:fI:O7AMPriamDWIWTWgoaVR ROQ
IO3N=DDa.3ON=C$D:17Ne20OF4.OIIOATIONp,m S$Asm Gaatle image systems Q021/027 WO 2008/124417 PC1/US2008/m9185 fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Even though second support scrim 940 is shown as having a single layer it is to be understood that second support scrim 940 may be multilayered and may be comprised of the same or different materials as the first support scrim having layers 920 and 910.
Advantageously, filter media 900 has sufficient structure to be self supporting and a Gurley stiffiress of at least 500 mg. Support scrim layers 910,920 and 940 may have single component fibers, bicomponent fibers, or a mixture of both single component fibers and bioomponent fibers. In one embodiment, scrim layers 910 and 920 have bicomponent fibers in a range of 30% to 100 /6 with the remainder being single component fibers. The bicomponent fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. In a preferred embodiment of the multilaye ed scrim, layer 920 has bicomponent fibers with a polyester and a polyethylene and layer 910 has bicomponent fibers with a polyester and a co-polyester. In a preferred embodiment of the single layered scrim 940, layer 940 has bieomponent fibers with a polyester and a polyethylene. Filter media 900 may have an efficiency of at most 99.97% at 0.3g (< HEPA), at least 99.97% at 03p (> HEPA), greater than about 40% and less than HEPA, or in a range of 40% to 99.999995% at a most penetrating particle size, dependiaig upon the desired application of filter media 900. Typically, filter media 900 has a permeability in a range of2to400cfnfsgft.
(0371 While the present invention has been shown and described herein in what are considered to be the preferred embodiments thereof:, illustrating the results and advantages over the prior an obtained through the present invention, the invention is not limited to those specific embodiments. Thus, the forms of the invention shown and described herein are to be taken as illustrative only and other embodiments may be selected without departing from the scope of the present invention, as set forth in the claims appended hereto.
PAM 21W I RCW AT SM2120117:32:07 AM PYEwn D M Tti.q = $VR POOII = DNa:3100 =
Cn:1 100 002 0q4 = DU1117r0R õ :06x0 _ _._ ......_. ...._._. _..
However, the scrim or support materials used in making the ePTFE containing filter media have often caused a restriction of the process steps associated with malting the ePTFE filter media to prevent damage to the eFTFE during manufacturing and/or have typically not yielded desired filter media o istica such as pleatabiility or stiffness. Additionally, providing an ePTFE containing filter media having an efficiency less than HEPA, reducing the resulting pressure drop across the filter media, is often desiable.
Ma! 7127 = RCVD AT SM2120117:]2:07 AM P NOM DWAat TYWAj= adR:F0000]10 =
IMIMIN0' C110.1 703 es2 ON = DURA710N Owse*0040-Gastle Image System 008/027 WO 2008!124417 PCP/US20Q8le99085 SUMMARY
10031 The following presents a simplified summary of the foregoing disclosure to provide a basic understanding of some aspects of the invention.
This summary is not an extensive overview of the invention. It is not intended to restrict key or critical elements of the invention or to delineate the scope of the invention beyond that explicitly or implicitly described by the following description and claims.
[004J In an exemplary embodiment, there is provided a fluid filter which includes an upstream and downstream surface and is capable of obtaining a desirable minimum efficiency at a low pressure drop having a media comprising: a fast relatively open pleatable support scrim comprised of a melt bonded non-woven material or a fuse bonded non-woven material with greater than 40% bi-component fibers. The first support scrim has a Gurley stress of at least 500mg. A layer of expanded polytetrafluoroethylene is provided which has a first surface bonded to the first support scrim, and the media is also pleated and self-supporting.
(0051 In another exemplary embodiment, a fluid filter having a media is provided. The fluid filter comprises a pleatable first support scrim having a melt bonded non-woven material or a fuse bonded non-woven material. The first support scrim has a Gurley stiffiress of at least 500 mg. A layer of expanded polytetrafluwoethylene which has a first surface bonded to the first support scrim is also provided. The fluid filter media is pleated, self-supporting and with and having an efficiency greater than about 40% and less than 99.97% efficient at 0.3 micron.
[0061 In yet another exemplary embodiment then is provided a method of mating a fluid filter media. The method comprising feeding at least one support scrim to a heat roll, wherein the at least one support scrim is a melt bonded non-woven material or a fine bonded non-woven material; feeding expanded polytetrafluoroethyleue to the heat roll wherein the at least one support scrim contacts the expanded polytetrafluoroethylene; bonding the expanded polytetrafluororIlIylme to the at least one support scrim forming a layered filter media; passing the layered filter media through a cooling jet so as PAW $127 = RCVD AT 5112120117:32:07 AM tthst m DAM Thal'saa:Fcoaass =
DNSk30001 C$D:170$ 0a2 N74' DURATIaN ).=a$4s Gast.e Image 6peteme 110091027 WO 2008/124417 PCrNS2008/059085 to from a hardened multilayered filter media; and pleating the multilayered media.
10071 In another exemplary embodiment, a fluid filter media comprising at least one pleatable scrim layer with a Gurley stiffness of at least 500 mg bonded to an ePTFE layer is provided. The filter media has an efficiency of between about 70% and 90%. The at least one scrim layer has melt bonded non woven or but bonded non-woven bicomponent fibers.
10081 In some exemplary embodiments, the first support scrim is carded.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
10091 The figures herein disclose several embodiments of the present invention and are not to be interpreted as limiting the scope of the present invention.
10101 Figure IA is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroerhylene containing filter media having a first surface bonded to a first support scrim and a second surface bonded to a second support scrim.
10111 Figure 1 B is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroethylene containing filter media having a first surface bonded to a first support scrim.
10121 Figure IC is a side elevational view of a schematic flow diagram of equipment arranged to carry out steps to produce an expanded polytetrafluoroethylene containing filter media having a second surface bonded to a fast support scrim.
10131 Figure 2A is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with gear wheels in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIGS. lA-iC.
10141 Figure 2B is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with scoring wheels in the expanded PAG! 4127 = RCW AT 0112120117: 2:07 AM Dq t TM ur SVR P0oOOSK = D1aae00o0~ Csu 17O5 0i2N74 = DYRA1iN QnM-44):0640 Gastle Image Systems Q010/027 polytetrafluoroethylene containing filter media produced by the processes of FIGs. IA-1C.
[015] Figure 2C is a. side elevational view of a schematic flow diagram of equipment arranged to form pleats with alternative scoring wheels in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIG& IA-IC.
[016) Figure 2D is a side elevational view of a schematic flow diagram of equipment arranged to form pleats with knives in the expanded polytetrafluoroethylene containing filter media produced by the processes of FIGs. lA-1C.
[017] Figure 3 is a front view of the filter media produced by the processes of FIGs. lB and 1C having a portion of the layers separated.
[018] Figure 4 is a front view of the filter media produced by the process of FIG. I A having a portion of the layers separated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[019] It is to be understood that various changes can be made by one skilled in the art in one or more of the several parts and in one or more of the several steps in the apparatus and method disclosed herein without departing from the scope or spirit of the present invention.
[020] A filter media product and method of making the same is provided wherein the filter media is pleatable and has at least one support scrim comprised of a malt bonded non-woven material or a fuse bonded nom-woven material bonded to a layer of expanded polytetrafluoreethyleae. The filter media may have a single support scrim with one or more layers and optionally may have a support scrim on both an upstream and downstream surface where both or neither support scrim is multilayered. The filter media may have an efficiency greater than, equal to, or less than HEPA.
[021] A filter media is provided having an ePTFE layer bonded to at least one scrim layerr. Typically, when achieving a desired efficiency for residential or other non-industrial applications, a resulting pressure drop across the filter media is too high for such applications. Embodiments disclosed herein MOE 11127 = NCVD AT 511muii 7a2 07A111 !u n O~q'U 4 Tne = SVR POOII S= DI
;3000 = CSU:1 703 002 5071.OYRATIOU plm4*N4o' Gastle image systems 011 OZ7 provide an acceptable pressure drop across the filter media for such non-industrial applications. It has been surprisingly found that a filter media having a carded pleatable scrim and efficiency between about 70% and 90%, advantageously approximately 80%, may have a pressure drop across the filter media of up to S0% less, or even more, than a traditional filter of similar efficiency. In one aspect, a pleatable self supporting filter media is comprised of staple fibers, providing a cost benefit over the use of spun-laid fibers.
Advantageously, the filter media has at least one carded self supporting scrim layer wherein carding of the fibers is accomplished by combing, brushing, or by other means providing substantially aligned fibers.
10221 Figure 1A shows schematic flow diagram 100 producing an expanded polytetrafluoroethylene containing filter media 34. Lower scrim supply roll 26 feeds a first scrim material 24 onto guide roller 22 which guides first scrim material 24 onto heated bonding roller 28. Optionally, sprayer 33 applies a powdered polymeric material such as polyethylene to an inner surface of first scrim material 24. Alternatively, the powdered polymeric material could be applied to lower surface of porous ePTFE film 10, The application of the powdered polymeric material provides bonding between porous ePTFE film 10 and the support scrim when such bonding is desirable.
Upper scrim supply roll 20 feeds a second scrim material 16 onto guide roller 18 which guides second scrim material 16 between guide roller 14 and nip roller 12. A porous ePTFE film or sheet 10 is fed between guide roller 14 and nip roller 12 and has a first and second surface wherein the second surface becomes adjacent second support scrim 16 at guide roller 14. Optionally, sprayer 35 applies a powdered polymeric material such as polyethylene to the second surface of porous ePTFE film 10, or alternatively to the surface of scrim material 16 that contacts porous ePTFE film 10. Both second support scrim 16 and porous ePTFE film 10 are fed adjacently onto heated bonding roller 28 wherein the first surface of porous ePTFE film 10 contacts firyt support scrim 24. For a portion of a revolution of heated bonding roller 28, first support scrim 24 is in contact with heated bonding roller 28 and the first surface of porous ePTFE film 10 and second support scrim 16 contacts the second surface of porous ePTFE film 10 wherein at least portions of first PA=1U27 = RCVDAT snsuo117:32:07AM t<a*ra Dayaalr TSaat= $W POOa51M5' DMS:3o05 = CW:1 7 552 5074.OURATIOm lan.w) 0640 Gastle i.age Systess ~O1Z/OZ7 WO 20081124417 PCINS200$f0Sl08S
support scrim 24 and second support swim l6 are partially melted or softened to an extent to provide a bond to porous ePTFE film 10. Shortly after exit of bonded first support scrim 24, porous *PTFE film 10, and second support scrim 16 from heated bonding roller 28 the composite passes by cooling jet 30.
Typically, cooling jet 30 supplies cool air or other cooling fluid to fluid cool the composite of first support scrim 24, porous ePTFE film 10, and second support scrim 16 to a point where the softened or partially melted portions of fast support scrim 24 and second support scrim 16 are hardened to form a multilayer filter media 34. Media 34 comprises porous e?TTE film 10 in a middle layer between first support scrim 24 and second support scrim 16. A
guide roller 32 is positioned so that media 34 is deflected, upon exit from roller 28, in such a way that it maintains a desired length of contact with the cucumhhfetaace of heated bonding roller 28 to properly bond feat support scrim 24, porous ePTFE film 10, and second support scrim 16 to form muitilayered filter media 34 and also serves to guide multilayer filter media 34 to a snbeegelent planting zone.
[0231 In one embodiment, Bust support scrim 24 and/or second support scrim 16 are comprised of carded non-woven fibrous materials such as melt bonded non-woven material or Elise bonded carded non-woven, materials. The use of carded non-woven fibrous materials provide a cost advantage over the use of other non-woven and woven fibrous materials. Advantageously, multilayer filter media 34 has sufficient structure to be self supporting.
Multilayer filter media 34 may have a barley stiffness of at least S00 mg, 10241 First support scrim 24 and/or second support scrim 16 may have single component fibers, bicomponent fibers, or a mixture of both single component fibers and bicomponart fibers. In a preferred esnbod sent, first support scrim 24 and/or second support scrim 16 have bicomponeot fibers in a range of 30% to 100% with the remainder being single coupovent fibers. The bioomponemt fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. First support scam 24 and/or second support scrim 16 may be multilaye ed with a first and second layer where the first layer is bonded to porous CPTFE film 10 and the second layer is bonded to PAR 12127 = MOAT V1212011 rna si *M psi .tn Oaya~eh Tea114= svlee'ooem = ens see eso 700 442084 = eresY-11011 aaRagseN
tiastie image'-spates 10013/027 WO 3005/134117 PC FIVS2000#OS9016 the first layer. In one embodiment of a multileyered scrim, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer has bioomponent fibers with a polyester and a oo-polyester. In the process of bonding first support scrim 24 and second support swim 16 to porous ePTFE
film 10 as described above, at least a portion of the fibers in each scum layer are partially melted or softened to an extent which will provide the desired bond to film 10.
(0251 Typically, porous ePTFE film 10 has much smaller pores or void spaces than either support scrim 24 or second support series 16. Thus, it is the size of the pores in porous ePTFE film 10 which typically defines the efficiency of multilayer filter media 34, wherein the efficiency is the percentage of particles over a given size that are filtered out of a gas stream passed thetethrough However, in the instances wherein filter media 34 has a lower efficiency (<-- HEPA), the scam may define the efficiency of filter media 34. The size of the pores in porous ePTFE film 10 is proportional to the extent of expansion or stretching of porous ePTFE film 10. Typically, porous ePTFE film 10 is sequentially stretched, longitudinally then latitudinally, to an extent as to provide a desired efficiency of filter media 34. However, porous ePTFE film 10 may be expanded to an extant wherein the pore size therein is larger than the pore size of either support scrim 24. Filter media 34 may have an efficiency of at most 99.97% at 0.3p (< HEPA), or of at least 99.97% at 0.3g (" HEPA), greater than about 40% and less than IfEPA, or in a range of 40% to 99.999995% (ULPA) at a most penetrating particle size. Filter media 34 may have efficiency between. about 70% and 90%, advaotageoualy approxim lely 80%. Typically, filter media 34 has permeability in a range of 2 to 400 cf ntsq ft as measured with an air permeability measuring instrument, such as a Frazier, Te xtest, or other instrmment as known in the art.
1026) Figure lB shows schematic flow diagram 200 of an apparatus for producing an expanded polytettatluorodhylene containing filter media 40.
Lower scrim supply ro1126 feeds a scrim material 24 onto guide roller 22 which guides scrim material 24 onto heated bonding roller 28. A porous ePTFE film or sheet 10 is fed between guide roller 14 and amp roller 12 and has a first and. second surface wherein the first surface of porous ePTFE film 10 PA a 13137' R C Y D A T 1112120117:301 AM FwtNn D g j W 1 iu' svkrrONas' OIM:0000' Cap:1700 60 Will DU ATION 5%vn4$):0000 r unssie ima~a o~asemr W021151124417 ICT,X717 becomes adjacent support scrim 24 on heated bonding roller 28. Optionally, sprayer 33 applies a powdered polymeric material such as polyethylene to an inner surface of first scrim material 24, or alternatively to lower surf ce of porous cPTFE film 10. For a portion of a revolution of heated bonding roller 28, support scrim 24 comes into contact with hated bonding roller 28 and the first surface of porous ePTFE film 10, wherein at least a portion of the fibers in support scrim 24 are partially melted or softened to an extent to provide a bond to porous ePTFE film 10. Shortly after exit of bonded support scrim 24 and porous ePTFE film 10 from heated bonding roller 28, the composite passes by cooling jet30. Typically, cooling air jet 30 supplies cool air or other cooling fluid to cool the composite of support scrim 24 and porous ePTFE film 10 to a point where the softened or melted portions of support scrim 24 are hardened forming multilayer filter media 40 having porous ePTFE film 10 bonded to support scrim 24. Guide roller 32 is positioned so that media 40 is deflected in such a way upon exit from roller 28 that it maintains a desired lmg& of contact with the circumference of heated huller 28 to bonding properly bond support scrim 24 and porous ePTFE film 10 to form multilayer filter media 40, and also serves to guide multtilayer filter media 40 to a subsequent pleating zone.
[0271 Advantageously, support scrim 24 is comprised of carded non-woven fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Filter media 40 may have sufficient structure to be self supporting and advantageously bra a Gurley stifl'neas of at least 500 mg. Support scrim 24 may have single component fibers, bioomponent fibers, or a mixture of both single component fibers and bicomponent fibers. In a prefaced embodiment, support scrim 24 has bicomponent fibers in a range of 30% to 100% with the remainder being single component fibers. In a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or oopolyeater. Support scrim 24 may be multilayered with a first and second layer where the first layer is bonded to porous OPTFE film 10 and the second layer is bonded to the first layer. In one embodiment of a multilayered scum, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer PAeha 14 7 = RCVD AT 511 212 0 1 1 T:3210T AM ¾..*.m DIyaaat Ti1Nt' sva:Reooesf0' Dt1a:5000"Can:1700 a 5074.0( ATlON tin ss):0540 i~asaie iasge bpseei~s 0015/027 WO x01 /134117 PCT/US211W0S9NS
has bicomponent fibers with a polyester and a co-polyester. Filter media 40 may have an efficiency of at most 99.97% at 0.3p (<- HEPA), at least 99.97%
at 0.3ir (> HEPA), greater than about 40% and loss than HEPA, or in a range of 40% to 99.999995% at a most penetrating particle size. Typically, filter media 40 has a permeability in a range of 2 to 400 cfin/aq lt. Advantageously, fitters media 40 has sufficient structure to be self supporting with a Gurley stiffness of at least 500 mg.
! [028] Figure 1C shows schematic flow diagram 300 producing an expended polytetrafluoroelhylene containing filter media 50. Upper sorim supply roll 20 feeds a scrim material 16 onto guide roller 18 which guides acrim material 16 between guide roller 14 and nip roller 12. A porous ePTFE
film or sheet 10 is fed between guide roller 14 and nip roller 12 and has a first and second surface wherein the second surface becomes adjacent support scrim 16 at guide roller 14. Optionally, sprayer 35 applies a powdered polymeric material such as polyethylene to the second surface of porous ePTFE film 10, or alternatively to the surface of scorn material 16 that contacts pomve ePTPE
flat 10. Both ncport scrim 16 and porous eP TFE film 10 are fed adjacently onto heated bonding roller 28 wherein the Bast surface of porous ePTFE film becomes adjacent hated bonding roller 28. For a portion of a revolution of boated bonding roller 28, the first surface of porous eFTFE film 10 is adjacent heated bonding roller 28 and support swim 16 is adjacent the second surface of porous ePTPE film 10 wherein at least a portion of the, fibers in support scrim 16 are partially melted or softened to an extent to provide a bond to porous ePTFE Min 10. Upon separation of porous ePTFE film 10 and support scrim 16.firom heated bonding roller 28 is ooohng jet 30. Typically, cooling jet 30 supplies cool air or other cooling fluid cooling porous ePTFE film 10 and support scrim 16 to a point when the softened or partially milted portions of support scrims 16 are hardened forming filter media 50 having porous ePTFE
film 10 and support scrim 16. Guide roller 32 is positioned about heated bonding roller 28 to provide a desired contacting circumference of boated bonding roller 28 with porous eYTFE film 10 and support elm 16 and to guide filter media 50 to a pleating zone.
=
PAGE 1527' MOAT ev191AO11 T:32.T AM pMO m DwyWTW4 a roosssu' DMa"MOs' cm1706 us sin' D{MTIOM ern ss) Mirr ~ast.e renege Bylte. J1016/027 [0291 Advantageously, support scrim 16 is comprised of carded now-woven fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Advantageously, filter media 50 has sufficient structure to be self supporting and more advantageously has a Curley stifs of at least 500 rag. Support scrim 16 may have single component fibers, bieomponeut fibers, or a mixture of both single component fibers and bicomponent fibers. In a preferred embodiment, support scrim 16 has bicomponent fibers in a range of 30% to 100% with the remainder being single component fibers. In a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. Support scrim 16 is optionally multilayered with a first and second layer where the first layer is bonded to porous ePTFE film 10 and the second layer is bonded to the first layer. In one en*odnoraut of a multilaye ed scrim, the first layer has bicomponent fibers with a polyester and a polyethylene and the second layer bas bicomponent fibers with a polyester and a co-polyester. Filter media 50 may have an efficiency of at most 99.97% at 0.3 (<' HEPA), at least 99.97%
at 0.3 L (x HEPA), greater Wan about 4006 and lees than HEPA, or in a range of 40% to 99.999995% (ULPA) at a most penetrating particle size. Typically,' filter media 50 has a permeability in a range of 2 to 400 afm/sq ft.
[0361 Figure 2A shows a sclwmatic flow diagram of process 400 arranged to form pleats in the expanded polytetrafluoroethylene containing fitter media 410 produced by the processes of PIQs. IM C or the like. This method includes the steps of heeding a longitudinally extending continuous flat skeet of porous filter media 410 from a supply zone or directly from a process of making such as disclosed in FiGs. IA-1C. Porous filter media 410 can be any one of several materials as above described, inch rdiwg CPTPE with a single scrim, single or multi layyer~eed, or a scrim material joined to a first and second surthce when the second scrim may be single or multilayercd. Filter media 410 is fed between a per of cooperating gear pleating wheels 420 and 430 each having a star shaped periphery. The periphery of gears 420 and 430 cooperate to respectively engage filter media 410 to form valleys and crests in filter media 410 to produce pleated filter media 440. Optionally, filter media 440 can be heated to aid in the formation of fixed valleys and crests do6niag PA0a 1W27 - RCVD AT 0M2r30117:32:07 AM $uarn W 4M TUnar- avR:FOOos3I =
Craa:000 = Cap:170b 40 0514 - DURAUON 41nrss):0540 usatte xaage ayste>r Q0017/027 WO 2505(124417 PCTIUS20NnS9ISS
pleats in pleated filter media 440. Heating can be accomplished by heating upper gear 420 and lower gear 430, with heat plates 414, or both. Filter media 440 than is fed on an appropriate endless belt conveyor 450 moving at a preselected speed, a sower speed than the speed at which filter media 410 is fed to between gears 420 and 430. Filter media 440 conveyed thereto is caused to fold into a plurality of pleats, providing the aforementioned crests and valleys.
[031) Figure 2B shows a schematic flow diagram of process 500 arranged to form pleats in the expanded poly tetrafluomethylene containing filter media 510 produced by any one of the processes of FKIS. WIC or the like. This method includes the stela of feeding a longitudinally extending contimroas flat sheet of porous filter media 510 from a supply zone or directly from a process of making such as disclosed in FIGs. lA-IC. Porous fitter media 510 can have ePTFE with a single scrim, single or multi layered, or a scrim material joined to a first and second surface where the second scrim maybe single or mahilayered. Filter media 510 is fed between a pair of cooperating scouring wheels 520 and 530, each having a periphery with at least one "V" shaped indentation and at least one "V" shaped projection. The at least one indentation in upper soonag wheel 520 cooperates with the at least one projection in lower scoring wheel 530 and the at least one projection in upper scoring wheel 520 cooperates with the at least one indentation in lower scoring wheel 530 for each rotation of scoring wheels 520 and 530. Optionally, filter media 540 can be heated to aid in the formation of transversely extending score lines in filter media 510. Heating can be accomplished by heating upper scoring wheel 520 and lower scoring wheel 530, with beat plates 514, or both.
Filter media 540 then is fed on an appropriate endless belt conveyor 550 moving at a preselected speed, a slower speed than the speed at which filter media 510 is fed to between scoring wheels 520 and 530. Filter media 540 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys.
[0321 Figure 2C shows a schematic taw diagram of process 600 arranged to form pleats in the expanded polyte t atluoroe hyiene containing filler media 610 produced by any one of the processes of FIGs. IA-1C or the like. This PACE 17127' RCYD AT 611212011 7:52:67 AM AMMm DMV TI I$" NR:PD06621r "
01111:3101' cac:1 701 662 0074' D{IRATIDR anwn uu):0546 wesie image systems 0018/027 WO 2008/124417 PCT/US2NWI5N$5 method includes the steps of feeding a longitudinally extending continuous flat sheet of porous filter media 610 from a supply zone or directly from a process of making such as disclosed in FIGs. IA-IC. Porous filter media 610 can have ePTFE with a single scrim, single or multi layered, or a scrim material joined to a first and second surface where the second scrim may be single or multilayered. Filter media 610 is fed between a pair of cooperating scoring wheels 620 and 630, each having a periphery with at least one projection.
Advantageously, the at least one projection in upper scoring wheal 620 cooperates with a pliable or softened material in lower scoring wheel 630 and the at least one projection in lower scoring wheel 630 cooperates with a pliable or softened material in upper scoring wheel 620 for each rotation of scoring wheels 620 and 630. Optionally, filter media 640 can be heated to aid in the formation of transversely extending score lines in filter media 640. Heating can be accomplished by heating upper scoring wheel 620 and lower scoring wheel 630, with heat plates 615, or both. Scored filter media 640 then is fed onto an appropriate endless belt conveyor 650 moving at a preselected speed, a slower speed than the speed at which filter media 610 is fed to between scoring wheels 620 and 630. Filter media 640 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys. It is to be understood that the geometry and configuration of the scores can be varied providing desirable pleat crests, valleys, and flanks.
[0331 Figure 2D shows a schematic flow diagram of process 700 arranged to form pleats in the expanded polytetrafluoroethylene containing filter media 710 produced by any one of the processes of FIGS. IA-IC or the like. This method includes the steps of feeding a longitudinally extending continuous flat sheet of porous filter media 710 from a supply zone or directly from a process of making such as disclosed in FIGS. IA-1C. Porous filter media 710 can have ePTFE with a single soling, single or multi layered, or a scrim material joined to a first and second surface where the second scrim maybe single or multilayered. Filter media 710 is fed between a pair of reciprocating knives 720 and 730, offset firm one another and transversely extending filter media 710. Suitably spaced knivea720 and 730 on opposed surfaces of filter media 710 serve to score and plat the flat sheet of filter media 710 in longitudinally PAGE 14127' RCVD AT 3117120117:22:07 AM B4utsm D.yugtd TMI4' avR:FOOI0 S' DNa:3000' C4a1:1 700 442 4074' DURATION $m , ):0440 Castle image System 0019/027 WO 2$0W124417 PCTNS200wsSloes spaced, transversely extending lines as media 710 is passed therethrough with longitudinally spaced score lines extending transversely between the opposed, spaced longitudinally extending edges of filter media 710 and with the longitudinally spaced score lines on one face of filter media 710 being offset from the score lines on the other or opposite face of filter media 710.
Advantageously, reciprocating knives 720 and 730 are heated to aid in the formation of transversely extending score lines in filter media 710, with heat plates 715, or both. Scored filter media 740 then is fed onto an appropriate endless belt conveyor 750 moving at a preselected speed, a slower speed than the speed at which filter media 710 is fed to between scoring knives 720 and 730. Filter media 740 conveyed thereto is caused to fold into a plurality of pleats, providing crests and valleys. It is to be understood that other types of apparatus can be employed in addition to those schematically disclosed herein to accomplish the novel steps herein described.
[034] Figure 3 shows filter media 800 produced by the processes of FIGs.
lB and IC or the like having a portion of the layers separated. Filter media 800 has a layer of porous ePTFE film 830 with a first scrim on a first surface.
The first scrim shown here is a multilayer scrim having layers 820 and 810.
Advantageously, first support scrim layers 810 and 820 are comprised of carded non-woven fibrous materials such as melt bonded carded non woven material or fuse bonded carded non-woven materials. Advantageously, filter media 800 has sufficient structure to be self supporting and has a Gsrley stiffness of at least 500 mg. Support scrim layers 810 and 820 may have single {
component fibers, bicomponent fibers, or a mixture of both single component fibers and bicomponent fibers. In one embodiment, scrim layers 810 and 820 have bicamponent fibers in a range of 30% to 100% with the zemahxUr being single component fibers. The bicomponent fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. In a preferred embodiment of the multilayered scxirn, layer 820 has bicomponent fibers with a polyester and a polyethylene and layer 810 has biccomponent fibers with a polyester and a copolyester.. Embodiments of filter media 800 having a higher efficiency, porous ePTFE film 830 has much smaller pores or PAse 10!11' MCVD AT WM21101I 1:32:07 AM RptMl DsyII * TMJNp = IVR:P00003Ji =
DNIi:3001 = Cen:1 706 N2 0074 = DUMTNhN erln4s):0640 Gastle image Systems BOZO/027 WO 20011124417 PCT/US200010590i5 void spaces than both scrim layers 820 and 810. Thus, the mutest of expansion or stretching of porous ePTFE film 830 is proportional to the efficiency of filter media NO. Embodiments of filter media 800 having a lower efficiency, scrim layers 820 and 810 may have a smaller pore size than ePTPE film 830 and define the efficiency of fitter media 34. Filter media 800 may have an efficiency of at most 99.97% at 0.311(c- HEPA), at least 99.97% at 0.3p (>
HEPA), greater than about 40% and less than HEPA, or in a cargo of 40% to 99.999995% at a most penetrating particle size, depending upon the desired application of filter media 800. Typically, filter media 800 has a permeability in a range of 2 to 400 cfmJsq ft 10351 Scrim layers 820 and 810 maybe either on an upstream or downstream surface of ePTFE layer 830. Having scrim layers 820 and 810 on an upstream surface provides for a thickness having void spaces which increases the holding capacity of filter media 800. Conversely, having scrim layers 820 and 810 on a downstream surface provides for the ability to clam filter media 800 by back pulsing or shaking. Back pulse cleaning is accomplished by temponwily reversing the flow of the fluid passing through filter media 800 to dislodge accumulated material from ePTFE layer 830.
Alternatively or additionally, fiber media 800 may be shaken to dislodge accumulated material from ePTFE layer 830. Shaking and/or back pulsing are effective cleaning methods when scrim )ayes 810. and 820 are on a downstream surface since the accumulated materials are relatively readily separated from ePTFE membrane 830 with ePTFE's low propensity to stick to or hold the accumulated materials. The enhanced pleanability allows filter 800 to be repeatedly cleaned.
[036) Figure 4 shows films media 900 produced by the process of FIG. IA
or the like having a portion of the layers separated. Filter media 900 has a layer of porous uuPTFE film 930 with a first scrim on a first surface and a second scrim on a second surf.ace. The first scrim shown here is a multrlayer scrim having layers 920 and 910. Advaubgeously, first support scrim layers 910 and 920 are comprised of carded non-woven fibrous materials sorb as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Second support scrim 940 is comprised of carded non-woven PAGE21i27"RCYDAT3I12120117:fI:O7AMPriamDWIWTWgoaVR ROQ
IO3N=DDa.3ON=C$D:17Ne20OF4.OIIOATIONp,m S$Asm Gaatle image systems Q021/027 WO 2008/124417 PC1/US2008/m9185 fibrous materials such as melt bonded carded non-woven material or fuse bonded carded non-woven materials. Even though second support scrim 940 is shown as having a single layer it is to be understood that second support scrim 940 may be multilayered and may be comprised of the same or different materials as the first support scrim having layers 920 and 910.
Advantageously, filter media 900 has sufficient structure to be self supporting and a Gurley stiffiress of at least 500 mg. Support scrim layers 910,920 and 940 may have single component fibers, bicomponent fibers, or a mixture of both single component fibers and bioomponent fibers. In one embodiment, scrim layers 910 and 920 have bicomponent fibers in a range of 30% to 100 /6 with the remainder being single component fibers. The bicomponent fibers have a high melting portion and a low melting portion, in a preferred aspect the high melting portion is polyester and the low melting portion is polyethylene or co-polyester. In a preferred embodiment of the multilaye ed scrim, layer 920 has bicomponent fibers with a polyester and a polyethylene and layer 910 has bicomponent fibers with a polyester and a co-polyester. In a preferred embodiment of the single layered scrim 940, layer 940 has bieomponent fibers with a polyester and a polyethylene. Filter media 900 may have an efficiency of at most 99.97% at 0.3g (< HEPA), at least 99.97% at 03p (> HEPA), greater than about 40% and less than HEPA, or in a range of 40% to 99.999995% at a most penetrating particle size, dependiaig upon the desired application of filter media 900. Typically, filter media 900 has a permeability in a range of2to400cfnfsgft.
(0371 While the present invention has been shown and described herein in what are considered to be the preferred embodiments thereof:, illustrating the results and advantages over the prior an obtained through the present invention, the invention is not limited to those specific embodiments. Thus, the forms of the invention shown and described herein are to be taken as illustrative only and other embodiments may be selected without departing from the scope of the present invention, as set forth in the claims appended hereto.
PAM 21W I RCW AT SM2120117:32:07 AM PYEwn D M Tti.q = $VR POOII = DNa:3100 =
Cn:1 100 002 0q4 = DU1117r0R õ :06x0 _ _._ ......_. ...._._. _..
Claims (49)
1. A fluid filter including an upstream and downstream surface and being capable of obtaining a desirable minimum efficiency at a low pressure drop having a media comprising:
a first relatively open pleatable support scrim comprised of a melt bonded non-woven material or a fuse bonded non-woven material with greater than 40% bi-component fibers, said first support scrim having a Gurley stiffness of at least 500mg;
a layer of expanded polytetrafluoroethylene having a first surface bonded to said first support scrim; and, said media being pleated and self-supporting.
a first relatively open pleatable support scrim comprised of a melt bonded non-woven material or a fuse bonded non-woven material with greater than 40% bi-component fibers, said first support scrim having a Gurley stiffness of at least 500mg;
a layer of expanded polytetrafluoroethylene having a first surface bonded to said first support scrim; and, said media being pleated and self-supporting.
2. The fluid filter of claim 1 having a second support scrim bonded to a second surface of said layer of expanded polytetrafluoroethylene.
3. The fluid filter of claim 2 wherein said second support scrim is comprised of a melt bonded non-woven material or a fuse bonded non-woven material.
4. The fluid filter of claim 1 wherein said fluid filter is self supporting.
5. The fluid filter of claim 4 wherein said first support scrim having bicomponent fibers in a range of 30% to 100% has a remainder of fibers being single component fibers.
6. The fluid filter of claim 5 wherein said bicomponent fibers of said first support scrim have high melting portion and low melting portion, said high melting portion being polyester and low melting portion being polyethylene or co-polyester.
7. The fluid filter of claim 6 wherein said bicomponent fibers of said first support scrim have a polyester and a co-polyester.
8. The fluid filter of claim 6 wherein said bicomponent fibers of said first support scrim have a polyester and a polyethylene.
9. The fluid filter of claim 1 wherein said first support scrim is multilayered having a first and second layer, said first layer being bonded to said expanded polytetrafluoroethylene, said second layer being bonded to said first layer,
10. The fluid filter of claim 9 wherein said first layer of said first support scrim has bicomponent fibers with a polyester and a polyethylene and said second layer of said first support scrim has bicomponent fibers with a polyester and a co-polyester.
11. The fluid filter of claim 2 wherein said second support scrim has bicomponent fibers.
12. The fluid filter of claim 11 wherein said bicomponent fibers of said second support scrim have high melting portion and low melting portion, said high melting portion being polyester and low melting portion being polyethylene or co-polyester.
13. The fluid filter of claim 12 wherein said bicomponent fibers of said second support scrim have a polyester and a co-polyester.
14. The fluid filter of claim 12 wherein said bicomponent fibers of said second support scrim have a polyester and a polyethylene.
15. The fluid filter of claim 2 wherein said second support scrim is multilayered having a first and second layer, said first layer being bonded to said expanded polytetrafluoroethylene, said second layer being bonded to said first layer.
16. The fluid filter of claim 15 wherein said first layer of said second support scrim has bicomponant fibers with a polyester and a polyethylene and said second layer of said second support scrim has bicomponent fibers with a polyester and a co-polyester.
17. The fluid filter of claim 1 wherein said media has a Gurley stiffness of at least 500 mg.
18. The fluid filter of claim 1 wherein said media has an efficiency of at most 99.97% at 0.3µ.
19. The fluid filter of claim 1 wherein said media has an efficiency of at least 99.97% at 0.3µ.
20. The fluid filter of claim 1 wherein said media has an efficiency in a range of 40% to 99.999995% at a most penetrating particle size.
21. The fluid filter of claim 1 wherein said media has a permeability in a range of 2 to 400 cfm/sq ft.
22. The fluid filter of claim 1 wherein said first surface is said upstream surface.
23. The fluid filter of claim 1 wherein said first surface is said downstream surface.
24. The fluid filter of claim 1 wherein said first support scrim and said layer of expanded polytetrafluoroethylene have a polymeric material therebetween providing bonding between said first support scrim and said expanded polytetrafluoromethylene.
25. The fluid filter of claim 2 wherein said media has a Gurley stiffness of at least 500 mg.
26. The fluid filter of claim 2 wherein said media has an efficiency of at most 99.97% at 0.3µ.
27. The fluid filter of claim 2 wherein said media has an efficiency of at least 99.97% at 0.3µ.
28. The fluid filter of claim 2 wherein said media has an efficiency in a range of 40% to 99.999995% at a most penetrating particle size.
29. The fluid filter of claim 2 wherein said media has a permeability in a range of 2 to 400 cfm/sq ft.
30. The fluid filter of claim 2 wherein said first surface is said upstream surface.
31. The fluid filter of claim 2 wherein said first surface is said downstream surface.
32. The fluid filter of claim 2 wherein said second support scrim and said layer of expanded polytetrafluoromethylene have a polymeric material therebetween providing bonding between said second support scrim and said expanded polytetrafluoroethylene.
33. A fluid filter having a media comprising:
a pleatable first support scrim having a melt bonded non-woven material or a fine bonded non-woven material said first support scrim having a Gurley stiffness of at least 500 mg;
a layer of expanded polytetrafluoroethylene having a first surface bonded to said first support scrim; and, said fluid filter media being pleated, self-supporting and with and having an efficiency greater than about 40% and less than 99.97% efficient at 0.3 micron.
a pleatable first support scrim having a melt bonded non-woven material or a fine bonded non-woven material said first support scrim having a Gurley stiffness of at least 500 mg;
a layer of expanded polytetrafluoroethylene having a first surface bonded to said first support scrim; and, said fluid filter media being pleated, self-supporting and with and having an efficiency greater than about 40% and less than 99.97% efficient at 0.3 micron.
34. The fluid filter of claim 33 wherein said media has an efficiency is about 80%.
35. The fluid filter of claim 33 wherein said multi-layer first support scrim has a fat layer bonded to said first surface of said expanded polytetrafluoroethylene, said first layer of said first support scrim having at least 30% bicomponent fibers.
36. The fluid filter of claim 35 wherein said bicomponent fibers of said first layer of said first support scrim have a polyester and a low melting portion selected from the group consisting of co-polyester and polyethylene.
37. The fluid filter of claim 35 wherein said bicomponent fibers of said first layer of said first support scrim have a polyester and a polyethylene, said multi-layer first support scrim having a second layer bonded to said first layer, said second layer having at least 30%
bicomponent fibers with a polyester and a co-polyester.
bicomponent fibers with a polyester and a co-polyester.
38. The fluid filter of claim 33 having a second support scrim bonded to a second surface of said expanded polytetrafluoroethylene, said second support having at least 30%
bicomponent fibers.
bicomponent fibers.
39. The fluid filter of claim 38 wherein said bicomponent fibers of said second support scrim have a polyester and a low melting portion selected from the group consisting of co-polyester and polyethylene.
40. The fluid filter of claim 39 wherein said second support scrim has a first and second layer, said first layer of said second support scrim being bonded to said expanded polytetrafluoroethylene and having at least 30% bicomponent fibers with a polyester and a polyethylene, said second layer of said support scrim having at least 30%
bicomponent fibers with a polyester and a co-polyester.
bicomponent fibers with a polyester and a co-polyester.
41. A method of making a fluid filter media comprising:
feeding at least one support scrim to a heat roll, wherein said at least one support scrim is a melt bonded non-woven material or a fine bonded non-woven material;
feeding expended polytetrafluoroethylene to said heat roll wherein said at least one support scrim contacts said expanded polytetrafluoroethylene;
bonding said expanded polytetrafluoroethylene to said at least one support scrim forming a layered filter media;
passing said layered filter media through a cooling jet so as to from a hardened multilayered filter media; and pleating said multilayered media.
feeding at least one support scrim to a heat roll, wherein said at least one support scrim is a melt bonded non-woven material or a fine bonded non-woven material;
feeding expended polytetrafluoroethylene to said heat roll wherein said at least one support scrim contacts said expanded polytetrafluoroethylene;
bonding said expanded polytetrafluoroethylene to said at least one support scrim forming a layered filter media;
passing said layered filter media through a cooling jet so as to from a hardened multilayered filter media; and pleating said multilayered media.
42. The method of making a fluid filter media of claim 41 wherein said pleating step is accomplished by feeding said multilayered media between two cooperating gear wheels.
43. The method of making a fluid filter media of claim 41 wherein said pleating step comprises feeding said multilayered media between two cooperating scoring wheels.
44. The method of making a fluid filter media of claim 41 wherein said pleating step comprises conveying said multilayered media from cooperating gear wheels or scoring wheels to an endless belt having a speed less than the speed with which said multilayered filter media enters said cooperating gear wheels or scoring wheels.
45. A fluid filter media comprising at least one pleatable scrim layer with a Gurley stiffness of at least 500 mg bonded to an ePTFE layer, said filter media having an efficiency between about 70% and 9%, said at least one scrim layer having melt bonded non-woven or fuse bonded non-woven bicomponent fibers.
46. The fluid filter media of claim 45 wherein said at least one scrim layer has at least 30%
bicomponent fibers.
bicomponent fibers.
47. The fluid filter media of claim 45 wherein said bicomponent fibers of said at least one scrim layer have a polyester and a low melting portion selected from the group consisting of co-polyester and polyethylene.
48. The fluid filter of Claim 1 wherein said first support scrim is carded.
49. The fluid filter of Claim 33 wherein said first support scrim is carded.
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| US11/696,773 US7837756B2 (en) | 2007-04-05 | 2007-04-05 | Filter with ePTFE and method of forming |
| US11/696,773 | 2007-04-05 | ||
| PCT/US2008/059085 WO2008124417A2 (en) | 2007-04-05 | 2008-04-02 | Filter with eptfe and method of forming |
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| CA2682984A1 CA2682984A1 (en) | 2009-10-05 |
| CA2682984C true CA2682984C (en) | 2012-06-26 |
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| CA2682984A Active CA2682984C (en) | 2007-04-05 | 2008-04-02 | Filter with eptfe and method of forming |
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| EP (1) | EP2142276B1 (en) |
| CA (1) | CA2682984C (en) |
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| TW (1) | TWI367124B (en) |
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| US8257459B2 (en) * | 2007-02-28 | 2012-09-04 | Hollingsworth & Vose Company | Waved filter media and elements |
| US20090053103A1 (en) * | 2007-08-20 | 2009-02-26 | William Patrick Mortimer | Non-linting sterilization packaging material |
| US8673040B2 (en) | 2008-06-13 | 2014-03-18 | Donaldson Company, Inc. | Filter construction for use with air in-take for gas turbine and methods |
| US8262780B2 (en) * | 2009-07-22 | 2012-09-11 | Bha Group, Inc | High performance gas turbine inlet filter (HEPA) using membrane media |
| US8282713B2 (en) * | 2009-12-16 | 2012-10-09 | Bha Group, Inc. | PTFE pleated filter element |
| JP5012990B2 (en) * | 2010-06-17 | 2012-08-29 | ダイキン工業株式会社 | Filter medium provided with porous membrane, manufacturing method thereof, filter pack, and filter unit |
| JP5917538B2 (en) * | 2010-11-08 | 2016-05-18 | エーエーエフ−マックウェイ インコーポレイテッド ディー／ビー／エー エーエーエフ インターナショナル | Aseptic pharmaceutical ePTFE filter and method of use |
| US9266068B2 (en) | 2010-11-08 | 2016-02-23 | American Air Filter Company, Inc. | Aerosol generator for EPTFE filter testing and method of use |
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| TWI367124B (en) | 2012-07-01 |
| US20110062077A1 (en) | 2011-03-17 |
| WO2008124417A3 (en) | 2009-04-23 |
| EP2142276B1 (en) | 2014-06-11 |
| WO2008124417A2 (en) | 2008-10-16 |
| CA2682984A1 (en) | 2009-10-05 |
| US20080245041A1 (en) | 2008-10-09 |
| TW200906471A (en) | 2009-02-16 |
| US20110232835A1 (en) | 2011-09-29 |
| ES2497499T3 (en) | 2014-09-23 |
| US7837756B2 (en) | 2010-11-23 |
| US7959705B2 (en) | 2011-06-14 |
| EP2142276A2 (en) | 2010-01-13 |
| US8152889B2 (en) | 2012-04-10 |
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