Diaphragm comprising gamma stable composite elastomeric and thermoplastic material

Abstract

A diaphragm for a diaphragm valve includes a flange and a bellows. The flange including a flange outer surface, a flange inner surface, a flange outer edge, and a flange inner edge. The bellows being disposed within the flange inner edge. The diaphragm being formed of a core elastomeric material and at least one layer of a microporous thermoplastic material comprising a plurality of micropores. The microporous thermoplastic material being attached to at least a portion of an elastomeric material outer surface. A combined thickness of all layers of the microporous thermoplastic material being in a first range of between 0.5 µm and 12 µm. A volume ratio of core elastomeric material to microporous thermoplastic material being in a second range of between 1:1 and 100:1.

Description

DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIALCROSS REFERENCES AND PRIORITIES

[0001] This Application claims priority from International Application No. PCT / US2023 / 080277 filed on 17 November 2023, the teachings of which are incorporated by reference herein in their entirety.BACKGROUND

[0002] Diaphragm valves utilize a flexible diaphragm inside of a valve body in combination with a seat to open and close the path of a fluid through opposing ports. Traditionally, the diaphragms in a diaphragm valve have been constructed of elastomeric or elastomers with PTFE / thermoplastic materials.

[0003] In operation, the diaphragms are subjected to repeated flexing, steam and aggressive chemicals. Upon repeated flexure, and or the exposure to steam or harsh chemicals the silicone, EPDM or FKM elastomeric material may develop cracks in the side wall thereof and may rupture catastrophically.

[0004] In addition, PTFE diaphragms have proven difficult to sterilize for reuse. In many medical, chemical, and biological applications, it is desirable to utilize the same PTFE articles such as diaphragms for multiple manufacturing runs, or the like. To avoid contamination or bacteria growth from manufacturing run to manufacturing run, the elastomers and / or PTFE diaphragm must be sterilized prior to reuse. Typical sterilization methods such as steam or gamma radiation are known to degrade the PTFE material of the diaphragm thereby increasing the likelihood of catastrophic failure during subsequent uses.

[0005] The need exists, therefore, for an improved elastomer diaphragm for a diaphragm valve which is resistant to cracking over time and repeated flexure, and is stable during sterilization with gamma radiation or steam.SUMMARY

[0006] Described herein is a diaphragm for a diaphragm valve. The diaphragm includes a flange and a bellows. The flange having a flange outer surface, a flange inner surface, a flange outer edge, and a flange inner edge. The bellows disposed within the flange inner edge. The diaphragm is formed of a core elastomeric material and at least one layer of a microporous thermoplastic material comprising a plurality of micropores. The microporous thermoplastic material being attached to at least a portion of an elastomeric material outer surface. A combined thickness of all layers of the microporous thermoplastic material is in a first range of between 0.5 pm andDIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL12 pm. A volume ratio of core elastomeric material to microporous thermoplastic material is in a second range of between 1 : 1 and 100: 1.

[0007] In some embodiments, the core elastomeric material may be selected from the group consisting of platinum silicone, fluorinated silicone, ethylene propylene diene monomer rubber (EPDM), and fluorocarbon-based fluoroelastomers.

[0008] In certain embodiments, the microporous thermoplastic material may be selected from the group consisting of polytetrafluoroethylene, polypropylene, polyether ether ketone, polyurethane, polyethylene, and polyamide.

[0009] In some embodiments, the microporous thermoplastic material may comprise a plurality of micropores having an average pore size in a range of between 0.1 pm and 15 pm.

[0010] In certain embodiments, a portion of the core elastomeric material may extend into at least a portion of the micropores.

[0011] In some embodiments, the bellows may include a hole passing through a bellows central axis. In other embodiments, the bellows may include a stud attached to and extending from a bellows outer surface at a bellows central axis.

[0012] In certain embodiments, the flange may include a plurality of flange holes. When present, each flange hole may pass from the flange outer surface through the flange inner surface.

[0013] Also described herein is a diaphragm valve. The diaphragm valve may include a valve body, a diaphragm, and a bonnet assembly. The valve body having a valve inlet, a valve outlet, and a port connected to a fluid passageway between the valve inlet and the valve outlet. The diaphragm having a flange and a bellows. The flange having a flange outer surface, a flange inner surface, a flange outer edge, and a flange inner edge with the bellows being disposed within the flange inner edge. The flange inner surface being disposed against a port top surface. The bonnet assembly having a bonnet housing disposed against the flange outer surface, a compressor, and an actuator mechanically connected to the compressor.

[0014] The diaphragm in the diaphragm valve is formed of a core elastomeric material and at least one layer of a microporous thermoplastic material comprising a plurality of micropores. The microporous thermoplastic material being attached to at least a portion of an elastomeric material outer surface. A combined thickness of all layers of the microporous thermoplastic material is in a first range of betweenDIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL0.5 pm and 12 pm. A volume ratio of core elastomeric material to microporous thermoplastic material is in a second range of between 1 :1 and 100:1.

[0015] In some embodiments of the diaphragm valve, the core elastomeric material may be selected from the group consisting of platinum silicone, fluorinated silicone, ethylene propylene diene monomer rubber (EPDM), and fluorocarbon-based fluoroelastomers.

[0016] In certain embodiments of the diaphragm valve, the microporous thermoplastic material may be selected from the group consisting of polytetrafluoroethylene, polypropylene, polyether ether ketone, polyurethane, polyethylene, and polyamide.

[0017] In some embodiments of the diaphragm valve, the microporous thermoplastic material may comprise a plurality of micropores having an average pore size in a range of between 0.1 pm and 15 pm.

[0018] In certain embodiments of the diaphragm valve, a portion of the core elastomeric material may extend into at least a portion of the micropores.

[0019] In some embodiments of the diaphragm valve, the bellows may include a hole passing through a bellows central axis. In other embodiments, the bellows may include a stud attached to and extending from a bellows outer surface at a bellows central axis.

[0020] In certain embodiments of the diaphragm valve, the flange may include a plurality of flange holes. When present, each flange hole may pass from the flange outer surface through the flange inner surface.

[0021] In some embodiments of the diaphragm valve, the fluid passageway may include a weir.

[0022] In certain embodiments of the diaphragm valve, the actuator may be selected from the group consisting of a knob and screw, a hydraulic actuator, a pneumatic actuator, an electric actuator, a piezoelectric actuator, and an electromagnetic actuator.BRIEF DESCRIPTION OF FIGURES

[0023] FIG. l is a perspective view of a diaphragm for a diaphragm valve.

[0024] FIG. 2 is a side view of a diaphragm for a diaphragm valve.

[0025] FIG. 3 is a side view of layers of a diaphragm for a diaphragm valve.

[0026] FIG. 4 is a perspective view of an embodiment of a diaphragm for a diaphragm valve.DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL

[0027] FIG. 5 is a perspective view of an embodiment of a diaphragm for a diaphragm valve.

[0028] FIG. 6 is an exploded perspective view of a diaphragm valve.

[0029] FIG. 7 is an assembled cross section view of a diaphragm valve.DETAILED DESCRIPTION

[0030] Disclosed herein is a diaphragm for a diaphragm valve. As described herein and in the claims, the following numbers refer to the following structures as noted in the Figures.

[0031] 10 refers to a diaphragm valve.

[0032] 100 refers to a diaphragm.

[0033] 110 refers to a flange.

[0034] lll refers to a flange outer surface.

[0035] 112 refers to a flange inner surface.

[0036] 113 refers to a flange outer edge.

[0037] 114 refers to a flange inner edge.

[0038] 115 refers to a flange hole.

[0039] 120 refers to a bellows.

[0040] 121 refers to a hole.

[0041] 122 refers to a stud.

[0042] 123 refers to a bellows outer surface.

[0043] 125 refers to a bellows central axis.

[0044] 200 refers to a core elastomeric material.

[0045] 210 refers to an elastomeric material outer surface.

[0046] 300 refers to a microporous thermoplastic material.

[0047] 400 refers to a valve body.

[0048] 410 refers to an valve inlet.

[0049] 420 refers to a valve outlet.

[0050] 430 refers to a port.

[0051] 432 refers to a port top surface.

[0052] 440 refers to a fluid passageway.

[0053] 442 refers to a weir.

[0054] 500 refers to a bonnet assembly.

[0055] 510 refers to a bonnet housing.

[0056] 520 refers to a compressor.DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL

[0057] 530 refers to an actuator.

[0058] FIG. 1 illustrates a perspective view of a diaphragm (100) for a diaphragm valve ((10) as shown in FIGS. 6 and 7) with FIG. 2 showing the diaphragm in side view. As shown in FIG. 1, the diaphragm includes a flange (110) and a bellows (120). The flange has a flange outer edge (113) defining a perimeter of the diaphragm, and a flange inner edge (114) at an interface where the bellows connects to the flange such that the bellows is disposed within the flange inner edge.

[0059] In some embodiments, such as shown in FIG. 1, the flange (110) may include a plurality of flange holes (115). When present, each flange hole will pass from the flange outer surface ((113) as shown in FIG. 2) through the flange inner surface ((114) as shown in FIG. 2). These flange holes - when present - serve as an attachment point for connecting the diaphragm to the diaphragm valve ((10) as shown in FIGS. 6 and 7). The diaphragm may be connected to the diaphragm valve by passing a fastener - such as a bolt, rivet, screw, or the like - through one or more of the flange holes and into a portion of the valve body ((400) as shown in FIGS. 6 and 7). While FIG. 1 shows flange holes located in the four corners of the flange, the invention is not so limited, and other flange holes may exist at any number of positions in the flange.

[0060] FIG 3 illustrates a side view of a side view of a diaphragm (100) showing the material components thereof. As shown in FIG. 3, the diaphragm is formed of a core elastomeric material (200) and at least one layer of a microporous thermoplastic material (300) comprising a plurality of micropores. The microporous thermoplastic material may be connected to the elastomeric material by coating the core elastomeric material with the microporous thermoplastic material. Exemplary coating processes include knife over roll coating, gravure coating, roll-to-roll coating, and ultrasonic spraying.

[0061] The number of layers of microporous thermoplastic material (300) may vary by application. In general, the diaphragm will include at least one layer of microporous thermoplastic material. However, embodiments will exist where the diaphragm includes at least two layers of microporous thermoplastic material, at least five layers of microporous thermoplastic material, at least ten layers of microporous thermoplastic material, or at least twenty-five layers of microporous thermoplastic material. Microporous, as used herein, refers to the average pore size of the thermoplastic material as referred to herein. Combined, all layers of theDIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL microporous thermoplastic material will have a thickness which may be in a range selected from the group consisting of between 0.5 pm and 12 pm, between 0.5 pm and 10 pm, between 0.5 pm and 7.5 pm, between 0.5 pm and 5.0 pm, between 1.0 pm and 12 pm, between 1.0 pm and 10 pm, between 1.0 pm and 7.5 pm, between 1.0 pm and 5.0 pm, between 2.0 pm and 12 pm, between 2.0 pm and 10 pm, between 2.0 pm and 7.5 pm, and between 2.0 pm and 7.5 pm.

[0062] When combined into the diaphragm (100), the core elastomeric material (200) and the microporous thermoplastic material (300) will have a volume ratio. The volume ratio of core elastomeric material to microporous thermoplastic material may be in a range of between 1 : 1 and 100: 1, between 1 : 1 and 75: 1, between 1 : 1 and 50: 1, between 1 : 1 and 25: 1, between 5: 1 and 100: 1, between 5: 1 and 75: 1, between 5: 1 and 50: 1, between 5: 1 and 25: 1, between 10: 1 and 100: 1, between 10: 1 and 75: 1, between 10: 1 and 50: 1, and between 10: 1 and 25: 1.

[0063] Any number of different elastomeric materials may be used for the core elastomeric material (200) of the diaphragm (100). Preferred examples of such elastomeric materials include platinum silicone, fluorinated silicone, ethylene propylene diene monomer rubber (EPDM), and fluorocarbon-based fluoroelastomers.

[0064] Any number of different microporous thermoplastic materials may be used. Preferred examples of such microporous thermoplastic materials include polytetrafluoroethylene (PTFE), polypropylene (PP), polyether ether ketone (PEEK), polyurethane, polyethylene (PE), and polyamide.

[0065] The plurality of micropores of the microporous thermoplastic material (300) will have an average pore size. Preferably, the average pore size will be in a range selected from the group consisting of between 0.1 pm and 15 pm, between 0.1 pm and 10 pm, between 0.1 pm and 7.5 pm, between 0.1 pm and 5.0 pm, between 1.0 pm and 15 pm, between 1.0 pm and 10 pm, between 1.0 pm and 7.5 pm, between 1.0 pm and 5.0 pm, between 2.0 pm and 15 pm, between 2.0 pm and 10 pm, between 2.0 pm and 7.5 pm, and between 2.0 pm and 5.0 pm. The thermoplastic material may be provided in a microporous form - such as a membrane of the material comprising micropores or as an open weave of thermoplastic material that is heat set to attach to the core elastomeric material forming micropores in the process. The microporous thermoplastic material may beDIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL attached to at least a portion of the core elastomeric material in a manner such that a portion of the elastomeric material extends into at least a portion of the micropores.

[0066] FIG. 4 and FIG. 5 illustrate different embodiments for attaching a bellows (120) of a diaphragm (100) to a diaphragm drive mechanism ((500) as shown in FIGS. 6 and 7). As shown in FIG. 4, one embodiment includes a hole (121) passing through a bellows central axis (125) through which a drive shaft of the diaphragm drive mechanism passes and attaches. Another embodiment, shown in FIG. 5, includes a stud (122) attached to and extending from a bellows outer surface (123) at the bellows central axis (125). In such embodiments, the drive shaft of the diaphragm drive mechanism may mechanically attach to the stud.

[0067] FIG. 6 illustrates an exploded perspective view of a diaphragm valve (10) within which the embodiments of a diaphragm (100) disclosed herein may be useful with FIG. 7 illustrating a cross-section view of an assembled diaphragm valve. As shown in FIG. 6, the diaphragm valve may include a valve body (400), a diaphragm, and a bonnet assembly (500).

[0068] The diaphragm (100) may be of any type disclosed herein. In general, the diaphragm may include a flange (110) and a bellows (120). The flange has a flange outer edge (113) defining a perimeter of the diaphragm, and a flange inner edge (114) at an interface where the bellows connects to the flange such that the bellows is disposed within the flange inner edge.

[0069] In some embodiments, such as shown in FIG. 6, the flange (110) may include a plurality of flange holes (115). When present, each flange hole will pass from the flange outer surface (113) through the flange inner surface (114). These flange holes - when present - serve as an attachment point for connecting the diaphragm to the valve body (400). The diaphragm (100) may be connected to the valve body by passing a fastener (which may or may not be molded in-place)- such as a bolt, rivet, screw, or the like - through one or more of the flange holes and into a portion of the valve body, in particular corresponding holes passing through a surface of a port (430) of the valve body. While FIG. 6 shows flange holes located in the four corners of the flange, the invention is not so limited, and other flange holes may exist at any number of positions in the flange.

[0070] As shown in FIG. 6 and FIG. 7, the valve body (400) may include a valve inlet (410), a valve outlet (420), a port (430), and a fluid passageway (440). The valve inlet referring to a fitting, hose barb, or other opening allowing fluid fromDIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL outside of the valve body to pass into the fluid passageway. The valve outlet referring to a fitting, hose barb, or other opening allowing fluid from the fluid passageway to exit the pump body.

[0071] As further shown in FIG. 6 and FIG. 7, the bonnet assembly (500) may include a bonnet housing (510), a compressor (520), and an actuator (530). The bonnet housing being disposed against the flange outer surface (111) with the flange inner surface disposed against a port top surface (432) such that the diaphragm is sandwiched between the bonnet housing and the port. The actuator passes through a hole in the bonnet housing and mechanically connects to the compressor, which itself is mechanically connected to the bellows (120).

[0072] In operation, the actuator (530) operates linearly on the compressor (520) which moves the bellows (120) from a retracted position as shown in FIG. 7 to an extended position. When in the extended (or a partially extended) position, the bellows blocks (or reduces) the flow of fluid through the fluid passageway (440). In some embodiments, the fluid passageway will include a weir (442) which - when present - assists in precision control of the amount of fluid which may flow through the fluid passageway.

[0073] The diaphragms disclosed herein comprised of a core elastomeric material and a microporous thermoplastic or PTFE material have been observed to achieve improved resistance to cracking over time and repeated flexure when compared to known silicone elastomer diaphragms. In addition, the diaphragms disclosed herein are gamma-stable. That is to say that the diaphragms disclosed herein can be sterilized using gamma radiation without degrading the core elastomeric material.

[0074] While the diaphragm has been described as having one or more exemplary designs, the diaphragm may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the diaphragm using its general principles.

Claims

DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIALCLAIMSWhat is claimed is:

1. A diaphragm (100) for a diaphragm valve (10), said diaphragm comprising: a flange (110) having a flange outer surface (111), a flange inner surface (112), a flange outer edge (113), and a flange inner edge (114); and a bellows (120) disposed within the flange inner edge; and wherein the diaphragm is formed of a core elastomeric material (200) and at least one layer of a microporous thermoplastic material (300) comprising a plurality of micropores, said microporous thermoplastic material being attached to at least a portion of an elastomeric material outer surface (210), wherein a combined thickness of all layers of the microporous thermoplastic material is in a first range of between 0.5 pm and 12 pm, and wherein a volume ratio of core elastomeric material to microporous thermoplastic material is in a second range of between 1 : 1 and 100: 1.

2. The diaphragm of claim 1, wherein the core elastomeric material is selected from the group consisting of platinum silicone, fluorinated silicone, ethylene propylene diene monomer rubber (EPDM), and fluorocarbon-based fluoroelastomers.

3. The diaphragm of any of claims 1 to 2, wherein the microporous thermoplastic material is selected from the group consisting of polytetrafluoroethylene, polypropylene, polyether ether ketone, polyurethane, polyethylene, and polyamide.

4. The diaphragm of any of claims 1 to 3, wherein the microporous thermoplastic material comprises a plurality of micropores having an average pore size in a range of between 0.1 pm and 15 pm.

5. The diaphragm of claim 4, wherein a portion of the core elastomeric material extends into at least a portion of the micropores.

6. The diaphragm of any of claims 1 to 5, wherein the bellows includes a hole(121) passing through a bellows central axis (125).

7. The diaphragm of any of claims 1 to 5, wherein the bellows includes a stud(122) attached to and extending from a bellows outer surface (123) at a bellows central axis (125).DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL8. The diaphragm of any of claims 1 to 7, wherein the flange includes a plurality of flange holes (115), each flange hole passing from the flange outer surface through the flange inner surface.

9. A diaphragm valve (10) comprising: a valve body (400) having a valve inlet ( 10), a valve outlet (420), and a port (430) connected to a fluid passageway (440) between the valve inlet and the valve outlet; a diaphragm (100) having a flange (110) and a bellows (120), said flange having a flange outer surface (111), a flange inner surface (112), a flange outer edge (113), and a flange inner edge (114), said bellows being disposed within the flange inner edge, and said flange inner surface being disposed against a port top surface (432); a bonnet assembly (500) having a bonnet housing (510) disposed against the flange outer surface, a compressor (520), and an actuator (530) mechanically connected to the compressor; and wherein the diaphragm is formed of a core elastomeric material (200) and at least one layer of a microporous thermoplastic material (300) comprising a plurality of micropores, said microporous thermoplastic material being attached to at least a portion of an elastomeric material outer surface (210), wherein a combined thickness of all layers of the microporous thermoplastic material is in a first range of between 0.5 pm and 12 pm, and wherein a volume ratio of core elastomeric material to microporous thermoplastic material is in a second range of between 1 : 1 and 100: 1.

10. The diaphragm valve of claim 9, wherein the core elastomeric material is selected from the group consisting of platinum silicone, fluorinated silicone, ethylene propylene diene monomer rubber (EPDM), and fluorocarbon-based fluoroelastomers.

11. The diaphragm valve of any of claims 9 to 10, wherein the microporous thermoplastic material is selected from the group consisting of polytetrafluoroethylene, polypropylene, polyether ether ketone, polyurethane, polyethylene, and polyamide.

12. The diaphragm valve of any of claims 9 to 11, wherein the microporous thermoplastic material comprises a plurality of micropores having an average pore size in a range of between 0.1 pm and 15 pm.DIAPHRAGM COMPRISING GAMMA STABLE COMPOSITE ELASTOMERIC AND THERMOPLASTIC MATERIAL13. The diaphragm valve of claim 12, wherein a portion of the core elastomeric material extends into at least a portion of the micropores.

14. The diaphragm valve of any of claims 9 to 13, wherein the bellows includes a hole (121) passing through a bellows central axis (125) to which the compressor is attached.

15. The diaphragm valve of any of claims 9 to 13, wherein the bellows includes a stud (122) attached to and extending from a bellows outer surface (123) at a bellows central axis (125) to which the compressor is attached.

16. The diaphragm valve of any of claims 9 to 15, wherein the flange includes a plurality of flange holes (115), each flange hole passing from the flange outer surface through the flange inner surface.

17. The diaphragm valve of any of claims 9 to 16, wherein the fluid passageway includes a weir (442).

18. The diaphragm valve of any of claims 9 to 17, wherein the actuator is selected from the group consisting of a knob and screw, a hydraulic actuator, a pneumatic actuator, an electric actuator, a piezoelectric actuator, and an electromagnetic actuator.

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