Edge coated gaskets and method of making same
View Patent ↗An edge coated gasket includes a base sheet made of compressible gasket material and having opposed faces and an interior edge surrounding and defining an aperture. An edge coating of polymer or other material is disposed on and seals the interior edge of the base sheet and may project beyond the facial planes of the base sheet to define protruding rims extending around the aperture. Face coatings may also be applied to one or more of the faces extending in relatively narrow strips around the aperture of the base sheet. When clamped between flange surfaces, the edge coating engages, conforms to, and seals against the flange surfaces to provide a seal against both interfacial and intersticial migration of fluid past the gasket. At the same time, the inherently good compression failure resistance of the compressible gasket material of the base sheet is preserved. Thus, a gasket with enhanced sealability and compression failure resistance is provided. A unique method of making such an edge coated gasket is also disclosed.
1. A gasket comprising:
a base sheet of contiguous substantially porous gasket material having a predetermined thickness and two opposed substantially parallel faces lying in respective facial planes, said faces for contacting respective flange surfaces between which said gasket is to be clamped;
said base sheet being configured to define at least one aperture bounded by an interior edge of said base sheet;
an edge coating disposed on and extending around said interior edge of said base sheet, said edge coating being formulated of a compressible material that provides a seal when compressed between a pair of flange surfaces;
said edge coating having an interior surface facing said aperture and an exterior surface facing said interior edge of said base sheet and being inboard of said interior edge such that said edge coating does not overlap onto said parallel faces, said interior surface being convex in shape, and said exterior surface being generally convex in shape with a flattened central portion on said interior edge of said base sheet,
said interior surface and said exterior surface being coterminous at a first endpoint and a second endpoint, wherein said first endpoint and said second endpoint lie in respective planes spaced from the facial planes of said two opposed substantially parallel gasket faces to form a pair of rims protruding from said opposed substantially parallel gasket faces.
2. A gasket as claimed in claim 1 and wherein said edge coating is a polymeric coating.
3. A gasket as claimed in claim 2 and wherein said polymeric coating is selected from the group consisting essentially of:
acrylic, acrylonitrile, acrylonitrile butadiene rubber, fluoro polymers, hydrogenated acrylonitrile butadiene rubber, styrene butadiene polymer, fluoroelastomer polymer, acrylic-acrylonitrile polymers, carboxylated acrylonitrile polymer, carboxylated styrene butadiene polymer, polyvinylidene chloride, chloroprene rubber polymer, ethylene propylene rubber polymer, ethylene/vinyl acetate polymer, epoxy, fluorosilicones, polyurethane, and silicone rubber coatings and mixtures thereof.
4. A gasket as claimed in claim 1 and wherein said edge coating is a latex coating.
5. A gasket as claimed in claim 1 and wherein said edge coating is a powder fused coating.
6. A gasket as claimed in claim 1 and wherein said edge coating penetrates said interior edge a predetermined distance to form an increased density intrusion zone of said base sheet surrounding said aperture for enhancing clamping pressure within said intrusion zone.
7. A gasket as claimed in claim 6 and wherein said intrusion zone has a width that is at least twice the maximum thickness of said edge coating.
8. A gasket comprising:
a base sheet of contiguous substantially porous gasket material having a predetermined thickness and two opposed substantially parallel faces lying in respective facial planes, said faces for contacting respective flange surfaces between which said gasket is to be clamped;
said base sheet being configured to define at least one aperture bounded by an interior edge of said base sheet;
an edge coating disposed on and extending around said interior edge of said base sheet, said edge coating being formulated of a compressible material that provides a seal when compressed between a pair of flange surfaces;
said edge coating having an interior surface facing said aperture and an exterior surface facing said interior edge of said base sheet and being inboard of said interior edge such that said parallel faces are free from contact with said edge coating;
said edge coating having a cross-sectional area being generally biconvex in shape, the cross-sectional area being defined by a height and a width, the width being the thickness of said coating extending between said interior surface and said exterior surface, and the height being the thickness of said coating extending in a direction substantially perpendicular to said opposed substantially parallel gasket faces, the height being greater than the width and projecting beyond said facial planes, thereby defining a pair of opposed protruding rims of said edge coating.
9. A gasket as claimed in claim 8 and wherein said edge coating is selected from the group consisting of a polymeric coating, a latex coating, and a powder fused coating.
10. A gasket as claimed in claim 8 and wherein said edge coating is a polymeric coating selected from the group consisting essentially of:
acrylic, acrylonitrile, acrylonitrile butadiene rubber, fluoro polymers, hydrogenated acrylonitrile butadiene rubber, styrene butadiene polymer, fluoroelastomer polymer, acrylic-acrylonitrile polymers, carboxylated acrylonitrile polymer, carboxylated styrene butadiene polymer, polyvinylidene chloride, chloroprene rubber polymer, ethylene propylene rubber polymer, ethylene/vinyl acetate polymer, epoxy, fluorosilicones, polyurethane, and silicone rubber coatings and mixtures thereof.
11. A gasket as claimed in claim 8 and wherein said edge coating penetrates said interior edge a predetermined distance to form an increased density intrusion zone of said base sheet surrounding said aperture for enhancing clamping pressure within said intrusion zone.
12. A gasket as claimed in claim 11 and wherein said intrusion zone has a width that is at least twice the maximum thickness of said edge coating.
13. A gasket comprising:
a base sheet of contiguous substantially porous gasket material having a predetermined thickness and two opposed substantially parallel faces lying in respective facial planes, said faces for contacting respective flange surfaces between which said gasket is to be clamped;
said base sheet being configured to define at least one aperture bounded by an interior edge of said base sheet;
an edge coating disposed on and extending around said interior edge of said base sheet, said edge coating being formulated of a compressible material that provides a seal when compressed between a pair of flange surfaces, wherein said edge coating penetrates said interior edge a predetermined distance to form an increased density intrusion zone of said base sheet surrounding said aperture for enhancing clamping pressure within said intrusion zone, said intrusion zone having a width that is at least twice the maximum thickness of said edge coating;
said edge coating having a generally elliptical cross-sectional profile with a major axis substantially perpendicular to said faces and a minor axis substantially parallel to and intermediate said faces, said major axis being greater in length than the predetermined thickness of said base sheet.
14. A gasket as claimed in claim 13 and wherein said edge coating is selected from the group consisting of a polymeric coating, a latex coating, and a powder fused coating.
15. A gasket as claimed in claim 13 and wherein said edge coating is a polymeric coating selected from the group consisting essentially of:
acrylic, acrylonitrile, acrylonitrile butadiene rubber, fluoro polymers, hydrogenated acrylonitrile butadiene rubber, styrene butadiene polymer, fluoroelastomer polymer, acrylic-acrylonitrile polymers, carboxylated acrylonitrile polymer, carboxylated styrene butadiene polymer, polyvinylidene chloride, chioroprene rubber polymer, ethylene propylene rubber polymer, ethylene/vinyl acetate polymer, epoxy, fluorosilicones, polyurethane, and silicone rubber coatings and mixtures thereof.
16. A gasket comprising:
a base sheet of contiguous substantially porous gasket material having a predetermined thickness and two opposed substantially parallel faces lying in respective facial planes, said faces for contacting respective flange surfaces between which said gasket is to be clamped;
said base sheet being configured to define at least one aperture bounded by an interior edge of said base sheet;
an edge coating disposed on and extending around said interior edge of said base sheet, said edge coating being formulated of a compressible material that provides a seal when compressed between a pair of flange surfaces;
said edge coating having an interior surface facing said aperture and an exterior surface facing said interior edge of said base sheet and being inboard of said interior edge such that said parallel faces are free from contact with said edge coating;
said edge coating having a generally oblong cross-sectional profile with a somewhat flattened portion adjacent said interior edge of said base sheet, and a pair of opposed, generally arcuate portions projecting beyond said facial planes defining protruding rims of said edge coating.
17. A gasket as claimed in claim 16 and wherein said edge coating is selected from the group consisting of a polymeric coating, a latex coating, and a powder fused coating.
18. A gasket as claimed in claim 16 and wherein said edge coating is a polymeric coating selected from the group consisting essentially of:
acrylic, acrylonitrile, acrylonitrile butadiene rubber, fluoro polymers, hydrogenated acrylonitrile butadiene rubber, styrene butadiene polymer, fluoroelastomer polymer, acrylic-acrylonitrile polymers, carboxylated acrylonitrile polymer, carboxylated styrene butadiene polymer, polyvinylidene chloride, chioroprene rubber polymer, ethylene propylene rubber polymer, ethylene/vinyl acetate polymer, epoxy, fluorosilicones, polyurethane, and silicone rubber coatings and mixtures thereof.
19. A gasket as claimed in claim 16 and wherein said edge coating penetrates said interior edge a predetermined distance to form an increased density intrusion zone of said base sheet surrounding said aperture for enhancing clamping pressure within said intrusion zone.
20. A gasket as claimed in claim 16 and wherein said intrusion zone has a width that is at least twice the maximum thickness of said edge coating.