Testing container seals
AssigneeBenthos, Inc.
InventorWilliam H. Hulsman
Life of this patent
Estimating the term…
Abstract
Leak detector for use in detecting defective flange-shaped seals between lid and body portions of a package. A pressure chamber is provided for isolating the external edge of the seal and applying test pressure thereto. Containment of the pressure chamber includes sealing pressure applied mechanically to the flange-shaped package seal during testing, but this sealing pressure does not affect seal testing because it is appropriately limited by a self-compensating biasing of the mechanical seal. Also disclosed is a leak testing method that involves directing gas over a flexible lid at sufficiently high velocity to lift the lid at gross defects in a seal and inject gas through the gross defects. Also disclosed is a package design that employs channels to direct gas into a seal region.
Claims28
A method for detecting a leak in a defective seal of a package having an edge seal that is formed by a bond between overlapping edge portions of walls of said package, one said wall having a flexible portion that changes shape as the volume in said package changes, one said wall being a flexible lid of said package, said method comprising
- providing said package,
- applying a gas to exposed outer edges of said edge portions and along the outer surface of said lid at sufficiently high velocity to lift said lid at a gross leak in said seal and inject said gas through said gross leak into said container, and
- detecting deflection of said flexible portion in response to flow of gas through a leak in said edge seal between said overlapping edge portions.
Apparatus for detecting a leak in a defective seal of a package having an edge seal that is formed by a bond between overlapping edge portions of walls of said package, one said wall having a flexible portion that changes shape as the volume in said package changes, one said wall being a flexible lid of said package, said apparatus comprising
- means to apply a gas to exposed outer edges of said edge portions and along the outer surface of said lid at sufficiently high velocity to lift said lid at a gross leak in said seal and inject said gas through said gross leak into said container, and
- a deflection detector to detect deflection of said flexible portion in response to flow of gas through a leak in said edge seal between said overlapping edge portions.
A method for detecting a leak in a defective seal of a package having an edge seal that is formed by a bond between overlapping edge portions of walls of said package, one said wall having a flexible portion that changes shape as the volume in said package changes, said overlapping edge portions including bond portions and unbonded portions extending outward from said bond portions, said unbonded portions including elongated recesses in a said wall leading to said bond portions to provide channels between said overlapping edge portions leading to said bond portions, said method comprising
- providing said package,
- applying a first pressure to said channels and a different second pressure to said flexible portion, and .
- detecting deflection of said flexible potion in response to flow of gas through a leak in said edge seal between said overlapping edge portions.
A method for detecting a leak in a defective seal of a package having an edge seal that is formed by a bond between overlapping edge portions of walls of said package, one said wall having a flexible portion that changes shape as the volume in said package changes, said method comprising
- providing said package,
- applying a first pressure to exposed outer edges of said edge portions of said walls and a different second pressure to said flexible portion, and
- detecting deflection of said flexible portion in response to flow of gas through a leak in said edge seal between said overlapping edge portions,
- said applying including providing a first chamber that is partially defined by said exposed outer edges of said edge portions,
- said first chamber being partially defined by a seal member that seals against a said wall between said exposed outer edge portions and said flexible portion.
Apparatus for detecting a leak in a defective seal of a package having an edge seal that is formed by a bond between overlapping edge portions of walls of said package, one said wall having a flexible portion that changes shape as the volume in said package changes, said apparatus comprising
- means to apply a first pressure to exposed outer edges of said edge portions of said walls and a different second pressure to said flexible portion, and
- a deflection detector to detect deflection of said. flexible portion in response to flow of gas through a leak in said e seal between said overlapping edge portions,
- said means to apply including first chamber means defining a first chamber that is partially defined by said exposed outer edges of said edge portions,
- said first chamber means including a seal member that seals against a said wall between said exposed outer edge portions and said flexible portion.
Dependencies are inferred from the claim text.