| 摘要 |
The invention provides a one-way pressure relief valve (310, 410) for attachment over a vent on an exterior surface of a closed package (11) containing a gas-producing product, the pressure relief valve (310, 410) having a particulate filter (316) and a flexible seal (318), characterized by a filter layer (316) of a strip-type material having a periphery (320) and first and second sides (322, 324) defining a body (326) therebetween, the filter layer (316) having a filter element (328) in the strip-type material providing passage of gas through the body (326) and obstruction of particulate matter; adhesive (20) on the filter layer second side (324) to adhere the pressure relief valve (310, 410) to the exterior surface of the closed package (11); and the flexible seal (318) joined selectively to the filter layer first side (322) to form a gas flow path (21) between the flexible seal (318) and the filter layer first side (322) along an unjoined region of the flexible seal (318) and filter layer (316) from the filter element (328) to the filter layer periphery (320), the flexible seal (318) having a first position in which the unjoined region seals the filter element (328) to obstruct gas flow through the body and a further position in which the unjoined region is spaced at least partially from the filter layer first side (322) and the filter element (328) by gas pressure exerted through the filter element (328) to permit one-way gas outflow through the gas flow path (21), whereby the pressure relief valve (310, 410) enables one-way pressurized gas out-flow from an interior of the closed package (11) through the filter element (328) and the gas flow path (21) while preventing particulate matter from interfering with sealing of the filter element (328) once gas pressure inside the package (11) is decreased. |
