Abstract: A cap with a way-one valve solves two distinct problems in the field of packaging materials that emit gasses, providing both a means to prevent a package from deforming under pressure built up inside the package, and a means to reseal the package. The cap comprises an inner wall extending downwardly from an inner portion of the top wall to define a cavity. An insert valve is mounted within the cavity, forming a seal with the inside wall. The upper surface of the insert valve, inner wall, and the top wall define a chamber with a gas escape path. A septum is disposed within the chamber, the septum seated on the insert valve and sealing one or more apertures in the insert valve. The septum is capable of at least partially unseating in response to force exerted by increased gas pressure acting through the apertures.

Abstract: A cap with a way-one valve solves two distinct problems in the field of packaging materials that emit gasses, providing both a means to prevent a package from deforming under pressure built up inside the package, and a means to reseal the package. The cap comprises an inner wall extending downwardly from an inner portion of the top wall to define a cavity. An insert valve is mounted within the cavity, forming a seal with the inside wall. The upper surface of the insert valve, inner wall, and the top wall define a chamber with a gas escape path. A septum is disposed within the chamber, the septum seated on the insert valve and sealing one or more apertures in the insert valve. The septum is capable of at least partially unseating in response to force exerted by increased gas pressure acting through the apertures.