US Patent 7507378 Collection assembly

A plurality of container assemblies are provided. Each container assembly has substantially identical external dimensions. However, the internal volumes of certain container assemblies differ from the internal volumes of other container assemblies. The container assemblies are configured in accordance with the required volume of material to be collected or maintained in the respective container assemblies and to enable uniform head spaces despite the different volumes of materials in the respective container assemblies. Each container assembly may have an inner container and an outer container. The inner and outer containers may be assembled together or formed integrally by molding.