| Figure #1 illustrates the critical aspects of the three
seal design. The figure also depicts the position of the lid as it
approaches the container during closing. The hinged design positions the
lid at the appropriate angle to ensure proper closure. |

Figure #1 |
| The first seal is formed by the union of the lid valve
(Figure #2) with the inside surface of the container wall. The integrity
of this seal is obtained by forcing the top of the container into a
small space between the valve and the wall of the lid. The structural
interference encountered during closing and the shrinkage that occurs
during the curing stage create the airtight seal. |

Figure #2
|
| The second seal is formed by the union of the
top edge of the container wall (Figure #3) and the inside wall of the
lid. Similar to the first seal, it is a combination of structural
interference and shrinkage that guarantees the integrity of the seal.
This feature's primary function is to provide a leak proof seal that
prevents fluids from entering or exiting the container. |

Figure #3
|
| The third seal is formed by the union of the outer wall
of the container (Figure #4) and the undercut around the inside wall of
the lid. This seal provides the another layer of protection against
fluid ingress and egress and also determines the amount of internal air
pressure the container will withstand. The level of internal air
pressure is controlled by the ratio of surface contact to undercut. |

Figure #4
|