Abstract: An vented vial stopper for use in processing freeze-dried products is provided. The stopper includes a vent passageway that is covered with a waterproof and moisture vapor permeable membrane to allow the venting of moisture during the freeze-drying process. The membrane also extends to cover most or all of the exposed surface of the stopper to protect the stopper from chemical attack during processing.

Abstract: An improved filter unit suitable for use in a variety of clean air filtration applications is taught. The filter unit employs continuous microporous filtration membranes, such as expanded polytetrafluoroethylene, to deliver exceptional filtration efficiencies on the order of 99.99999% at 0.1 .mu.m with minimal pressure drop produced across the filter. Additionally, the filter unit of the present invention has the further advantage of avoiding many previous deficiencies in HEPA and ULPA filter units, such as filter contamination from shedding particles and/or out-gassing, and limitations on chemicals to which the filter can be exposed without deterioration. As a result, the present invention provides a cleaner and more durable filter that can be used to address growing contamination problems in many different industries, such as electronics and pharmaceuticals.

Abstract: An improved air diffusion panel, and method of construction and use, is provided which is particularly suitable for use in clean and ultra-clean environments, such as clean rooms and mini-environments facilities. The preferred diffusion panel of the present invention includes a diffusion membrane of a continuous mass of porous polytetrafluoroethylene bonded to one or more support screens of polymer mesh. The composite membrane and screens are mounted in a unique frame which eases the time and effort required for construction of the panels and which can be mounted to reduce vibration of the panel and leakage around its edges. This improved air diffusion panel also significantly filters small and sub-micron particles, resists chemical attack, and blocks liquid droplets.