For testing filled closed packages of flexible material for leaktightness use is made of an apparatus provided with conveyor means (2) for feeding packages in line and with means for applying pressure to the packages. The last-mentioned means consist of two pressure belts (4, 5) disposed a short distance...http://www.google.com.au/patents/US4697452?utm_source=gb-gplus-sharePatent US4697452 - Apparatus for testing the leaktightness of filled, closed packages of flexible material
