Improvements to stoppers for containers with surface- active products

摘要

They consist in the interposition, between the corresponding stopper 4 and the opening of the container 1, of a seal 2 of a compressible microporous type provided with a number of cuts and also the configuration in the inner roof of the actual stopper 4 of at least two different levels defined by projections 7 which alternate with depressions 6 which lead to the inner periphery of the aforesaid stopper, allowing communication of the gases or of air via said cuts from the non-compressed seal parts 2b and the tolerance of the screw thread 8 of the actual stopper, or vice versa. <IMAGE>