Process for filling and subsequent fusion welding of receptacles

A process for filling and sealing an at least partially elastically deformable container of heat sealable material, comprising the steps of:

• forming an elastically deformable container with a filler connection having a flow passage with cross-sectional dimensions smaller than a body portion of the container and an open end at a distal end of the filler connection;
• filling the container through the open end thereof to a first level of contents;
• raising the contents to a higher, second level inside the filler connection of the container by elastically deforming the container;
• in a first heat sealing step, reforming the filler connection to reduce the transverse cross-sectional dimensions of the flow passage by pressing flat and heat sealing a border zone of the filler connection after filling, the passage remaining open at the distal end thereof;
• in a second heat sealing step, closing and sealing the distal end of the passage after raising the contents to the second level;
• and
• between starting to raise the contents to the second level and starting the second heat sealing step, removing vapors, clouds or foams from an upper surface of said contents in the filler connection by suction by applying reduced pressure in the filler connection.