Abstract

The manufacture of non-returnable packages for e.g. milk is frequently carried out by the conversion of web-shaped, laminated packing material to a tube, filling of the tube with milk and sealing and forming to filled packing containers of the desired, e.g. parallelepipedic, shape. During the forming, which is done by means of external forming devices, the contents are made use of as an internal mandrel or a holder-up for the forming devices, so that the desired shape can be achieved without creasing or other deformations. The above-mentioned forming principle works less well if the packing containers are not to be completely filled but have a certain air space or headspace. The proportioning of the contents also becomes uncertain and the desired accuracy of volume cannot always be achieved. These difficulties are overcome if the contents are mixed prior to filling with gas, preferably sterile air, in appropriate proportions, so that the contents obtain a foam-like character, using a gas volume which is in a suitable proportion to the air space of the finished packing container. The invention relates to a method and apparatus for proportioning the contents in the manufacture of packing containers.