Abstract: A firm container is fed with a plastic material which surrounds the firm container along a portion of its length. The firm container has an open end which is closed off by a pair of welding jaws which welds the plastic material together and forms the bottom of a container that holds a pulverized material. Pulverized material is then fed to the bottom of the container and after feeding is over, the plastic material is allowed to fall from the firm container by moving a support table downwardly. After the support table has moved downwardly a certain distance, the welding jaws are operated again and weld a new piece of plastic material to the open end of the firm container, thus forming a bottom for a new container and closing off the top of the previously-made container. A piston is provided within the firm container for compressing the pulverized material fed into the interior of the firm container.