Abstract: A plastic sheet packing or packing member of the flat folding bag type, primarily for pipe tobacco, the mouth opening of which is sealed in a welded manner enabling it to be opened without rupturing the sheet materials adjacent the mouth opening. The mouth is closed by a type of welding providing a good sealing effect though being releasable by mechanical pull to facilitate opening of the packing. The opposed surface portions of the mouth area may be welded direct to each other in this manner, or a separate, removable closing strip may be arranged along and across the mouth and secured by the releasable type of welding. This type of welding may require mutually different materials to be joined, and this is obtained either by the use of said separate strip or by using a sandwich sheet for the packing itself.

Abstract: A cementation apparatus is provided wherein the reaction surface thereof can be increased without changing the outer dimensions. There is provided at least one inner cylinder which is freely mounted in an outer cylinder and placed one within the other. The inner cylinders are perforated along their outer surfaces and are preferably open at both ends as is the outer cylinder. In the cylinder assembly, all the cylinders as well as the cylinder assembly are rotated. A slurry containing material to be treated as well as the amalgam is fed into the cylinders and on rotating the cylinders, the slurry is picked up by the surface of each of the cylinders so as to provide a reaction area for cementation which is equal to the sum of the surface area of all the internal cylinders and inner surface area of the outer cylinder.