| 摘要 |
The invention relates to an arrangement for the sealing of thermoplastic-coated packing material of the type which comprises at least one layer of an aluminium foil. The arrangement comprises an inductor (13) connectable to a high-frequency source of current which is constituted of a U-shaped loop of electrically conducting material. The legs of the U-shaped loop are parallel and are situated close to each other, and the inductor (3) comprises between its legs a core (10) of ferrite material. The said core of ferrite material has local inserts (11) of ferrite material of substantially higher permeability than the surrounding portions of the core (10) and the local inserts (11) are installed in regions of the sealing arrangement where strong local heating is required in the sealing joint or where the sealing pattern needs to be influenced. |
