a heat sealing assembly , for sealing thermoplastic film , comprising first and second jaws , an electrical impulse heat sealing element , electrical terminals , and an electrical and thermal insulating material between the first jaw and the heat sealing element , said heat sealing element being removably connected to said electrical terminals , at least one of said jaws being capable of transverse motion and adapted to collapse a tubular film made from said thermoplastic film and passing between said jaws , wherein said element has at each end an electrical contact male plug oriented at about 90 degrees angle from said element , said plugs being parallel to each other and having a shape which allows each to be received in correspondingly shaped sockets , said sockets being held by spring means adapted to apply force in tension to said element when said plugs are in said sockets , said plugs being adapted to fit into said sockets when said spring means are deflected toward said element , and wherein securing means for preventing arcing between the corresponding plugs and sockets are provided .