| abstract |
Disclosed is a method and apparatus for sealing together two generally cylindrical thermoplastic members, each having a longitudinal axis, an open end and a closed end, so that upon being joined they form a sealed capsule that may be swallowed. One capsule member may be snugly inserted into a vibrating cavity with the opened end of the member available to be filled with an active composition. The other member is placed over the first member and pushed downwardly so that the open portions of both members overlap one another. The overlapping portions of the wall members abut each other at a cylindrical interface band. Vibration causes only the overlapping wall portions of the members to rub together, thereby generating heat around the interface band. The heat, so generated, melts enough thermoplastic material at that band to produce, on cooling, a strong circular bond between both members. |