Constant fusing pressure thermoplastic lid sealing apparatus and method

摘要

A lid sealing apparatus (30) and method for induction heat sealing a heat-sealable lid (15) to a can body (21). The lid sealing apparatus (30) includes a first conveyor assembly (34) having a plurality of independent, transversely mounted side-by-side support shoes (35) of relative rigidity collectively cooperating to define a segmented first surface (36) for supporting and moving the can (21) along a pathway. A second conveyor assembly (37) is oriented adjacent to the first conveyor assembly (34) and includes a relatively rigid second surface (40) in opposed moving relation to the first surface (36). A plurality of individual spring suspension mechanisms (43) are operably mounted to the frame (33) and provide moving support to each support shoe (35) as it moves along the pathway. Each spring suspension mechanism (43) individually biases the first Conveyor first surface (36) toward the second conveyor second surface (40) to provide a substantially constant fusing pressure between a can open end (20) and the lid (15) as the two travel as a unit. The plurality of individual spring suspension mechanisms (43) is sufficient in number relative to conveyor speed to hold the lid against the can open end for a duration allowing melting and the thermal fusion of the lid to the can open end. The lid sealing apparatus can be adapted for either a linear or rotary design.