Tensioning Mechanism of Thermal Head in Pulse Heat-sealing

The aim of this study was to solve the problem of poor quality caused by expansion and contraction of the nickel-chromium alloy in pulsed heat-sealing process of large-size film. The problems occurred in the pre-production stage were analyzed, the main parameters of the tensioning mechanism were determined by combining the theoretical calculation and experiments, and two tensioning mechanism physical prototypes were designed and developed. And then the advantages and disadvantages of these two tensioning mechanisms were summarized through debugging and analysis of physical movement. The trial of the prototype showed that both tensioning mechanisms could play a tensioning effect under the respective conditions, and could be selected according to the actual situation, which achieved the purpose of design, and addressed the problem about the expansion and contraction of nickel-chromium alloy in pulsed heat sealing. When the tensioner type II was attached to the ends of the head structure in 4 m pulsed heat-seal machine, the tensioning effects of nickel-chromium alloy were significantly improved, the poor heat-sealing quality problem caused by thermal expansion of the nickel-chromium alloy was eliminated, and the downtime losses caused by the fault of heating component were reduced,thus improving the production efficiency.