Description of the proposed system:
The in-feed section would accept input from a single conveyor on which the products would arrive in single lane after inspection. This inspected product will transfer from inspection conveyor to the in-feed conveyor of the machine
Sealing and Film Feeding Section
The Shrink Wrapper uses one center folded roll of film. Rolls have gravity unwind with provision to feed out.
The sealing system comprises of a hot knife design with special coated for P.E. films.
When product passes through the in-feed conveyor and reach to sealing area sensors senses the product and passes the signals to the pneumatically operated sealing bar. Therefore, the cylinder retracts and sealing jaw comes down. After the seal is made, it retracts. Cool air is thrown on the seal to achieve a strong seal. Once the sealing is over, the out-feed conveyor takes the product inside the Shrink Tunnel.
This will transfer the first set of loosely wrapped packs into the tunnel, where the shrinking process will take place, in this way the cycle continues.
The Shrink tunnel is used to circulate hot air around the pack as it moves on a conveyor. The air from the inside of tunnel is sucked and blown on the heater. Heaters are finned types. This re-circulating air then comes on the pack from all sides, top and bottom thereby giving a uniform shrink.
Temperature controller is PID (digital from Omron). During the first quarter of the tunnel, the film gets hot air only from the bottom and then from all sides. This helps in shrinking film well.