Nowhere in the packaging process is the handling of the product more susceptible to damage than in the wrapper infeed cycle, resulting in high defect rates, lessened throughput and increased production costs. This is common particularly with shrink wrapping where mis-wraps can easily occur, jamming the line. When shrink coverage does not completely cover the product, it can go unnoticed until later when the product has spoiled due to exposure. Improper sealing is primarily caused by poor infeed and misregistration.
To achieve a much more consistent level of registration and wrapping integrity, a system called ServoSmartFeed® is now being used by many companies with indexing conveyors, automatic L-sealers, horizontal form-fill and seal-flow wrappers, and over-wrappers. Servo-SmartFeed, also developed by Shuttleworth, working in combination with Slip-Torque conveyors, links wrapper infeed to upstream product flow. It is designed to dynamically accumulate and synchronize the release of products into a wrapper or packaging machine without stopping the product flow. Products on the system are always in motion while the downstream equipment is operational.
SmartFeed operates by timing the release of product into the flighted infeed on the wrapper with a pneumatic/electric gate. With a speed-up zone near the discharge end of SmartFeed, one product at a time is placed onto the infeed of the wrapper. The spacing is very precise, a tolerance of 0.25 inch to 0.5 inch. SmartFeed is in synchronization with the wrapping machine using encoder feedback from the wrapper. A sensor identifies each product’s location, and then the conveyor will either accelerate or decelerate the product to place it into position on the flighted infeed of the wrapper.
The system operates in four speed-registration zones to manage the infeed of products: 1) the first zone accepts the product from upstream manufacturing such as a freezer, oven or staging point, then conveys it downstream; 2) the second zone closes the gaps between the product, running the food product back-to-back; 3) the third zone increases the spacing between the products equal to the pitch flight on the wrapper; 4) and the fourth zone positions each individual food item into the gaps between the flights.
The automatic wrapper and SmartFeed are always talking to each other and reacting to whatever products are moving through the line. When there is a delay with an item, SmartFeed tells the wrapper that no item is in position, and to slow down or stop. When the next item is in position, SmartFeed tells the wrapper to start, providing there is accurate indexing of the product to be wrapped. Servo-Smart Feed creates an integrated system monitoring the flow of product right through to the wrapper. Controls installed upstream regulate the speed of the line throughout, directed by SmartFeed.