DMC and our customer developed this system for the distribution center of a large grocery chain. Packages of produce must be grouped together and sealed with a preserving gas. The food distributor previously used several small, individual packaging machines and intensive manual labor for this process. The new system is conveyor-based and provides much greater throughput.
Packages of product travel down the conveyor in small groups. Sensors on the conveyor count the packages and measure the gap between groups. The measured gap is automatically adjusted to the ideal size by varying the conveyor speeds (undersized gaps are stretched and over-sized gaps are compressed). This reduces scrap and improves consistency. Packaging material is unrolled at a speed matching that of the conveyor. The material is wrapped around the product and then sealed and cut while preserving gas is injected. An algorithm monitors a dancer next to the roll of packaging material and makes adjustments to compensate for the changing diameter, allowing roll speed to be synchronized with the rest of the system.
The user interface provides cycle counts, production times, error handling and logs, and allows adjustment of job and system parameters. It also calculates and displays the optimal machine speed based upon the incoming product rate as a guideline to the operator. Debugging tools are provided, including several test modes and screens for monitoring and forcing I/O.