G.F. Puhl Company and Sonoco recently teamed up to solve a challenging scrap handling dilemma: How do you design, install, and commission a scrap handling system for a production line that supplies food can products throughout the western hemisphere – and almost never shuts down?

The result is a custom designed one-of-a-kind scrap handling system that evacuates whole paper-based food cans ejected from multiple production lines and multiple pickup points on each line. Cans range in size from approximately 4 inches to 12 inches in length. During the can master tube production process, the G.F. Puhl scrap collection system also picks up trim rings at multiple pickup points. In total, the system collects materials at more than 40 scrap collection points. 

As a condition of purchase, this system had to be installed while the plant was in full production. But that wasn’t the only requirement. In the existing system, each collection point was serviced by bins on wheels that were manually pushed to a bin dumper loading into a baler. Sonoco wanted the collection hoppers on the new G.F. Puhl system to maintain the same or smaller footprint compared to the existing rolling bins.

The new collection hoppers had to be easily switchable back to the old system in the event of a breakdown. In addition, the G.F. Puhl system had to deliver the scrap cans and trim rings to the same baler that was using the dump cart and conveyor while the baler was in production. 

With careful planning, skilled engineering, and close collaboration, G.F. Puhl and Sonoco completed the installation with minimal downtime. The benefits were immediate. The G.F. Puhl system reduced energy consumption and cost Vs a conventional air conveyed system by utilizing a sequential system opening the vacuum at the collection points only on an as-needed basis while maintaining conveying velocity and pressure balancing throughout the system. This innovative design reduced total system size and CFM by approximately 60 percent. 

The whole-can sequential system was designed by G.F. Puhl’s engineering team and tested in G.F. Puhl’s fabrication shop. Approximately 30,000 cans were conveyed through the test system and observed by Sonoco engineers for their input and approval prior to system fabrication. 

Because the product is critical to Sonoco’s operation and very minimal downtime is acceptable, the G.F. Puhl design features a backup system that automatically engages when the main system is on maintenance. In addition, all the conveying air is filtered through two filters and returned to the facility at near hospital grade particulate levels.  

The Sonoco system includes PLC controls and a remote production floor control panel to facilitate operations. System controls monitor when the cans are being ejected to eliminate any jamming issues during the sequential valve cycling process.  

In a complex scrap collection scenario like this one where so much is at stake, collaboration is key. G.F. Puhl partnered with Sonoco every step of the way. Thanks to an unwavering commitment to teamwork by both parties, this project achieved all its goals.

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