Slitter-Folder Rebuild

The Challenge

A large plastic film manufacturer needed to improve the throughput of several of their slitter-folders, and increase the quality of the finished rolls with minimal disruption to production in the finishing department. The end products, polypropylene and polyethylene, are widely used in the packaging and food industries.

Throughput on the machine was effected by unavailable parts due to the age of the machine. The outdated equipment also made it impossible to determine the amount of tension on the film, which resulted in inconsistent machine operation and roll properties.

The PCT Solution

PCT Engineered System's solution included using custom winder control logic in an Allen-Bradley PLC for controlling film tension. PCT also provided a complete electrical and mechanical rebuild including:

• PLC enclosure
• Drive enclosure with new digital DC drives
• PanelView touchscreen operator station with machine diagnostic displays
• Unwind operator station
• Three new DC motors
• New idler rolls and load cells to directly measure tension
• Revised taper tension control allowing operators to create a softer roll as requested by their customers
• New base to mount the motors and rewind frame, resulting in improved stability of the machine

Upon completion of the project, PCT was able to provide the customer with correct tensions resulting in improved roll quality at increased speeds. The new control system allows the operators to store and recall customer specific "recipes" for tension settings.

According to the customer,"... PCT contributed to a 30% increase in production with a 25% reduction in rejects and the operators love to run the machine (which is a real victory!)"

This project solution was then applied to additional slitter-folder retrofits with the customer and helped develop an on-going teaming relationship between the two companies.

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