Thomas J. Cocchiola, PE, CSP, Mechanical Safety Consultant ::::
Accident: A corrugated box plant owned and operated a rotary die cutter equipped with a leading edge feeder that repetitively inserts individual blanks through a feed opening. In operation, a helper loads a stack of corrugated blanks onto the feeder during set up and replenishes the stack during production. A set of rotating rollers within the machine housing pulls blanks through the feed opening.
An accident occurred while an operator and a helper were getting ready to start a production run. The operator energized the machine during set up without starting the feeder. The operator intended to energize the feeder after set up was completed. The helper saw a rag on a stationary feed table and reached to remove it before production began. The rag inadvertently entered the feed opening and got caught between the rotating rollers as the helper moved it across the feed table. The helper’s hand was pulled through the feed opening along with the rag and was trapped between the rollers.
Analysis: Fundamental engineering principles established acceptable dimensions for feed opening size/distance long before the rotary die cutter was manufactured. These feed opening design principles were subsequently incorporated into OSHA requirements as well as machine safeguarding standards and references. For safety purposes, the rotary die cutter should have been designed to prevent workers’ hands and fingers from reaching the hazardous rotating rollers.
An engineering analysis demonstrated the size/location of the feed opening did not conform to fundamental engineering principles and safety requirements. The analysis also determined that effective guarding was feasible, practical and economical. The accident would not have occurred if the feed opening was effectively guarded.
Results: The case was successfully resolved.
Thomas J. Cocchiola, PE, CSP, is a Mechanical Safety Consultant with DJS Associates and can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.