HepcoMotion® Linear Actuators Boost Safety at Packaging Plant

The 150-employee Mondi site at Scunthorpe specialises in co-extruded polyethylene films and performance laminates, with focus on high quality flexographic printing dedicated to the supply of a wide range of food and non-food applications. Many of these products feature a slit line that needs to be in a precise position during manufacture, typically on a converting machine. Converting machinery takes a web of plastic film, cuts it into lengths and fuses the edges, thus converting it into plastic bags. This activity is known as web processing.

“Previously, the position of the slit line was adjusted by hand,” explains Engineering Manager, Rob Smith. “Although we haven''t had any accidents, as a company we are always keen to deliver projects that impart greater preventative safety measures. Clearly, the implementation of physical safety guards on our converting machines would be restrictive to our daily operations, so we needed another solution.”

Mr Smith and his team came up with a concept that featured an optical eye mounted on a motorised sliding rail. The rail would allow the movement of the sensor to the edge of the web within the machine''s perimeter fence, thus keeping operator arms out of the danger area. However, the next issue was how best to turn this concept into reality.

HepcoMotion® recommended PSD80 [80mm] screw-driven linear actuators in an open design with a 4mm leadscrew pitch. The size and space envelope of the PSD80 was good for the application and the open unit provided a competitive solution that was easily integrated into the machines. The units were also delivered against a strict deadline.

Offered to Mondi Scunthorpe with a 1725 mm beam length, HepcoMotion® also provided an easy-to-use connection kit for use with third party motors and drives.

Two converting machines are complete, both now offering fully functioning optical eye/motorised sliding rail safety features. Mondi Scunthorpe is currently in the process of upgrading two more machines, this time using two single PSD units back-to-back. The double-acting configuration is required as the machines differ from the first two in that the sensors need to track both left and right edges.