In the packaging machine industry, wrapping machines are based on a ring that rotates at high speed, spreading the polyethylene film, which is dispensed by the pre-stretch units, around the pallet.
By reducing the weight of the ring and the entire rotating unit, the speed and, consequently, the productivity of the machine can be increased.
There are two pre-stirring units of considerable weight, (more than 40 kg when fully loaded), which are mounted symmetrically and cantilevered on the ring. During rotation, they apply considerable stress on the ring and can induce vibrations that are transmitted to the entire structure and can limit the machine’s performance. The support ring must therefore be very strong.
The entire assembly must also be able to start and stop very quickly, so it can reach a steady speed and also for safety reasons, in the case of operator interference or other errors. By decreasing the weight of the rotating assembly, inertia can be reduced and the task simplified.
We met the challenge by bringing aeronautical expertise, useful for machines that have rotational speeds approaching those of helicopters, and more than a decade of experience in packaging machines. The ring was laminated in a single piece of carbon fiber, a material that is both stronger and lighter than metal. The sizing study made the ring extremely strong and able to better withstand stress and vibration.
Reducing the weight of the rotating complex allowed us to redesign the entire machine around this component, reducing the overall weight, streamlining the supporting structure, lowering power consumption, and achieving greater safety. The systemic vision and expertise in reengineering the entire machine around the key component allowed us to decrease construction and operating costs, gaining a (competitive) advantage over our competitors.