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Polytype machine rotates mold instead of tilting it

Issue: January 2017

At the K show, Polytype OMV, of OMV Machinery srl, Verona, Italy, showed its RM77 Revolver thermoforming machine in production for the first time. While still under construction, it had been introduced as a prototype concept at NPE2015.

“During construction, we simplified the stacking system,” sales manager Claudio Menini said. “The machine was completed and tested in 2016.” He added that it was tested for more than six months.

Polytype OMV’s RM77 Revolver in action during the K show, where the new thermoforming machine used its 51-cavity revolving mold to produce PP cups. The machine’s patented rotating mold system is designed to compete against tilting technology.

The company is marketing it as “the fastest on the draw.” Polytype is represented in the North American market by Polytype America Corp. The machine got a lot of attention for its aesthetic appeal; onlookers could see its revolving 51-cavity mold through a window as it produced PP cups. Its patented rotating mold system is designed to compete against tilting technology, and officials say it has the capability to produce up to 165,240 cups per hour when it is cycling 54 times per minute with 51 cavities.

The machine can form thick- or thin-walled containers, products that have critical tolerances, and materials that need a longer cooling time, such as PP or multilayer sheet.

The machine assembly includes one movable upper male part and two lower rotating female tools. The lower rotating platen is propelled by a high-powered torque motor. The oven has a six-step, or six-index, C-shaped design that has ceramic heating elements on the top and bottom. These elements are arranged longitudinally and controlled electronically. The forming area of the machine has a width of 30 by 19 inches; each time the press opens and closes, the sheet goes forward about 19 inches, or one index or step. This means that the part of the sheet entering the press has been heated six times before being formed. The oven length is 118 inches, or roughly 19 inches times six.

Overall, the system is very automated, Menini said. Indexing, platen movements, plug assists and stacking all are controlled by servo motors.

The machine can run several types of resins, including PS, PET, PE and polylactic acid. The forming station and the automatic product handling are designed for multiple row molds in an in-line or staggered layout. The system overall is controlled by a smart drive control with controlled access to all machine functions by HMI.

The machine also has a quick mold-changing system. The stacking device is mounted on rails to be moved away; the lower platen, therefore, is easily accessible, and the upper platen can be slid onto a side table.

The first machine has been sold to a European customer, Menini said.

Angie DeRosa, managing editor



Polytype America Corp.,