Macchi S.p.A. will introduce the 2011 release of its Recotrim, which is designed to in-line process the side trimmings of plastic films generated during extrusion and convert them into dry, uniform and free flowing pellets.
According to the Italian company, the Recotrim features a patented system that is used to “grasp” the trim using a co-rotating twin screw that, while maintaining a low rotating speed, is able to grip thin or thick trims. When it is not processing trim, it can process roll stock for recovery using a custom in-feed hopper. The film is melted and plasticized in the screw and forced through a specifically designed extrusion die conceived with the same principle of the film dies and equipped with multiple holes for “strand” extrusion.
The 2011 release is also supplied with a totally new control panel based on a man-machine-interface realized with a Siemens 6″ color LCD touch screen linked to a Siemens S200 PLC unit. Macchi says the main features of this PLC control are to manage thermoregulation of the extrusion unit, melt pressure control and speed of the die front-cutting blades while providing alarm display.
With this new arrangement, in addition to usual setting operations, the new Recotrims now provide two operator-friendly automatic functions.
Synchro is a function that the operator can engage to set constant the shape and size of the pellets proportionally to the extrusion speed. This feature is useful during start ups or line settings.
Auto-Blades enables the production of a constant shape of the obtained pellets automatically, by sensing the extrusion pressure. This feature is useful when the trim feed is not constant, for example, when additional bleed trims are inserted or removed or when a single Recotrim is serving more extrusion lines.
Macchi claims that the simultaneous engagement of both functions guarantees the obtainment of a constant and uniform product, within all the output range – up to 40 Kgh – permitted by the unit.
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