High-output line targets CPP film

A new production line for cast polypropylene (CPP) film can produce high-quality, transparent film in seven-layer structures at output rates of 300 m/min. The unit, Midex 7-150/90/80/4x60-2500, consists of seven extruders (150-, 90-, 80-, and four 60-mm units), a seven-layer feed block, as well as a company-developed flat die (BSD-CR04-2400) with thermobolts. It includes encapsulation on the sides to reduce scrap production and promotes edge trim recycling which can be fed back into one of the extruders for optimal processing at lower costs. Throughput is up to 1000 kg/hr, the film width is 2000 mm, and web thickness can vary from 0.012-0.250 mm. The unit targets PP markets such as barrier packaging, metalized PP films, lamination web produced in either PP or polyethylene, and stretch film.

Michael Beckhoff, general manager cast film and coating lines, says the unit allows remote diagnostics via the company's VPN (virtual private network) system accessed through the Internet to help prevent downtime of a processor's line.

Rounding out the CPP line offering is an optimized rotary-arm winder, WF-D04, for winding rolls up to diameters of 1000 mm. In a gap mode, the winder includes web tension control which works in conjunction with the roll drives and is able to influence winding density of the film. Winding speed is just under 250 m/min. In the contact mode, which also includes an element to control contact pressure, CPP film winding is up to 300 m/min. In this mode, the high friction of the contact roll ensures straight reel edges while the low adhesion of the contact roll avoids the need for additional electrostatic film pinning.

Beckhoff says the hard contact-roll surface reduces wear and the open-loop control ensures a uniform reel buildup. Reel hardness is influenced by two parameters (winding tension and contact pressure), which results in high winding speed and good roll quality. Reifenhäuser GmbH & Co. KG Maschinenfabrik, Troisdorf, Germany; +49 2241 481163; www.reifenhauser.com