Modified MDO Gives Higher Film Yields

Hosokawa Alpine American, Natick, Mass., is offering new machine-direction orientation (MDO) technology that is said to dramatically reduce the amount of film to be edge-trimmed compared with other MDO designs. Called TRIO—for Trim Reduction for Inline Orientation—the new system works in conjunction with Alpine’s automatic gauging technology (AutoTherm segmented air ring) to minimize neck-in, which sometimes requires up to 20% of the film to be trimmed after orientation.

In a typical MDO system, the pulling and stretching effect of orientation results in thick spots forming on the film edges, which must be trimmed, and thin spots in the middle. In the case of high-barrier food packaging, the edge trim can be reprocessed only in limited amounts, if at all. Moreover, thickness inconsistences in the remaining usable film result in a bowing or cambering affect that affects converting.

With the TRIO, a second thickness gauge mounted after the MDO station is linked to the auto air ring to help pinpoint where the film edges will eventually wind up and thereby thin out the thick spots before they form. This is said to reduce by up to 50% the amount of film to be trimmed while making the remaining material more uniform in thickness.

Alpine has sold 10 such systems outside North America, three of them retrofits to existing MDOs. Two undisclosed film processors bought more than one unit.