Patent Speeds Sheeter

Maxson Automatic Machinery says a study of fluid mechanics helped it figure out how to speed up its sheeter. The devices are used as an infeed for roll-to-sheet presses and at delivery for webs.

Maxson developed the Airfoil Overlap system to increase the sheeter speed by 200 fpm at the point where sheets are delivered from the cutter. The use of fluid mechanics rather than mechanical components in overlapping sheets reduces the possibility of marking a sheet pile delivered from multiple webs, as well as reducing static build up and maintenance requirements.

The system works by aiming constant streams of pressurized air (around 75 pounds per square inch) from the Airfoil's manifold, flowing it over a stainless steel doctor board plate (curved arrows) and up the curved profile of the Airfoil's tail. As the air washes across the surface of the plate (vertical arrows), a vacuum is created pulling down the trailing edge of the sheet pile. The air is then directed perpendicular to the flow of the oncoming sheet, blowing the leading edge up.

If it is outfitted with a booster valve, the Airfoil requires no adjustment—regardless of line speed or sheet length changes, says Maxson. Also, the overlap unit is compact enough to allow for retrofitting. maxsonautomatic.com