Servomotors Increase Output in Web Presses

As bright as Johannes Gutenberg was when he came up with movable type in 1454, he probably couldn't have foreseen the advances we've made since then in putting ink on paper. Today's high speed web presses churn out catalogs, brochures, newspaper supplements, preprinted forms and other sorts of printed pieces at more than one thousand copies a minute, materials that lubricate our economy by putting needed information in front of interested readers. But once that web of paper is printed, it has to be cut to the right length for it to be useful - a sheet of continuous paper thousands of feet long is obviously not a convenient size for reading or mailing. And that's where a piece of equipment called a sheeter comes in. This mechanical marvel takes that web of paper and cuts it into sheets of a specific length. It doesn't sound very complicated, until you actually see one running at 1000+ feet per minute. Then you wonder how it could run at all. It's a maze of wheels, pulleys, gears, belts, mechanical fingers and a very impressive cutting cylinder moving so fast you cannot see the razor sharp knives mounted on it. And it's these cylinder-mounted knives that do the real work here. As the web of paper is drawn into the sheeter by the infeed roller, it passes under the rotating knife on the cutting cylinder. In an action resembling a scissors, the paper is squeezed between the knife cylinder and another knife blade mounted on the bed of the sheeter. Voila! In less than a hundredth of a second you have a neatly cut sheet, ready for follow-on operations like stacking, folding, etc. The sheeter can be equipped with optional slitting knives that cut the web along its length, thereby producing multiple cut sheets for each cycle of the cutting cylinder.