Delivery section of a web-fed press with inline cutting.
In-line die cutting and rewind section of a press.
Cutting of the printed substrate may occur as a finishing step either inline or offline. For web printing, cutting often occurs inline at the end of the printing cycle and may be coupled with folding. In sheetfed printing, cutting occurs offline. Several types of cutting equipment are commonly used in lithographic printing including sheeters, die cutters, and guillotine cutters.
Die cutting is a process of using sharp steel rule to stamp out a specific shape or pattern into the substrate. Die cutting systems for lithograph printing are off-line operations where the substrate sheets are cut individually, stacked onto pallets, and transported to other stations to be trimmed and/or separated.
A guillotine cutter is composed of a long, sloping blade that descends onto a table or bed and slices through a stack of paper. The components include the knife, cutting stick, cutting table, side and back gauges, and a clamp. Guillotine cutters can be used to trim the edges of a printed sheet. A three-knife trimmer is a variation on the guillotine cutter that uses three knives to trim all three sides of a bound signature at once.
Sheeters are used to convert continuous rolls of substrate into sheets. Sheeting can be done in-line to convert a printed web into sheets, or the web can be rewound and sheeted on an offline sheeter. Offline sheeters are also used prior to printing in facilities that purchase their substrate in rolls but print with sheetfed equipment.
Best Management Practices & Pollution Prevention
Cyclone baler, showing waste partially separated into bales according to color and paper type. Whenever possible, bales should be completely separated.
After cutting the substrate using a guillotine or die cutter, the waste portion of the substrate is separated and collected. Typically this is collected using a cyclone-baler system, which is ducted to the cutter. The vacuum created carries the trimmed paper to the baler where it is baled and later sent for recycling. Other trim scrap collection systems involve rewinding the trim scrap onto another roll core or routing the trim scrap through shoots made out of PVC into rolling totes. The scrap is then manually fed into a baler or shipped off site in totes.
Carefully designed printing layouts and cutting dies can help minimize the amount of scrap trimmed from the product. This will minimize waste, substrate costs, and increase press efficiency by printing more product in less time by maximizing the number of copies printed with every turn of the printing cylinder.
For access to vendors who may supply alternative materials and equipment, see the PNEAC Vendor Directory.
In some state and local governments, businesses (printers) may be subject to waste minimization requirements and recycling requirements.
Health & Safety
Care must be used when handling and installing dies onto the press. Wearing gloves will help prevent cuts to hands or nicks to the die. Extreme care must also be taken when the press is running and the dies are rotating. Personnel must keep hands and loose clothing clear of the rotating die. Stop the press completely before clearing any items that are caught or stuck in the die nip.