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The Slice is Right: A Guide to Cutting-Equipment Selection

(August 2002) posted on Tue Sep 03, 2002

Learn about the types of cutting systems that are available, the capabilities each variety provides, and the production issues you need to consider before selecting a system for your operation.

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By Tom Kleeman

Rotary diecutting systems are designed for processing roll-fed material. The tooling on these systems consists of a cylinder that rotates and cuts as material is fed between it and the surface of the press. While rotary systems can offer very high cutting speeds, their cut-to-print accuracy is also limited by the fixed nature of the tooling.

When cut-to-print registration tolerances are tight, image distortion due to printing irregularities (e.g., screen stretch during printing) or substrate dimensional changes (material stretching or shrinkage due to processing or environmental conditions) make it nearly impossible to get the required cutting accuracy from large-format diecutting presses. For these jobs, gap diecutting presses that use electro-optical registration technology and digital cutting systems that don't require fixed dies (i.e., cutting plotters and lasers) are the devices of choice.

The laser cutters and cutting plotters are often the preferred route for shops that deal in short-run cutting jobs or companies that need an effective solution for prototyping. The main advantage of these machines is their repeatability in terms of cutting accuracy. However, unless these devices incorporate vision-registration systems, they have no way to compensate for image or material distortion and gauge where they are cutting relative to the print area. These machines also have some other drawbacks compared to conventional diecutting presses in that they cannot crease materials and may be more limited in the range of materials they can cut (adhesives, for example, tend to be challenging for them).

Optically-registered mechanical gap diecutting presses using either steel-rule dies or hard tooling are hybrid systems that combine the speed of diecutting with the accuracy of a digital cutting system. Gap presses offer high-tonnage cutting in a narrow gap between the tooling head and the press bed.

Unlike clamshell or flatbed presses, gap-diecutting machines have a more limited cutting area and cut far fewer pieces per cycle (usually 2-4 pieces). However, when these presses are equipped with electro-optical sensors and fully automated material-handling systems <B>(Figure 1),</B> they provide minimal labor costs and economies of operation that are equivalent to conventional diecutting equipment. Optically-registered gap presses don't just provide greater accuracy, they are also far more flexible in terms of the range of materials they can handle and the special features they can create, such as creases, embossed areas, and perforations.

Cutting-system selection and run length


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