Discover how digital cutting systems work and how various models differ.
By Lori Leaman
Among the types of blades available, the two most commonly used in digital cutting systems are supersteel and sapphire. According to Neal Baessler of Graphtec America, supersteel blades are suitable for general cutting applications. He says sapphire blades are especially suited for cutting Rubylith for screenmaking. "It cuts through the film without having to score the backing, which often causes refractions when you are exposing a screen," he says.
Many flatbed cutting systems are equipped with tool inserts to support a variety of cutting functions. Kiss-cutting blades are available for pressure-sensitive vinyl films to cut the film with cutting the backing liner. Oscillating knives are used for corrugated materials, foam, and folding carton. Tools for creasing, engraving, routing, and pen plotting also are available. Pen-plotting tools, originally designed for AutoCAD applications, can provide screen printers with a way to demonstrate to a client what a finished sign will look like when it's cut.
Some cutting systems use servo-motors to drive blades and material-feeding mechanisms. The servomotor is a closed-loop system in which the motor's controls constantly monitor the motion and distance of the carriage head. On some systems, namely sprocket-fed cutters, you'll find stepper motors, which are less expensive than servo motors and are not equipped to monitor the carriage head's movement. Rivera notes that servomotor-driven cutters have improved speed and cut quality over the years, especially in applications that involve complex curves and arcs. He says stepper motors can leave jagged edges on complex curves.
Cutting force and speed
Cutting plotters, depending on the brand and model, support media in widths ranging from 15-55 in. and cutting widths between 13-52 in. Several large-format systems also are available that offer cutting widths from 72-126 in. Desktop cutters are another option and support cutting widths between 6-14 in. (Figure 4). Most systems offer cutting forces up to 600 g. Some large-format flatbed systems can deliver a maximum cutting force up to 5000 g.
Cutting speeds on flatbed systems are as high as 55 in/sec, while roll-fed systems typically deliver speeds between 30-40 in./sec (some systems, however, can reach speeds as high as 60 in./sec). Speeds on desktop systems usually top off at 6 in./ sec, though a few models can cut faster than 20 in./sec.
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