Rotary Die Cutter

Overview

A rotary die cutter cuts and creases shapes out of moving web or sheet stock by rolling a die against an anvil, instead of stamping with a flat reciprocating die. Because the cut happens continuously in a nip rather than in stop-start strokes, it runs far faster and suits labels, folding cartons, gaskets, and light corrugated blanks. The flexible magnetic die used here is a thin etched steel sheet wrapped onto a cylinder, which is cheap to make and quick to change compared with a solid rotary die.

The cylinders run in the rigid Frame & Side Plates, and the Main Drive turns the whole train together so cutting and anvil surfaces stay in mesh.

How it works

Stock enters through the Infeed & Feed Rollers, whose driven nip rollers meter it into the nip at the cylinder's surface speed so the web is neither stretched nor bunched. At the Cutting Station, the Magnetic Die is held by magnetism to the cutting cylinder and pressed against the hardened Anvil Cylinder; as the stock passes between them the raised rules shear the outline and crease the fold lines in one rotation. Adjusters set the cylinder gap to control cut depth without nicking the anvil.

For pre-printed stock the cut must land on the print, so the Registration servo and encoder read a printed mark and micro-advance or retard the cutting cylinder to hold register. Past the cut, the Waste Stripping station lifts the waste matrix and trim away with pin rollers and a winder, leaving clean blanks that the Delivery belt decelerates and stacks. The Control Panel coordinates line speed, register correction, and stripping from a single graphic interface.