LINCOLNSHIRE, Ill. September 11, 2007 -- Makeready is what happens on a particular press between the printing of the last good product sheet for one job and the first good sheet of the next job. For printers that perform lots of makereadies in a day, the minutes required to execute the various mechanical tasks add up. Mitsubishi's SimulChanger targets the time-consuming plate-changing steps in makereadies.
SimulChanger is Mitsubishi's fully automated, simultaneous plate-changing system. Optionally available on new Diamond series presses, it is capable of replacing old plates with new plates at every printing unit in one seamless operation. On multicolor presses, SimulChanger allows plate changing on all printing units at the same time without the operator being present at the printing unit. SimulChanger can complete a plate change on all units in approximately one minute, regardless of the number of units involved.
Sheet transfer through the press is accomplished by a series of impression cylinder and transfer cylinder grippers. Gaps on the plate and blanket cylinders produce shock if they come into contact with grippers on impression cylinders. Cylinders are positioned to rotate so that the gaps do not arrive at the same time. Positions of the cylinder are different for each printing unit when the press comes to a complete stop.  For this reason, each plate cylinder must be positioned individually during plate changes.
SimulChanger's simultaneous plate cylinder phasing system makes use of the uppermost and lowermost adjustment settings for registration. Plate cylinders at each unit automatically turn and stop at the optimum positions for changing plates. This arrangement enables the plates at all units to be changed at the same time. Once the plate change is completed, the cylinders return to their proper phase for printing.
From a standing position, operators load new plates into cassettes while the press is running. All other functions of the plate change, including automatic and simultaneous deplating of multiple units, are carried out with the touch of a button at the Mitsubishi COMRAC press control console. Preloaded plates are taken up and mounted automatically as the old plates are ejected. Positioning of the cylinder, clamping and tensioning are automatically accomplished.
Compared to the typical 90-second replacement time on each unit, SimulChanger alone can reduce makereadies on a 10-color press by almost 15 minutes. The push-button system and reduced manual exertion also minimizes operator fatigue.
Mitsubishi Lithographic Presses will demonstrate the fast plate-changing speed of SimulChanger operating on the eight-color Diamond 3000LS sheetfed press in booth #617 at Graph Expo 2007.