As everyone is aware in this industry, print jobs being requested today are not only becoming more complex, but shorter in duration at the press. This means the printer must not only have a handle on print capabilities, but also successfully manage the press cleaning and changeover process for maximum efficiency.

The pressroom is the only place where money is made for the printing company, and also the only real place that money can be lost. All of the departments that precede the press: i.e., prepress, plate making, mounting, inks, etc., must provide the best possible materials to service that press.

All personnel must be educated in how the flexographic process works along with the terminology involved, the proper communication between departments, and effective use of documentation. Pressroom personnel must have the necessary knowledge of prepress technology to properly provide feedback to the servicing departments so both mechanical and technical errors can be addressed and avoided in the future.

The scheduler can have a dramatic effect on press-changeover efficiencies. Jobs with similar colors and deck orientations should be scheduled together whenever possible. Changeovers that involve going from surface print jobs to reverse print jobs should be limited.

Most of what has been mentioned to this point can be achieved with a minimum expense to the printer. Possible alterations or upgrades to the press, however, along with the possible addition of personnel, will definitely involve a financial commitment.

The most expensive option is to purchase a press designed and accessorized for maximum efficiency of changeover. This type of press would have tool-less anilox, cylinder and doctor blade changeover, auto racking, and either heavily utilized sleeve technology or robotics.

Even if the printer can afford one or two of these presses as he adds new equipment, he will have to use other strategies for his older presses. Most existing presses can be upgraded either with peripherals or componentry at a reasonable cost. These modifications include:

• Modify existing bearing caps for plate cylinders and anilox rolls for tool-less operation.
• Use removable doctor-blade chambers whenever possible.
• Auto racking should be considered for those presses with manual deck run-ins—an expensive option but one to consider.
• Teflon-coat all surfaces that come in contact with the inks, for ease of cleanup.
• Stock spare doctor-blade assemblies and pumps so they can be cleaned off-press while another job is being set up. With this system, it would be beneficial to add another press assistant as a floater in the press room to move from press to press as jobs are being changed. The more cleanup that can be done off-line, the quicker the changeover.
• Install dial indicators on the print decks for verifiable print settings. This greatly reduces setup downtime.
• A more expensive, but more efficient, option to aid in press cleanup is the addition of auto-wash capability for the print decks. There are a number of retrofit assemblies available that can clean all the decks at the same time, greatly reducing press downtime between runs.

Quick press changeovers require a combination of organization and communication between departments, as well as having the right components and tools at the press.

Steve Utschig

Consulting Technical Editor

920/735-4882

utschig@foxvalleytech.com