Integrated Membrane Lamination and UV Exposure System and Method of Using the Same

Abstract

A combined laminating and exposing apparatus for exposing a photosensitive printing blank to actinic radiation in a printing plate manufacturing system and a method of using the same are disclosed. The photosensitive printing blank comprises a backing layer, at least one photocurable layer disposed on the backing layer, and a laser ablatable mask layer disposed on the at least one photocurable layer, wherein the laser ablatable mask layer is laser ablated to create an in situ negative in the laser ablatable mask layer. The exposing apparatus comprises: (a) a laminating apparatus for laminating an oxygen barrier layer to a top of the laser ablated mask layer; (b) a conveyor; (c) a first exposing device for imagewise exposing the at least one photocurable layer to actinic radiation, and (d) a second exposing device for exposing the at least one photocurable layer to actinic radiation through the backing layer.

Description

FIELD OF THE INVENTION[0001]The present invention relates generally to a combined lamination and exposure system for use in manufacturing relief image printing elements.BACKGROUND OF THE INVENTION[0002]Flexography is a method of printing that is commonly used for high-volume runs. Flexography is employed for printing on a variety of substrates such as paper, paperboard stock, corrugated board, films, foils and laminates. Newspapers and grocery bags are prominent examples. Coarse surfaces and stretch films can be economically printed only by means of flexography. Flexographic printing plates are relief plates with image elements raised above open areas. Generally, the plate is somewhat soft, and flexible enough to wrap around a printing cylinder, and durable enough to print over a million copies. Such plates offer a number of advantages to the printer, based chiefly on their durability and the ease with which they can be made.[0003]A typical flexographic printing plate as delivered b...

AI Technical Summary

Benefits of technology

[0027]It is another object of the present invention to allow for the simultaneous face and back exposure of digital relief image printing elements after lamination of an oxygen barrier layer to a relief image printing element.

[0030]It is still another object of the present invention to provide means of attenuating the actinic radiation in the back exposure step in order to reduce the intensity of the actinic radiation.

Problems solved by technology

It is very difficult to print small graphic elements such as fine dots, lines and even text using flexographic printing plates while maintaining open reverse text and shadows.

Maintaining small dots on flexographic plates can be very difficult due to the nature of the platemaking process.

The smallest of these dots are prone to being removed during processing, which means no ink is transferred to these areas during printing (the dot is not “held” on plate and / or on press).

Alternatively, if the dots survive processing they are susceptible to damage on press.

For example small dots often fold over and / or partially break off during printing, causing either excess ink or no ink to be transferred.

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