SYSTEM AND METHOD FOR EXPOSING A DIGITAL POLYMER PLATE

摘要

An improved process for producing flexographic printing plates using a digital workflow is described. After creating an in-situ digital mask over the photopolymerizable layer, the photopolymerizable layer is exposed to actinic radiation through the mask layer in a reduced oxygen environment. After subsequent development, the resulting relief printing form is composed of flat topped dots with crisp edges and steep bevel angles that can be used to print directly on corrugated materials.

主权项

1. A method of preparing a digital flexographic printing plate comprising:
(a) providing a photocurable printing plate blank including an uncured photocurable layer and an overlying mask layer capable of being laser ablated; (b) laser ablating the mask layer to create an ablated mask layer having an array of openings exposing portions of the photocurable layer corresponding to an image to be printed; (c) providing the photocurable printing plate blank of step (a) or of step (b) within a chamber; (d) prior to step (e), providing an inert gas mixture in the chamber in contact with the ablated mask layer and the exposed portions of the photocurable layer, the inert gas mixture not being under reduced pressure and containing oxygen in an amount less than 10.5%; (e) during step (d), subjecting the ablated mask layer and the exposed portions of the photocurable layer to a flood of actinic radiation, the actinic radiation passing through the openings in the ablated mask layer to cure the photocurable layer in the areas of the exposed portions; and (f) removing the ablated mask layer and uncured portions of the photocurable layer to create a relief image formed by a series of pedestals that reproduce the image.