Method and apparatus for digital pad printing

摘要

An improved method and apparatus used in pad printing is disclosed wherein a customized cliché is created from a generic cliché and a computer image of the desired printed output. The generic cliché contains a fine array of micro pockets on its inking surface. Ink jet printing ink is precisely deposited into the micro pockets at varying locations and amounts by the computer system and cured to harden the ink jet ink, which creates a customized cliché. Pad printing ink will adhere to the customized cliché in amounts in inverse proportion to the amount of ink jet printing ink deposited and cured on the customized cliché. The pattern of empty, partially filled and completely filled micro pockets in the customized cliché creates a gray scale image on the printed part.

主权项

1. A method of pad printing, comprising:
(a) providing a generic cliché defining a first surface configured to contain a plurality of micro pockets conforming to a graphic design desired to be transferred to a substrate; (b) creating a customized cliché by precisely depositing varying amounts of ink jet ink into at least some of the micro pockets in the generic cliché representing areas of the graphic design requiring gray scale tonal control to be printed on an eventually completed part; (c) curing the ink jet ink to solidify the ink jet ink; (d) applying a quantity of pad printing ink to the first major surface of the customized cliché; (e) contacting the customized cliché with the pad printing ink, filling in the micro pockets with amounts of the pad printing ink in inverse proportion to the amount of cured ink jet ink previously deposited in each pocket; (f) further contacting the customized cliché with a printing pad to transfer the graphic design from the customized cliché to the printing pad; and (g) moving the pad printing inked printing pad to contact the substrate, thereby transferring the graphic design; (h) drying the printed substrate; and (i) following the printing cycle, cleaning the printing pad to prepare for the next cycle.