| abstract |
The invention describes new designs of commercial inkjet or flexographic web and sheet fed presses with pre-coating prior to printing which may upgrade the quality of the substrates and render them printable by all printing technologies including inkjet and digital. Also described are curable water-based coatings, inkjet and flexographic inks and overprint varnishes which may be radiation cured at high speed without the need for external applied heat to remove water. When used as coatings or primers, the compositions of the invention may create a surface on cellulosic substrates, polymeric films and some metal surfaces which are suitable for printing on by most printing methods including but not limited to inkjet, wet and dry toner systems, lithographic, gravure, flexographic and 4-D printing. The primer/coatings may also add up to 35% tensile strength to lightweight "thin" papers. The primer/coatings, inks and overprint varnishes can be cured by UV with or without the need for added commercial and/or conventional photoinitiators and the same formulations can be cured with electron beam using less than 35% of the energy required for conventional EB coatings and inks and without the need for a nitrogen environment thus allowing EB cure sheet fed printing. The primer/coatings of the invention may allow multi-colour printing on lightweight papers by conventional water-based inkjet inks that could previously not be printed with this method. Overprint varnishes of the invention can be applied successfully in-line on the printing press over wet inks before being EB or UV cured. |