Indirect printing apparatus employing sacrificial coating on intermediate transfer member

摘要

An indirect printing apparatus is disclosed. The printing apparatus comprises an intermediate transfer member. A polyurethane based sacrificial coating is on the intermediate transfer member. The printing apparatus also comprises a coating mechanism for forming the sacrificial coating onto the intermediate transfer member and a drying station for drying the sacrificial coating. At least one ink jet nozzle is positioned proximate the intermediate transfer member and configured for jetting ink droplets onto the sacrificial coating formed on the intermediate transfer member. An ink processing station is configured to at least partially dry the ink on the sacrificial coating formed on the intermediate transfer member. The printing apparatus comprises a substrate transfer mechanism for moving a substrate into contact with the intermediate transfer member.

主权项

1. An indirect printing process comprising:
providing an ink composition in an inkjet printing apparatus; forming a sacrificial wetting enhancement coating comprising polyurethane onto an intermediate transfer member, wherein forming the sacrificial wetting enhancement coating comprises applying a liquid coating material onto the intermediate transfer member and drying the coating material; ejecting droplets of ink in an imagewise pattern onto the sacrificial wetting enhancement coating after drying the coating material; at least partially drying the ink to form a substantially dry ink pattern on the intermediate transfer member, the substantially dry ink pattern comprises less than 5% water or solvent, based on the total weight of the dry ink; and transferring both the substantially dry ink pattern and the sacrificial wetting enhancement coating from the intermediate transfer member to a final substrate.