Abstract:
An intermediate transfer member (ITM) for use with a printing system, the ITM having (a) a support layer; and (b) a release layer having an ink reception surface and a second surface opposing the ink reception surface, the second surface attached to the support layer, the release layer formed of an addition-cured, hydrophobic silicone material, wherein the release surface of the release layer has relatively hydrophilic properties with respect to the addition-cured, hydrophobic silicone material.
Abstract:
An intermediate transfer member (ITM) for use with a printing system, the ITM having (a) a support layer; and (b) a release layer having an ink reception surface and a second surface opposing the ink reception surface, the second surface attached to the support layer, the release layer formed of an addition-cured, hydrophobic silicone material, wherein the release surface of the release layer has relatively hydrophilic properties with respect to the addition-cured, hydrophobic silicone material.
Abstract:
A flexible belt is disclosed for use in a printing system. The belt comprises an endless strip which, in use, travels along a continuous path. Formations are provided along the sides of the strip which are capable of engaging with lateral tracks to place the belt under lateral tension, the lateral tracks further serving to constrain the belt to follow the continuous path.
Abstract:
Ink formulations suitable for deposition upon the intermediate transfer member of an indirect printing system and for transfer therefrom to a substrate. The inks are aqueous inkjet inks comprising an organic polymeric resin and a colorant. Ink film constructions including a plurality of continuous ink films fixedly adhered to the printing substrate that can be obtained with these inks are also disclosed. The inks and the printed constructions are such that the ink films and the dried inks composing them have a first dynamic viscosity within a range of 106 cP to 5·107 cP at at least a first temperature within a first range of 60° C. to 87.5° C., and a second dynamic viscosity of at least 6·107 cP, for at least a second temperature within a second range of 50° C. to 55° C.
Abstract:
An ink film construction including: (a) a printing substrate; and (b) at least one ink film, fixedly adhered to a top surface of the printing substrate, the ink film having an upper film surface distal to the top surface of the substrate, wherein a surface concentration of nitrogen at the upper film surface exceeds a bulk concentration of nitrogen within the film, the bulk concentration measured at a depth of at least 30 nanometers below the upper film surface, and wherein a ratio of the surface concentration to the bulk concentration is at least 1.1 to 1.
Abstract:
A printing process is disclosed which comprises directing droplets of an ink onto an intermediate transfer member to form an ink image, the ink including an organic polymeric resin and a coloring agent in an aqueous carrier, and the transfer member having a hydrophobic outer surface so that each ink droplet in the ink image spreads on impinging upon the intermediate transfer member to form an ink film. The ink is dried while the ink image is being transported by the intermediate transfer member by evaporating the aqueous carrier from the ink image to leave a residue film of resin and coloring agent. The residue film is then transferred to a substrate. The chemical compositions of the ink and of the surface of the intermediate transfer member are selected such that attractive intermolecular forces between molecules in the outer skin of each droplet and on the surface of the intermediate transfer member counteract the tendency of the ink film produced by each droplet to bead under the action of the surface tension of the aqueous carrier, without causing each droplet to spread by wetting the surface of the intermediate transfer member.
Abstract:
There is provided a method for treating a hydrophobic release layer of an intermediate transfer member for use in a printing process in which a negatively charged aqueous inkjet ink including a polymeric resin and a colorant is jetted onto said layer, the claimed method comprising contacting the release layer, prior to jetting the ink, with an aqueous solution or dispersion of a positively charged polymeric chemical agent reducing the tendency of a jetted ink droplet to bead up on the intermediate transfer member. Other embodiments, such as hydrophobic release layers having such chemical agents disposed thereupon and printed ink images comprising the same, are also described.
Abstract:
A flexible belt is disclosed for use in a printing system. The belt comprises an endless strip which, in use, travels along a continuous path. Formations are provided along the sides of the strip which are capable of engaging with lateral tracks to place the belt under lateral tension, the lateral tracks further serving to constrain the belt to follow the continuous path.
Abstract:
An ink film construction including: (a) a first printing substrate selected from the group consisting of an uncoated fibrous printing substrate, a commodity coated fibrous printing substrate, and a plastic printing substrate; and (b) an ink dot set contained within a square geometric projection projecting on the first printing substrate, the ink dot set containing at least 10 distinct ink dots, fixedly adhered to a surface of the first printing substrate, all the ink dots within the square geometric projection being counted as individual members of the set, each of the ink dots containing at least one colorant dispersed in an organic polymeric resin, each of the dots having an average thickness of less than 2,000 nm, and a diameter of 5 to 300 micrometers; each ink dot of the ink dots having a generally convex shape in which a deviation from convexity, (DCdot), is defined by: DCdot=1−AA/CSA, AA being a calculated projected area of the dot, the area disposed generally parallel to the first fibrous printing substrate; and CSA being a surface area of a convex shape that minimally bounds a contour of the projected area; wherein a mean deviation from convexity (DCdotmean) of the ink dot set is at most 0.05.
Abstract:
Disclosed are intermediate transfer members useful in the art of printing having a release layer with an image transfer surface having protonatable functional groups apparent thereupon. Also disclosed are methods of making such intermediate transfer members.