Landa Corporation Ltd.

Lasman, Marek

Peled, Hagai

Nakhmanovich, Gregory

Gregory Nakhmanovich

Benzion Landa

Sagi Abramovich

Galia Golodetz

Yehoshua Sheinman

Meir Soria

Mattetyahu Litvak

Alon Asher

Dan Avital

Snir Dor

Michal Gilady

Hagai Peled

Marek Lasman

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.

Digital printing process

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 10cP to 5·10cP 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 6·10cP, for at least a second temperature within a second range of 50° C. to 55° C.

Ink formulations and film constructions thereof

An ink film construction consisting: (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.

Ink film constructions

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 10cP to 5&#xb7;10cP at at least a first temperature within a first range of 60&#xb0; C. to 87.5&#xb0; C., and a second dynamic viscosity of at least 6&#xb7;10cP, for at least a second temperature within a second range of 50&#xb0; C. to 55&#xb0; C.

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.

A printing system and method are provided. The printing system includes an image forming station for temporarily deposit an image on an intermediate transfer member when the intermediate transfer member in the image forming station is in a first temperature range. The system further includes a drying station configured to increase a temperature of the intermediate transfer member from a first temperature in the first temperature range to a second temperature in a second temperature range, the second temperature being substantially higher than the first temperature. The system further includes an impression station configured to transfer the temporarily deposited image from the intermediate transfer member onto a substrate when the intermediate transfer member in the impression station is in the second temperature range. The system further includes a cooling station for retaining a coolant configured to revert the intermediate transfer member to a temperature in the first temperature.

A printing system is disclosed which includes a plurality of rollers configured to support and move a loop-shaped, flexible intermediate transfer member of at least 10 meters in length along a printing system path. The printing system further includes an image forming station configured to form an image on a portion of the intermediate transfer member, and an impression station configured to enable substantial transfer of the deposited image to a substrate. The printing system also includes at least one high-speed motor associated with the plurality of rollers and configured to move the loop-shaped flexible intermediate transfer member at a speed of at least about one meter per second. Moreover, the printing system includes guiding channels configured for exerting a lateral tensioning force on the loop-shaped intermediate transfer member as it is received within the guiding channels and circulates at the speed of at least about one meter per second.

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, (DC), is defined by: DC=1&#x2212;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 (DC) of the ink dot set is at most 0.05.

Aqueous inkjet ink formulations comprising a solvent including water and a co-solvent, a water soluble or water dispersible polymeric resin and a colorant, and a method for facilitating the use of such an aqueous inkjet ink in an indirect printing system in which the ink is jetted onto a hydrophobic release layer of an intermediate transfer member before having the solvent removed therefrom and being transferred to a substrate, wherein prior to the jetting of the ink the release layer is brought into contact with an aqueous solution of a positively charged polymeric chemical agent. Other aspects are also described.

Growing community of inventors

Rishon Lezion, Israel

Gregory Nakhmanovich