Method for producing high gloss printed images
A method for printing an image on a surface of a substrate having a surface finish defined by a gloss, the method comprising: printing an image on the surface of the substrate, such that image areas thereof have a thickness, when fixed to the substrate and dry, of less than about 6 micrometers of a thermoplastic material; and smoothing the surface of at least a portion of the thermoplastic material.
1. A method for printing an image on a surface of a substrate having a surface finish defined by a gloss, the method comprising:
printing an image on the surface of the substrate, such that image areas thereof have a thickness, when fixed to the substrate and dry, of less than a surface roughness of the substrate and less than 6 micrometers, the image comprising a thermoplastic material; and
smoothing the surface of at least a portion of the thermoplastic material.
2. A method according to claim 1 wherein printed portions of the image have a thickness of less than about 4 micrometers.
3. A method according to claim 1 wherein printed portions of the image have a thickness of less than about 3 micrometers.
4. A method according to claim 1 wherein printed portions of the image have a thickness of less than about 2 micrometers.
5. A method according to claim 1 wherein printing the image comprises printing the image with a liquid toner comprising a colored thermoplastic material in a carrier liquid.
6. A method according to claim 5 wherein the thermoplastic material is colored with a pigment.
7. A method according to claim 6 wherein smoothing comprises;
heating the image to a temperature at which the thermoplastic material softens; and
passing the substrate through a nip formed by a smooth hard roller and another surface.
8. A method according to claim 6 , wherein the image is substantially free of carrier liquid during said smoothing.
9. A method according to claim 6 wherein smoothing comprises:
passing the substrate through a nip formed by a smooth hard roller, heated to a temperature at which the substrate softens, and another surface.
10. A method according to claim 6 , wherein the thickness of the printed areas of the image is such that only a portion of the surface of the outer surface of the thermoplastic material is situated above peaks of the roughness of the surface of the substrate.
11. A method according to claim 10 wherein the smoothing smoothes substantially only the portion of the surface of the thermoplastic material situated above the peaks.
12. A method according to claim 6 wherein the substrate is paper.
13. A method according to claim 6 wherein the thermoplastic material forms a film prior to the smoothing.
14. A method according to claim 1 wherein smoothing comprises;
heating the image to a temperature at which the thermoplastic material softens; and
passing the substrate through a nip formed by a smooth hard roller and another surface.
15. A method according to claim 1 , wherein the image is substantially free of carrier liquid during said smoothing.
16. A method according to claim 1 wherein smoothing comprises:
passing the substrate through a nip formed by a smooth hard roller, heated to a temperature at which the substrate softens, and another surface.
17. A method according to claim 1 , wherein the thickness of the printed areas of the image is such that only a portion of the surface of the outer surface of the thermoplastic material is situated above peaks of the roughness of the surface of the substrate.
18. A method according to claim 17 wherein the smoothing smoothes substantially only the portion of the surface of the thermoplastic material situated above the peaks.
19. A method according to claim 1 wherein the substrate is paper.
20. A method according to claim 1 wherein the thermoplastic material forms a film prior to the smoothing.
21. A method for printing an image on a surface of a substrate having a surface finish defined by a gloss, the method comprising:
printing an image on the surface of the substrate utiling a liquid toner comprising a colored thermoplastic material in a carrier liquid;
fixing the thermoplastic material to the surface of the substrate; and
smoothing the surface of at least a portion of the thermoplastic material.
22. A method according to claim 21 wherein the printed areas of the image form a layer of toner thinner than the roughness of the surface of the substrate.
23. A method according to claim 21 wherein the thermoplastic material is colored with a pigment.
24. A method according to claim 21 wherein smoothing comprises:
heating the image to a temperature at which the thermoplastic material softens; and
passing the substrate through a nip formed by a smooth hard roller and another surface.
25. A method according to claim 21 , wherein the image is substantially free of carrier liquid during said smoothing.
26. A method according to claim 21 wherein smoothing comprises:
passing the substrate through a nip formed by a smooth hard roller, heated to a temperature at which the substrate softens, and another surface.
27. A method according to claim 21 , wherein the thickness of the printed areas of the image is such that only a portion of the surface of the outer surface of the thermoplastic material is situated above peaks of the roughness of the surface of the substrate.
28. A method according to claim 27 wherein the smoothing smoothes substantially only the portion of the surface of the thermoplastic material situated above the peaks.
29. A method according to claim 21 wherein the substrate is paper.
30. A method according to claim 21 wherein the thermoplastic material forms a film prior to the smoothing.
31. A method for printing a substantially uniform gloss image on a substrate comprising:
printing an image on a surface of the substrate using pigmented liquid toner that forms a toner layer on regions of the surface on which it is printed; and
printing substantially regions of the surface of the substrate that are not printed with portions of the image, with a transparent toner that forms a layer on regions of the surface of the substrate on which the transparent toner is printed.
32. A method according to claim 31 wherein the transparent toner has substantially a same thickness as the pigmented toner.
33. A method according to claim 31 wherein the transparent toner is plastic at substantially the same temperature as the pigmented toner.
34. A method for printing a substantially uniform gloss image on a surface of a substrate using toner comprising:
applying a layer of thermoplastic material to the substrate surface that covers substantially the entire surface of the substrate, which layer is plastic at a temperature at which the toner is plastic;
printing the image on the thermoplastic layer using the toner; and
calendering the image at an image temperature at which both the image and thermoplastic layer are plastic.
35. A method according to claim 34 wherein applying a layer of thermoplastic comprises printing a layer of toner of a same type as the toner used to print the image.
36. A method of calendering an image printed on a substrate comprising:
providing a image comprising a thermoplastic colored material, fixed to a substrate and cooled to a temperature below a temperature at which the material is plastic;
heating the image to a temperature at which the material becomes plastic; and
passing the image through a nip between a smooth hard roller, at a temperature below that at which the material becomes plastic, and another surface against which the roller is pressed.
37. A method according to claim 36 and including:
continuing contact between the material to the roller after the substrate leaves the nip to allow the material to cool.
38. A method according to claim 36 wherein the material is cooled to a temperature at which it is not plastic prior to its removal from contact with the smooth hard roller.
39. A method according to claim 36 wherein the another surface is the surface of a hard roller.
40. A method according to claim 36 wherein the material comprises a thermoplastic toner material.