Plate handling with thermal tensioning
View Patent ↗Printing plates are mounted onto a cylinder by first establishing a temperature difference between the plate and the cylinder; in particular, the temperature of the plate exceeds the temperature of the cylinder. The plate is then wrapped around the plate cylinder, and the temperature difference causes the plate to shrink against the cylinder.
1. A method of mounting a printing plate on a cylinder, the method comprising the steps of:
a. establishing a temperature difference between the plate and the cylinder, a temperature of the plate exceeding a temperature of the cylinder, wherein the plate is unmounted externally to the cylinder; and
b. wrapping the plate around the cylinder, the temperature difference causing the plate to shrink against the cylinder.
2. The method of claim 1 wherein the temperature difference is at least 3° C.
3. The method of claim 1 wherein the temperature difference is established by heating the plate.
4. The method of claim 3 wherein the plate is heated uniformly.
5. A method of mounting a printing plate on a cylinder, the method comprising the steps of:
a. establishing a temperature difference between the plate and the cylinder; temperature of the plate exceeding a temperature of the cylinder;
b. wrapping the plate around the cylinder, the temperature difference causing the plate to shrink against the cylinder, wherein the plate is drawn from a roll disposed within the interior of the cylinder and advanced around an exterior surface of the cylinder.
6. The method of claim 5 wherein the roll is heated.
7. The method of claim 5 wherein the exterior surface of the cylinder is cooled.
8. Apparatus for mounting a printing plate on a cylinder, the apparatus comprising:
a. means for establishing a temperature difference between the plate and the cylinder, wherein the plate is mounted externally to the cylinder and a temperature of the plate exceeds a temperature of the cylinder; and
b. means for facilitating wrapping the plate around the cylinder, the temperature difference causing the plate to shrink against the cylinder.
9. The apparatus of claim 8 wherein the facilitating means comprises registration pins and clamps.
10. The apparatus of claim 8 wherein the temperature difference is at least 3° C.
11. The apparatus of claim 8 wherein the means for establishing the temperature difference comprises means for heating the plate.
12. The apparatus of claim 11 wherein the heating means comprises a heated surface conforming substantially to the plate.
13. Apparatus for mounting a printing plate on a cylinder, the apparatus comprising:
a. means for establishing a temperature difference between the plate and the cylinder such that a temperature of the plate exceeds a temperature of the cylinder; and
b. means for facilitating wrapping the plate around the cylinder, the temperature difference causing the plate to shrink against the cylinder, wherein the plate is drawn from a roll disposed within the interior of the cylinder and advanced around an exterior surface of the cylinder, the facilitating means comprising:
(i) means, within the interior of the cylinder, for supporting the roll of plate material; and
(ii) means, within the interior of the cylinder, for receiving plate material extending over a travel path from the roll of plate material over the exterior surface of the cylinder.
14. The apparatus of claim 13 wherein the means for establishing a temperature difference comprises means for heating the roll.
15. The apparatus of claim 13 wherein the means for establishing a temperature difference comprises means for cooling at least the exterior surface of the cylinder.