Method and apparatus for thermal treatment of printing surface in relief printing
AssigneeE. I. Du Pont de Nemours and Company
InventorsCarl Bernard Arnold, Gary W. Foggin
Life of this patent
Estimating the term…
Abstract
A heating step is performed in a printing operation where a gas jet emitting from a nozzle assembly impinges the exterior surface of a printing plate. The gas impingement provides rapid and specific convective heat flux to the exterior surface of the printing plate.
Claims34
A method for preparing a relief printing form from a photosensitive element having an exterior surface and comprising a layer of a photopolymerizable composition capable of being partially liquefied, comprising the steps of:
- (a) heating the exterior surface to a temperature sufficient to cause a portion of the layer to liquefy and form liquefied material;
- and
- (b) contacting the photosensitive element with a development medium to allow the liquefied material to be removed by the development medium;
- wherein the heating step is performed using a jet of heated fluid emitting from a nozzle assembly at a velocity of 10 to 35 meter/second and temperature of 110° C. to 350° C., and impinging the exterior surface at a heat flux greater than or equal to 10 kiloWatts/m2 (kW/m2) for a dwell time of less than 15 seconds.
An apparatus for preparing a relief printing form from a solid photosensitive element having an exterior surface and comprising a solid layer of a photopolymerizable composition, comprising:
- means for heating the exterior surface to a temperature sufficient to soften uncured portions of the solid layer;
- and
- means for contacting the photosensitive element with a development medium to allow the softened uncured portions to be removed by the development medium;
- wherein the means for heating comprises a jet of heated gas emitting from a nozzle assembly, wherein the nozzle assembly is configured to emit the jet of heated gas from the nozzle assembly at a velocity of 10 to 35 meter/second and temperature of 110° C. to 350° C., and have the gas jet impinge the exterior surface at a heat flux greater than 10 kWatts/m2 for a dwell time of less than 15 seconds, and further wherein the nozzle assembly is configured to cause the jet of heated gas to soften the uncured portions of the solid layer but not remove the uncured portions.
An apparatus for preparing a relief printing form from a solid photosensitive element having an exterior surface and comprising a solid layer of a photopolymerizable composition, comprising:
- means for heating the exterior surface to a temperature sufficient to soften uncured portions of the solid layer;
- and
- means for contacting the photosensitive element with a development medium to allow the softened uncured portions to be removed by the development medium;
- wherein the means for heating comprises a nozzle assembly configured to emit a jet of heated gas at a velocity of 10 to 35 meter/second and temperature of 110° C. to 350° C., and have the gas jet impinge the exterior surface at a heat flux greater than 10 kWatts/m2 for a dwell time of less than 15 seconds, and further wherein the nozzle assembly is configured to cause the jet of heated gas to soften the uncured portions of the solid layer but not remove the uncured portions.
Dependencies are inferred from the claim text.