# US 8,739,701 B2 · Method and apparatus for thermal processing of photosensitive printing elements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,701 B2 - Document ID: US8739701B2 - Status: Granted - Kind: B2 - Application number: 12/183,461 - Filed: 2008-07-31 - Published: 2010-02-04 - Granted: 2014-06-03 - Earliest claimed: 2008-07-31 - Applicants: Ryan Vest; Brian Cook; Jim Hennessy; David Elwell - Inventors: Ryan Vest; Brian Cook; Jim Hennessy; David Elwell - Web page: https://patentgrep.com/patent/US8739701B2 ## CPC - G03F 7/40: Treatment after imagewise removal, e.g. baking - G03F 7/36: Imagewise removal not covered by groups G03F7/30 - G03F7/34, e.g. using gas streams, using plasma - B41C 1/1075: {Mechanical aspects of on-press plate preparation (B41C1/1008 - B41C1/1066 take precedence)} - B41C 1/1083: {Mechanical aspects of off-press plate preparation (B41C1/1008 - B41C1/1066 take precedence)} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) - B41C: PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES (photomechanical processes for producing printing surfaces G03F; photoelectrical processes for producing printing surfaces G03G) ## Abstract The present invention pertains to a process and an apparatus for treating a photosensitive element to form a relief structure suitable for flexographic printing plate. The apparatus comprises an enclosure, a conveyor, a heatable roller with absorbent material conducted over it, and a roller that can significantly smooth or uniformly roughen the relief structure of the flexographic printing plate. Previously selectively cured photosensitive elements are developed by means of the heatable roller by blotting with the absorbent material, and the resulting relief structure is made uniform by way of a smoothing or roughening roller. The flexographic plates produced by the method and apparatus are especially suited to processes that require substantially smoothed or uniformly roughened printing plate surfaces, which are capable of producing better quality printing. ## Claims ### Claim 1 An apparatus for forming a relief structure on a flexographic photosensitive printing element, wherein the flexographic photosensitive printing element comprises a flexible substrate and at least one layer of photosensitive material comprising cured photosensitive material and uncured photosensitive material on the flexible substrate, the apparatus comprising: (i) an enclosure; (ii) conveying means comprising a continuous loop, upon which a flexographic photosensitive printing element can be supported; (iii) a mounted heatable roller in the enclosure; (iv) an absorbent material covering at least a portion of the heatable roller, wherein the absorbent material is capable of absorbing liquefied or softened uncured photosensitive material from the flexographic photosensitive printing element when the flexographic photosensitive printing element comes into contact with the absorbent material on a portion of the heatable roller; (v) a smoothing or roughening roller which changes the surface roughness of the cured photosensitive material of the flexographic photosensitive printing element when the smoothing or roughening roller comes into contact with the cured photosensitive material of the flexographic photosensitive printing element and wherein the smoothing or roughening roller is not in contact with any portion of the absorbent material at the point where such absorbent material comes into contact with the cured photosensitive material of the flexographic photosensitive printing element. ### Claim 2 (depends on 1) The apparatus according to claim 1 comprising additional heating means for heating the printing element. ### Claim 3 (depends on 1) The apparatus according to claim 1 further comprising means for continuously conveying the absorbent material over at least a portion of the heatable roller. ### Claim 4 (depends on 1) The apparatus according to claim 1 wherein the smoothing or roughening roller contacts the printing element before the printing element contacts the heatable roller. ### Claim 5 (depends on 1) The apparatus according to claim 1 wherein the smoothing or roughening roller contacts the printing element after the printing element contacts the heatable roller. ### Claim 6 (depends on 1) The apparatus according to claim 1 wherein the smoothing or roughening roller is heated. ### Claim 7 (depends on 6) The apparatus according to claim 6 wherein the smoothing or roughening roller is electrically heated. ### Claim 8 (depends on 1) The apparatus according to claim 1 wherein the smoothing or roughening roller is coated with a resilient surface. ### Claim 9 (depends on 8) The apparatus according to claim 8 wherein the resilient surface is comprised of rubber. ### Claim 10 (depends on 8) The apparatus according to claim 8 wherein the resilient surface is comprised of a fluorinated polymer. ### Claim 11 (depends on 8) The apparatus according to claim 8 wherein the resilient surface is comprised of a fluorinated polymer/rubber composite. ### Claim 12 (depends on 1) The apparatus according to claim 1 wherein the effect of the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 10-2000 nm. ### Claim 13 (depends on 1) The apparatus according to claim 1 wherein the effect of the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 100-1000 mm. ### Claim 14 (depends on 1) The apparatus according to claim 1 wherein the effect of the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 150-600 nm. ### Claim 15 (depends on 1) The apparatus according to claim 1 wherein the smoothing or roughening roller is driven by a motor. ### Claim 16 (depends on 1) The apparatus according to claim 1 wherein a pneumatic cylinder controls the position of the smoothing or roughening roller. ### Claim 17 A method of forming a relief structure on a flexographic photosensitive printing element, wherein the flexographic photosensitive printing element comprises a flexible substrate and at least one layer of photosensitive material comprising cured photosensitive material and uncured photosensitive material on the flexible substrate, the method comprising the steps of: (i) providing an enclosure; (ii) providing conveying means comprising a continuous loop, upon which the flexographic photosensitive printing element is supported by the conveying means with the flexible substrate in contact with the conveying means; (iii) providing a mounted heatable roller in the enclosure; (iv) providing an absorbent material to at least a portion of the heatable roller, wherein the absorbent material absorbs liquefied or softened uncured photosensitive material from the flexographic photosensitive printing element when the flexographic photosensitive printing element comes into contact with the absorbent material on a portion of the heatable roller; (v) causing the flexographic photosensitive printing element to come into contact with the absorbent material between the conveying means and the heatable roller; (vi) heating the heatable roller to a temperature that causes the uncured photosensitive material to liquefy or soften when contact between the heatable roller, the absorbent material and the flexographic photosensitive printing element is made; (vii) causing the same side of the flexographic photosensitive printing element that contacted the absorbent material to contact a smoothing or roughening roller that changes the surface roughness of the cured photosensitive material of the flexographic photosensitive printing element, wherein this contact does not occur at the point where the absorbent material contacts the flexographic photosensitive printing element. ### Claim 18 (depends on 17) The method according to claim 17 comprising providing further heating means to heat the printing element. ### Claim 19 (depends on 17) The method according to claim 17 further comprising the step of continuously conveying the absorbent material over at least a portion of the heatable roller. ### Claim 20 (depends on 17) The method according to claim 17 wherein contacting the smoothing or roughening roller occurs before the printing element contacts the heatable roller. ### Claim 21 (depends on 17) The method according to claim 17 wherein contacting the smoothing or roughening roller occurs after the printing element contacts the heatable roller. ### Claim 22 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller is heated. ### Claim 23 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller is coated with a resilient surface. ### Claim 24 (depends on 23) The method according to claim 23 wherein the resilient surface is comprised of rubber. ### Claim 25 (depends on 23) The method according to claim 23 wherein the resilient surface is comprised of fluorinated polymer. ### Claim 26 (depends on 23) The method according to claim 23 wherein the resilient surface is comprised of a fluorinated polymer/rubber composite. ### Claim 27 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 10-2000 nm. ### Claim 28 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 100-1000 nm. ### Claim 29 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 150-600 nm. ### Claim 30 (depends on 17) The method according to claim 17 wherein a pneumatic cylinder controls the position of the smoothing or roughening roller. ### Claim 31 (depends on 17) The method according to claim 17 wherein the smoothing or roughening roller is driven by a motor. ### Claim 32 A method of forming a relief structure on a flexographic photosensitive printing element, wherein the flexographic photosensitive printing element comprises cured photosensitive material and uncured photosensitive material on a flexible substrate, the method comprising the steps of: (i) providing an enclosure: (ii) providing conveying means comprising a continuous loop, upon which the flexographic photosensitive printing element is supported by the conveying means with the flexible substrate in contact with the conveying means; (iii) developing the flexographic photosensitive printing element to remove the uncured photosensitive material; (iv) conveying the developed flexographic photosensitive printing element on said conveying means such that the flexible substrate is in contact with the conveying means and the face of the photosensitive printing element opposite the flexible substrate comes into contact with at least one smoothing or roughening roller thereby changing the surface roughness of the cured photosensitive material of the photosensitive printing element, wherein said contact does not occur at a point where any absorbent material contacts the photosensitive printing element. ### Claim 33 (depends on 32) A method according to claim 32 wherein the at east one smoothing or roughening roller is heated. ### Claim 34 (depends on 32) The method according to claim 32 wherein the smoothing or roughening roller is coated with a resilient surface. ### Claim 35 (depends on 34) The method according to claim 34 wherein the resilient surface is comprised of rubber. ### Claim 36 (depends on 34) The method according to claim 34 wherein the resilient surface is comprised of fluorinated polymer. ### Claim 37 (depends on 34) The method according to claim 34 wherein the resilient surface is comprised of a fluorinated polymer/rubber composite. ### Claim 38 (depends on 32) The method according to claim 32 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 10-2000 nm. ### Claim 39 (depends on 32) The method according to claim 32 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 100-1000 nm. ### Claim 40 (depends on 32) The method according to claim 32 wherein the smoothing or roughening roller changes the arithmetical mean roughness of the surface of the printing element by 150-600 nm. ### Claim 41 (depends on 32) The method according to claim 32 wherein the smoothing or roughening roller is driven by a motor. ### Claim 42 (depends on 32) The method according to claim 32 wherein a pneumatic cylinder controls the position of the smoothing or roughening roller.