Claims
- 1. A process for producing a support for a lithographic printing plate, which comprises jetting a high-pressure liquid from at least one nozzle at a high rate, joining the jetted stream with a slurry containing a fine abrasive powder having a specific gravity of not less than 2.5 and having a sharp-angled tip having a radius of not more than 20 .mu.m, said slurry being spouted from at least one spout, directing the resulting mixed stream to strike against a surface of a metal sheet to carry out first graining, and modifying the first roughness thus formed on the metal sheet by brush graining to form a second roughness.
- 2. A process as in claim 1, wherein said process further includes at least one of chemical etching and electrochemical graining of the metal sheet after the brush graining.
- 3. A process as in claim 1, wherein the high-pressure liquid is jetted from at least one nozzle at a flow rate of from 30 to 140 m/sec at a pressure of from 5 to 100 Kg/cm.sup.2, and the slurry is spouted from a spout at a flow rate of from 2 to 25 m/sec.
- 4. A process as in claim 3, wherein the angle of the striking stream against the metal sheet is from 15.degree. to 165.degree..
- 5. A process as in claim 1, wherein the abrasive powder retains its sharp-angled form after striking the metal sheet.
- 6. A process as in claim 1, wherein the abrasive powder has a silicon content of 8% by weight or more.
- 7. A process as in claim 1, wherein the metal surface having the first and second roughness has an average centerline roughness of from about 0.3 to about 1.2 .mu.m.
- 8. A process as in claim 1, wherein the metal surface having the first and second roughness has an average centerline roughness of from 0.35 to 0.8 .mu.m.
- 9. A process as in claim 1, wherein the angle of the striking stream against the metal sheet is from 15.degree. to 165.degree..
- 10. A process as in claim 1, wherein said metal sheet is an aluminum sheet or an aluminum alloy sheet.
- 11. A process as in claim 1, further comprising anodic oxidation following brush graining.
Priority Claims (1)
Number |
Date |
Country |
Kind |
61-37323 |
Feb 1986 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 018,366 filed Feb. 24, 1987, and now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (7)
Number |
Date |
Country |
0131926 |
Jan 1985 |
EPX |
0213371 |
Mar 1987 |
EPX |
2742637 |
Apr 1979 |
DEX |
54-46136 |
Apr 1979 |
JPX |
54-30554 |
Oct 1979 |
JPX |
165625 |
Oct 1964 |
SUX |
625834 |
Jul 1949 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
18366 |
Feb 1987 |
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