Process for the protection of an engraved roll or plate by coating an engraved surface with an interlayer and thereafter applying a wear-resistant layer to the interlayer by PVD

• US 5,252,360 A
• Filed: 07/10/1992
• Issued: 10/12/1993
• Est. Priority Date: 03/15/1990
• Status: Expired due to Fees

• Current Assignee: Alois Vester, Wolfgang Huttl
• Original Assignee: Alois Vester, Wolfgang Huttl
• Inventors: Vester, Alois, Huttl, Wolfgang
• Primary Examiner(s): Beck, Shrive
• Assistant Examiner(s): Utech, Benjamin L.
• Application Number:
  US07/911,694
• Time in Patent Office: 459 Days
• Field of Search: 427/255.2, 427/295, 427/319, 427/350, 427/374.1, 427/419.7, 427/427, 427/438, 427/443.1, 204/192.16, 205/184
• US Class Current: 427/249.17
• CPC Class Codes: B41N 3/003 of intaglio formes, e.g. application of a wear-resistant coating, such as chrome, on the already-engraved plate or cylinder; Preparing for reuse, e.g. removing of the Ballard shell; Correction of the engraving

Abstract

A process for the production of engraved rolls and plates for printing operations wherein there are applied to a base member of metal, after it has been engraved, at least two layers of a metal and, respectively, a metal compound for increasing the hardness and the corrosion protection in order to achieve surface hardness values of at least 2000 HV.

Claims

1. A process for the protection of engraved rolls and plates for flexographic printing, intaglio printing or coating, wherein the rolls or plates each comprise a base member of metal, having a surface whereupon a gravure is engraved mechanically, electromechanically, or by etching, in correspondence with an embossed pattern, and wherein thenprotective layers for increasing corrosion resistance of a metal or metal component or ceramic component are applied on the engraved surface of the base member in order to increase the wear resistance and corrosion resistance, characterized in that

a) a dense interlayer of a metal-containing component or ceramic-containing component having a thickness of about 10-15 μ

m and a hardness of at least 850 HV according to Vickers hardness is applied to the surface of the base member provided with the gravure;

thereby reproducing the engraved gravure of the surface of the base member to a surface of the interlayer

b) thereafter the surface of the interlayer applied on the engraved surface of the base member is polished and cleaned,

c) thereafter the engraved base member equipped with the interlayer is subjected to vacuum and while being kept under vacuum the engraved base member is continuously heated up for tempering purposes to a temperature of at least 240°

C. to about 480°

C. and is subjected to this temperature for a time period of at least 1 hour up to about 4 hours,

d) then at the end of the tempering period while the tempered engraved base member equipped with the interlayer is continuously subjected to vacuum and is kept in a heated up condition of a temperature between 200° and

480°

C. there is applied to the surface of the interlayer applied on the surface of the base member provided with the gravure a wear-resistant layer of a metal compound having a hardness according to Vickers hardness of at least 2000 HV by physical vapor deposition in a thickness of about 4-8 μ

m, thereby reproducing the engraved gravure of the surface of the base member with applied interlayer to the surface of the vapor-deposited wear-resistent layer

e) then after removal of the vacuum, the surface of the vapor-deposited wear-resistant layer, is polished.

2. A process according to claim 1, characterized by producing, as the interlayer, an autocatalytically deposited nickel-phosphorus alloy with a phosphorus content of 5-13% by weight.

3. A process according to claim 1, characterized in that an interlayer of a silicon carbide is applied by spraying.

4. A process according to claim 1, characterized in that the interlayer is formed from a first coating, autocatalytically deposited onto the base member, of a nickel-phosphorus alloy with a phosphorus content of 3-13% by weight in a layer thickness of about 4-8 μ

m, and a second coating, deposited thereon electrolytically of chromium with a layer thickness of about 4-8 μ

m, whereby the summarized thickness of the thicknesses of the first and second coating is limited to about 10 to 15 μ

m.

5. A process according to claim 1, characterized by utilizing, for the wear-resistant layer, at least one of metallic borides, metallic carbides, metallic nitrides, metallic oxides, and metallic silicides wherein the metallic elements are selected from the group consisting of the elements of the fourth to sixth subgroups B of the Periodic Table.

6. A process according to claim 1, characterized by utilizing, for the wear-resistant layer, at least one of the metallic borides, metallic carbides, metallic nitrides and metallic oxides, wherein the metallic elements are selected from the group consisting of the elements of the fourth subgroup B of the Periodic Table.

7. A process according to claim 1, characterized by using titanium nitride for the wear-resistant layer.

8. A process according to claim 1, characterized by using titanium aluminum nitride or titanium aluminum carbonitride for the wear-resistant layer.

9. A process according to claim 1, characterized by using titanium carbonitride for the wear-resistant layer.

10. A process according to claim 1, characterized by using titanium carbide for the wear-resistant layer.

11. A process according to claim 1, characterized by utilizing, for the wear-resistant layer, at least one of metallic borides, metallic carbides, metallic nitrides, metallic oxides, and metallic silicides wherein the metallic elements are selected from the group consisting of titanium, zirconium, hafnium and vanadium.

12. A process according to claim 1, characterized by utilizing, for the wear-resistant layer, at least one of metallic borides, metallic carbides, metallic nitrides, metallic oxides, and metallic silicides wherein the metallic elements are selected from the group consisting of niobium, tantalum and chromium.

13. A process according to claim 1, characterized by utilizing, for the wear-resistant layer, at least one of metallic borides, metallic carbides, metallic nitrides, metallic oxides, and metallic silicides wherein the metallic elements are selected from the group consisting of molybdenum and tungsten.