Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
  • C22F1/047—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with magnesium as the next major constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/04—Printing plates or foils; Materials therefor metallic
  • B41N1/08—Printing plates or foils; Materials therefor metallic for lithographic printing
  • B41N1/083—Printing plates or foils; Materials therefor metallic for lithographic printing made of aluminium or aluminium alloys or having such surface layers
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon

Definitions

• the invention relates to an aluminum offset strip with a predominantly globulitically recrystallized and subsequently cold-deformed structure.
• Rolled strips and sheets made of aluminum or aluminum alloys are used in the thickness range from 0.1 to 0.5 mm to produce offset printing plates.
• the aluminum strip is provided with a light-sensitive photo layer, which is transformed by the action of light in such a way that it is insoluble for the developers used.
• a light-sensitive photo layer which is transformed by the action of light in such a way that it is insoluble for the developers used.
• an uncoated aluminum surface is present in the unexposed areas, which has hydrophilic properties.
• the fully developed printing plate is clamped on a plate cylinder for the printing process.
• An important requirement for offset printing plates is to have sufficient strength and resistance to cracking under this mechanical stress.
• the rolled surface must be roughened mechanically or electrochemically or chemically to better anchor the photosensitive layer.
• this roughening should be as homogeneous and fine-celled as possible.
• the object of the present invention is to further improve the strength and elongation values, in particular the thermal stability and rigidity, in the case of an offset tape of the type mentioned at the outset, the suitability of the surface for the subsequent electrochemical roughening being retained and a simplified method for producing such offset tapes to provide.
• the invention therefore aims at an Al offset tape with a predominantly globulitically recrystallized and then cold-deformed structure with a clearly fine grain structure and a strongly consolidated core area at the same time.
• the structure chosen means that the requirements for an offset tape can be met in an optimal manner without plating. Due to the significantly less steered rolling structure of the surface layer, mechanical and electrochemical roughening of the printing plate is possible, which has a homogeneous and fine-grained structure on the surface to be coated. The streaked rolled structure in the core ensures the necessary strength even after a possible thermal aftertreatment.
• the hot rolling process is controlled according to the invention in such a way that recrystallization cannot take place over the entire cross section of the offset strip, but only in the edge zones. This results in a non-recrystallized core zone with a streaked roll structure, which is important for the increased mechanical properties. Numerous tests have shown that a surface area of 10 to 30% - preferably 15% - with a globular structure is sufficient for the electrochemical roughening.
• the globular grain structure of the hot strip is lengthened by the subsequent cold rolling, but has a significantly lower stretching of the edge zone compared to the core.
• the grains elongated in the rolling direction have an elongation of s less than 8 on the surface, the core zone elongation values of s greater than 16.
• the evaluation method of R. Dederichs and H. Kostron two new rapid methods for grain cross-section determination, 1950, Verlag Chemie GMBH Weinheim / Bergstr, page 30-31 was used.
• the product according to the invention produced in this way shows an elongation S ⁇ 8 in the grain structure on the surface and an elongation S ⁇ 16 in the core zone.
• the comparison test shows that the method according to the invention leads to an offset tape which has the surface suitable for electrochemical roughening with very favorable mechanical properties.
• the mechanical properties can be improved to such an extent that the decrease in strength that would otherwise be expected after a thermal treatment of more than 200 ° C. is only delayed and occurs to a much lesser extent.
• the yield point ratio is a measure of the stiffness of the belt. The stiffness must be sufficiently high for good handling, in particular of thin strips.
• the offset tape produced according to the invention is therefore superior to the material hitherto used for these purposes, which does not have sufficient rigidity after the stoving temperature frequently used for offset purposes.

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Physics & Mathematics (AREA)
• Printing Plates And Materials Therefor (AREA)
• Metal Rolling (AREA)
• Laminated Bodies (AREA)
• ing And Chemical Polishing (AREA)
• Powder Metallurgy (AREA)
• Insulated Metal Substrates For Printed Circuits (AREA)
• Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
• Clamps And Clips (AREA)
• Manufacturing Of Printed Wiring (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6264006

Family Applications (1)

Country Status (6)

Families Citing this family (21)

Family Cites Families (10)

• 1985
  • 1985-03-02 DE DE19853507402 patent/DE3507402A1/de active Granted
  • 1985-12-23 ES ES550328A patent/ES8705928A1/es not_active Expired
• 1986
  • 1986-01-16 AT AT86100479T patent/ATE65214T1/de not_active IP Right Cessation
  • 1986-01-16 EP EP86100479A patent/EP0193710B1/de not_active Expired - Lifetime
  • 1986-02-27 JP JP61040508A patent/JPS61201747A/ja active Granted
  • 1986-03-03 US US06/835,559 patent/US4715903A/en not_active Expired - Lifetime

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