Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
  • B41F23/04—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing by heat drying, by cooling, by applying powders
  • B41F23/0403—Drying webs
  • B41F23/0406—Drying webs by radiation
  • B41F23/0409—Ultraviolet dryers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
  • B41F23/04—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing by heat drying, by cooling, by applying powders
  • B41F23/0403—Drying webs
  • B41F23/0436—Drying webs using a combination of radiation, conduction or convection
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
  • B41F23/04—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing by heat drying, by cooling, by applying powders
  • B41F23/044—Drying sheets, e.g. between two printing stations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
  • B41F23/04—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing by heat drying, by cooling, by applying powders
  • B41F23/0486—Particular types of dryers

Definitions

• the invention relates to a sheet-fed offset press with electron beam curing for the polymerization of printing inks and coatings.
• Electron beam hardening is, in addition to UV curing, a well-known method for curing printing inks and coatings, which polymerize under the influence of energy.
• the advantage of electron beam curing is that it can be dispensed with photoinitiators.
• Another advantage of the electron beam curing is the complete hardening of the ink and coating film, so that no fragments and cleavage residues in the ink and coating film exist that migrate through the substrate as on the UV inks on the packaged or by Abklatschmigration in the delivery of the printing press can go to the following in the stack bow.
• Electron beam drying is therefore mainly used for the production of food packaging, even if modern UV printing inks and coatings have reached a high safety standard. Electron beam drying provides the best cure and, despite its high cost, is often used in food packaging printing. The electron beam drying is also "color blind", i. the curing of the ink film is not affected by the pigmentation of the ink as in the case of UV curing. Another advantage of electron beam drying is the better anchoring of the ink film on the substrate, since many radicals are formed by the electron beam drying, which improve the anchoring of the ink film on the polymeric substrate.
• a major disadvantage of electron beam drying is that they require an inert environment, which can be prepared, for example, by a nitrogen purge.
• the presence of oxygen leads to an inhibition of the polymerization and thus possibly insufficient curing.
• UV printing inks there is also an inhibition, but this can be stopped by the addition of amines and averted.
• this addition of amines does not lead to any success in electron beam drying, which therefore always requires an inert atmosphere in the prior art.
• the electron beam drying is usually installed at the end of the printing press, since the equipment is very expensive and at the same time suitable for curing several printing ink and varnish layers. Also, it is often desired to give the varnish which is applied in a varnishing unit a sufficient development time for a good development of gloss. This usually excludes an application in a sheet-fed printing machine, as due to the rotating gripper systems in the boom a sheet-fed press and the air turbulence, for example by sheet guiding elements only at very high cost and gas consumption an inert atmosphere can be created. Although some applications of electron beam drying in sheetfed machines have become known, these applications have prevailed only in web offset printing on a broad front, since an inert atmosphere can be created more easily here.
• the object of this invention is to enable electron beam drying in a sheet-fed offset printing machine without the need for a great deal of effort to create an inert atmosphere.
• electron beam drying is thus advantageously made possible by adding small amounts of photoinitiators to the printing inks and lacquers.
• the photoinitiators preferably achieve a surface hardening of the printing ink or coating films under UV radiation. This is followed by a first drying stage with UV curing an electron beam hardening, which ensures the complete and residue-free hardening.
• only the paint film may be provided with a photoinitiator if it covers the entire ink film (s).
• the advantage of the solution found lies in the fact that it is possible to substantially or completely dispense with the inhibition which can be realized in sheet-fed offset printing, but nevertheless the advantages of electron beam drying, namely the complete and secure curing of the printing ink and coating film, can be utilized. Due to the hardening of the surface with UV lamps, this becomes less permeable to atmospheric oxygen and the hardening reaction due to electron beam drying can proceed largely undisturbed. This process is not only limited to the surface hardening of the printing ink and varnish film, but the electron beam drying can also be used for post-curing completely UV-cured ink and varnish films.
• a further advantage of the chosen method is that the adhesion of the printing ink and lacquer films to a polymeric printing substrate can be improved by electron beam drying.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
• Printing Methods (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=38920941

Family Applications (1)

Country Status (2)

Cited By (2)

• 2006
  • 2006-08-15 DE DE200610038386 patent/DE102006038386A1/de not_active Withdrawn
• 2007
  • 2007-07-31 EP EP07014965A patent/EP1892097A2/fr not_active Withdrawn

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