Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/06—Lithographic printing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M1/00—Inking and printing with a printer's forme
  • B41M1/26—Printing on other surfaces than ordinary paper
  • B41M1/30—Printing on other surfaces than ordinary paper on organic plastics, horn or similar materials

Definitions

• the invention relates to a method for printing substrates in offset printing, after which a printing form is moistened and colored with a printing ink, then the printed image is transferred from the colored printing form to a blanket and from the blanket to the printing material.
• offset printing is a planographic printing process in which the printing and non-printing points of the printing form are practically in one plane.
• the printing form is prepared in such a way that the non-ink-carrying areas have water-holding and ink-repellent properties, while the ink-carrying areas, on the other hand, have ink-retaining and water-repellent properties.
• the non-printing areas of the printing plate are moistened by means of a dampening unit, while the printing ink is applied to the printing areas by means of an inking unit.
• the printed image of the inked printing form which can be a printing plate or a printing cylinder, is first transferred to a blanket cylinder.
• the actual printing on the printing material takes place, which is regularly a sheet of paper or plastic film to be printed.
• several offset printing units are arranged in series or battery-like one behind the other, so that each printing unit is responsible for printing one printing ink.
• the printing material is only printed once with each printing ink.
• this one-time printing is insufficient if a particularly high color saturation or a color-intensive printing result is required.
• This applies in particular to banners or transparent plastic films that are used in illuminated advertising. Plastic films of this type remain pale because, unlike paper, the color effect is significantly lower even with the same coating thickness applied. Now one could think of printing plastic film - this also applies in principle to other substrates - several times, i.e.
• the invention has for its object to provide a method of the type described above, according to which moisture-repellent substrates and in particular plastic films for illuminated advertising can be easily and quickly printed with high color saturation in offset printing.
• the invention in a generic method in that the rubber blanket is colored several times with the respective printing ink and thereby a printed image with an increased ink layer thickness is produced on the rubber blanket, so that the printed image is then transferred from the rubber blanket to the printing material in a single printing operation. and that before the transfer of the printing ink or the printed image with increased ink layer thickness onto the printing material, moisture or water present on the rubber blanket is removed and then a non-hygroscopic printing material is printed.
• blanket means any material which transfers the printing ink from the printing form to the printing material and which is suitable for the supersaturated absorption of printing ink.
• the rubber blanket that is used regularly can become oversaturated, so it has the property of actually absorbing the printing ink in the sense of multiple coloring.
• the rubber blanket is colored several times by repeatedly moistening and inking the printing form and after each ink application the blanket cylinder - the blanket is regularly clamped on a cylinder - absorbs the printing or color image from the inked printing form until the desired ink layer thickness application is achieved .
• the moisture (water) transferred to the blanket with the printing ink is removed according to the teaching of the invention. Only then is the print image with the corresponding high ink layer thickness transferred precisely and precisely in one-time printing to the non-hygroscopic substrate.
• the non-hygroscopic printing substrate printed according to the teaching of the invention is distinguished by special color intensity or high color saturation, which can be easily controlled by pressure. In any case, it can easily be determined by checking how often the rubber blanket has to be dyed and dehumidified or dewatered, for example whether double, triple, quadruple, etc. dyeing and dehumidification or dewatering of the blanket taking into account the respective color, moisture and desired color saturation is required. Once a standard is made, all sheets can be printed continuously. A color-intensive and sharp printed product is always created.
• the invention provides that the moisture or water is completely removed from the printing form on the rubber blanket immediately after the respective ink transfer.
• the invention recommends that the rubber blanket be blown on to remove moisture or water, e.g. is blown with warm air.
• the rubber blanket used for each printing ink is dyed and dehumidified or dewatered several times, and the individual printing inks are printed together in succession by one-time printing.
• the invention teaches the use of see-through foils as printing materials for producing luminous displays or color slides.
• the teaching of the invention even with see-through films or substrates made of transparent plastics, such as Rigid PVC can achieve an excellent color effect due to the increased paint layer thickness so that the color contrasts required for illuminated advertising are guaranteed.
• the increased ink layer thickness required for luminous transparencies can only be achieved by multiple transfer of the printing ink to the rubber blanket, especially taking into account today's highly pigmented printing inks. This in turn requires the removal of moisture or water from the rubber blanket when printing on non-hygroscopic materials such as see-through films made of plastic. In fact, the amount of ink is so high that the printed material can only be viewed in fluoroscopy.
• the method according to the invention is suitable both when using standard dampening systems and also from alcohol dampening systems.
• a blower series assigned to the rubber blanket or rubber cylinder ensures the necessary dehumidification or dewatering.
• the use of heat rays or similar heating devices is also conceivable as long as there is no longer any fear of the ink drying out prematurely.

Landscapes

• Printing Methods (AREA)
• Rotary Presses (AREA)

Applications Claiming Priority (2)

Publications (3)

Family

ID=6359654

Family Applications (1)

Country Status (4)

Families Citing this family (6)

Family Cites Families (11)

• 1989
  • 1989-07-06 AT AT89112330T patent/ATE120132T1/de not_active IP Right Cessation
  • 1989-07-06 EP EP89112330A patent/EP0352520B1/fr not_active Expired - Lifetime
  • 1989-07-26 JP JP1191591A patent/JPH0661998B2/ja not_active Expired - Lifetime
  • 1989-07-27 US US07/386,908 patent/US4960054A/en not_active Expired - Fee Related

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