Abstract

The invention relates to a printing method using a printing press, wherein a printing agent is transferred by means of a print image carrier onto a material to be printed, and wherein the printing agent and/or a fountain solution are indirectly or directly transferred to the print image carrier by means of transfer elements for the printing agent from a printing agent reservoir and/or by means of transfer elements for the fountain solution from a fountain solution reservoir, wherein the print image carrier and/or the transfer elements work against counter rolls thus forming a roller nip, or work against the material to be printed, thereby changing the relative position to said rolls, and wherein the print image carrier and/or the transfer element comprise a surface layer or a near-surface layer made of elastic or polymeric material. In order to prevent the formation of deposits on the print image carrier, according to the invention an elastic or polymeric material that is designed to be conductive with respect to electrostatic charges is used, among other things, as the cover layer or near-surface layer so as to decrease and/or reduce electrostatic charges on the print image carrier and/or at least one transfer element.

IPC Classes  ?

• B41F 13/193 - Transfer cylinders; Offset cylinders
• B41F 23/02 - Devices for treating the surfaces of sheets, webs or other articles in connection with printing by dampening
• B41F 30/04 - Devices for attaching coverings or make-ready devices; Guiding devices for coverings attaching to transfer cylinders
• B41N 1/12 - Printing plates or foils; Materials therefor non-metallic other than stone
• B41N 1/22 - Curved printing plates, especially cylinders made of other substances
• B41N 1/24 - Stencils; Stencil materials; Carriers therefor
• B41N 10/00 - Blankets or like coverings; Coverings for wipers for intaglio printing
• C09D 11/02 - Printing inks

Abstract

The invention relates to a printing method, in particular an offset-printing method, in which in the wet offset method a wetting agent is fed to an imaged printing plate by way of a wetting apparatus and a printing agent is fed to said plate by way of an inking apparatus, wherein partial areas of the imaged printing plate take up more wetting agent, and other partial areas of the imaged printing plate take up more printing agent in order to generate an image, or wherein in the dry offset method the imaged printing plate remains free of ink in areas using an elastomer coating, and wherein the printed image is transferred from the printing plate to a rubberized printed image transfer member and from there to the substrate to be printed. According to the invention, a separating means, preferably in an aqueous phase, is fed to the rubberized transfer member, wherein the separating means reduces the adhesiveness between the rubberized surface of the transfer member in the non-printing area and reduces printing agent accumulations on the transfer member that adhere strongly or at least partially loosens the printing agent accumulations that adhere strongly and at least partially suppresses the build-up thereof. The separating means can comprise one or more components selected from the group consisting of hydrophobic silicone oils, penetrating oils, C6-C30 alcohols, polyethers with more than 4 C atoms per ether groups on average, and esters.

IPC Classes  ?

• B41N 3/08 - Damping; Neutralising or similar differentiation treatments of lithographic printing formes

Abstract

The invention relates to the use of a roller or a rubber blanket with a covering made of elastomeric material with an outer surface for indirect or direct transfer of a damping solution and/or a printing agent to a print carrier of a printing press. In order to enable a virtually optimum printing result, even in the presence of changing process conditions, and to display improved back-transfer properties with unchanging properties over the service life, it is proposed that a roller/rubber blanket be used which has an outer surface that constitutes an elastomeric surface coating of the covering and contains, or completely consists of, a fluoroelastomer, particularly an elastomeric fluorinated rubber. The fluorinated rubber can, in particular, be a tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymer.

IPC Classes  ?

• B41F 13/10 - Forme cylinders