The change of printouts' quality depending on pressure of a blanket cylinder against an impression cylinder and a plate cylinder in offset machine

• Autorzy: Jurkiewicz A. , Pyryev Y.
• Języki publikacji: EN

Abstrakty

EN

According to lots of books, the pressure in offset printing affects the optical density and the quality of printouts. One of the quali-ty parameters is a tone value increase. An advantage of our research method is obtaining printing effects for different pressures on one printout, thus meaning for identical printing conditions. We obtained the same printing conditions through using different amounts of under-lay sheets fixed to the blanket cylinder, under a blanket. The pressure was increased from optimal settings – in accordance with the ma-chine manufacturer’s recommendation. The test printouts were printed using Adast Dominant 515, on a coated and an uncoated paper. The optical density value was measured on the tone value scale from 10% to 100% stepping regularly by 10%. For this scale the tone val-ue increase was computed. The research shows that for both types of paper the optical density and the tone value increase changes not very much above the optimal pressure recommended by the machine manufacturer. A difference in the optical density and in the tone val-ue increase is bigger for coated paper than for uncoated paper. Changes in these two parameters are negligible in places where used form 0 to 4 underlay sheets and are quite significant in the place where 5 underlay sheets were.

Słowa kluczowe

EN

optical density; tone value increase; contact between cylinders

PL

gęstość optyczna; cylinder; maszyna offsetowa

• Wydawca: Oficyna Wydawnicza Politechniki Białostockiej
• Czasopismo: Acta Mechanica et Automatica
• Rocznik: 2014
• Tom: Vol. 8, no. 1
• Strony: 9--15
• Opis fizyczny: Bibliogr. 11 poz., rys., tab., wykr.

Twórcy

autor

Jurkiewicz A.

• Faculty of Production Engineering, Institute of Mechanics and Printing, Warsaw University of Technology, ul. Konwiktorska 2, 00-217 Warsaw, Poland

autor

Pyryev Y.

• Faculty of Production Engineering, Institute of Mechanics and Printing, Warsaw University of Technology, ul. Konwiktorska 2, 00-217 Warsaw, Poland

Bibliografia

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• 3. ISO Standard 12647-1 (2004), Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 1: Parameters and measurement methods, Switzerland.
• 4. ISO Standard 12647-2 (2004), Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 2: Offset processes, Switzerland.
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