Re: Single diameter imp. cylinder of SM52 vs. double diameter imp. cylinder
If you look at all press manufacturers in the 28 inch (74cm) and larger formats, everyone uses double diameter impression and transfer cylinders even Heidelberg. In the smaller format presses with sheet sizes 14 x 20 inches (52cm) and smaller, Ryobi has been a longtime leader of using a double diameter impression cylinder for impression and transfer cylinders because of the flatter paper path which significantly reduces the chances of marking, allows the use of thicker stocks and fewer gripper changes which reduces the changes of register issues like slurring and doubling. On a Ryobi 524 series multicolor, there are only 4 gripper changes during four color printing sequence compared to at least 12 gripper changes on the Heidelberg GTO-V or SM 52-4. At Drupa this year, I would bet that you will see Heidelberg introduce double diameter impression and transfer cylinders on their SM 52 series.