The colours in the printing units are arbitrary, but preferably different from each other.
Paper quantity: approx. 50-70 sheets per unit.
Paper thickness: 115 g/m2 recommended. Paper that is too thin may stick to the offset blanket. This will cause paper jams and tears inside the machine, resulting in a long cleaning of the cylinders and possibly a new rubber.
Procedure:
Install the new blankets and underlay sheets. Turn the dampening unit off. Before printing it is necessary to turn on the pressure at idle speed on all units for 5-7 min. Then, using a torque wrench, re-tension the blankets with the torque spanner. Check the offset blanket clamping value for the machine under test in the table below.
Perform printing on a paper with 0.10-0.15 mm loosened pressure alternately on all units for 20-25 sheets. Take 1 or 2 sheets (depending on the press model) for inspection.
If there is a noticeable difference in image in some areas of the sheet, reinstall the blanket by turning it 180 degrees and repeat printing on this unit.
Evaluate the results obtained, set aside the control sheets marked with the date, model, press factory number and number of the printing unit. Take a photo of the results obtained for the future.
| Maximum format of the press, mm | Tension, Nm |
| B3 (350×500) | 30-35 |
| B2 (540×750) | 40-45 |
| B1 (720×1050) | 55-65 |
| A0 (1200×850) | 65-70 |
| B0 (1000×1600) | 65-70 |
| Printing Press Manufacturer And Model | Total thickness = calibraied sheets + blanket, mm | Blanket Tension, Nm |
| MAN Roland 200/ 300/ 500 | 2,30 | 40-45 |
| MAN Roland 700 | 3,25 | 50-55 |
| MAN Roland 800/ 900 | 3,25 | 65-70 |
| Heidelberg SM102/ CD102 | 3,25 | 65 |
| Heidelberg XL105/ XL106 | 3,25 | 65 |
| Heidelberg SM72/ SM74/ SX74 | 3,25 | 40-45 |
| Heidelberg CD74/ XL75 | 3,25 | 40-45 |
| Heidelberg GTO46/ GTO52 | 3,25 | 30-35 |
| Heidelberg SM52/ SX52 | 3,25 | 30-35 |
| KBA Rapida 74 | 3,20 | 40-45 |
| KBA Rapida 105/ Rapida 106 | 3,20 | 60-65 |
Test duration: 1 hour
Amount of paper: 200-300 sheets of full format, 130-150 g/m2
Requirements: New blankets and underlay sheets installed.
Blanket tensioning is performed with a torque wrench (tightening torque depending on the press model).
Print cylinders must be thoroughly cleaned of dried ink and other contaminants.
Plates are arbitrary.
© 2024 PressInspection™ All Rights Reserved.
When using the materials of the site it is obligatory to indicate the link of source and the authorship.
© 2024 PressInspection™ All Rights Reserved.
When using the materials of the site it is obligatory to indicate the link of source and the authorship.