Drucktuch für Offset-Druck-Anwendungen

摘要

An offset printing blanket is used in the reproduction of surface structures liable to damage under cylinder pressure. The blanket has a base layer (1) in contact with the print cylinder, an intermediate compressible layer (2) incorporating fine gas pores (5), and an outer layer (3) in contact with the print web. Under compression during the print run the compressible (2) and contact layers (3) spread to cover and effect uniform pressure on the print web surface. The compressible layer has closed pores. Under a calibration pressure of 1350 kPa the compressible layer reduces in thickness by 20-50 per cent i.e. 0.45 to 0.9 mm. The printing blanket is pref. 2.5 to 3.0 mm thick. The compressible layer is 1-2 mm thick. The ratio of outer layer to intermediate layer thickness is in the range 1: 2.5 to 1:7. The outer layer has a Shore hardness of 55 ShA. The compensation layer (7) incorporates a fabric with stretch factor of more than 7 per cent under a load of 500N/5cm.