Offset printing fluid - controlled by selective process to determine alcohol content

摘要

The appts. to establish and maintain the ratio of components in a fluid mixture uses a selective process to determine the alcohol content. The amount of wetting fluid required for offset printing is controlled during mixing and maintained in use. The alcohol is separated from the remainder of the fluid in an underpressure chamber (3) with an evaporation and overheating zone (A/B), and an electronically controlled heating system (4,4a). The dried alcohol vapour is measured (7) to give the alcohol content in vol%. The fluid is recirculated by an electronically controlled pump, and the fluid temp. is measured (8) where the alcohol content is dependent on temp. Removed alcohol is returned to the fluid by an ejector (6) to eliminate alcohol loss. The fluid pH is also measured at the temp. measurement stage (8). USE/ADVANTAGE - The mixture for offset printing is a mixture of water and alcohol at a given pH value and temp. The assembly gives a continuous monitoring and measurement which can be used by a computer to control the operation accordingly.