Fountain solution pH and conductivity changes caused by paper extractables during offset printing.

摘要

Economical and environmental issues are causing papermakers to change from the traditional acid papermaking process to neutral and alkaline papermaking processes. Also, offset printers are changing from traditional acid type fountain solutions, with or without alcohol, to: (a) neutral, (b) alkaline, and (c) acid with alcohol substitute type fountain solutions. The interaction between these new papermaking variables and fountain solutions and their effect on printability needs to be investigated.;The pH, conductivity, and contact angle changes of five different offset printing fountain solutions were monitored during offset printing press trials on acid, neutral and alkaline basestocks.;The results indicate that not enough contaminants were transferred into the fountain solutions from the basepapers to cause any printing problems.