TEST MEDIUM FOR ERIC ANALYSIS-THE EFFECT OF FURNISH

摘要

The amount of printing ink is most commonly estimated with the ERIC (Effective Residual Ink Concentration) measurement. This article discusses the effect of furnish on the feasibility of recently introduced low-grammage sheet preparation by the filter paper method. A comparison is made with traditional methods of preparing a low-grammage sheet on a wire screen and an opaque pad on filter paper. The more fine materials and printing ink a pulp suspension contains, the higher the difference in ERIC measured between test media prepared with and without filter paper. With deinked pulp this difference was seen as moderately low and the ERIC determination from a low grammage sheet prepared on a wire screen may suffice to provide the information needed for process control and other purposes. Care should be taken whenever sheets are prepared on a wire screen, however, because this results in an underestimation of the amount of small-sized ink capable of contaminating the process waters of papermaking processes.