Quantitative Measurement of Gravure Ink Transfer.

Many earlier investigations of gravure ink transfer were restricted in scope due to the volatility of gravure inks and the non-availability of suitable test equipment. The GRI Gravure Printability Tester allows test prints to be made at production speeds with volatile production inks. Atomic absorption spectrophotometric analysis provides the means to accurately determine the amount of ink that has been transferred to paper. Quantitative measurements have been made at Gravure Research Institute of gravure ink transfer with an ink containing iron blue pigment printed on newsprint and coated stock under production conditions on the TAPPI GRI Printability Tester. The procedure requires chemical digestion of the printed samples to reduce and separate iron (Fe) into an aqueous solution which is then measured on the atomic absorption spectrophotometer for iron content with reference to measured values of standard iron solutions. The measured results of printed samples are calculated for weight of ink printed in grams per square meter for each printed density. The anticipated benefits to gravure printers of this technique are: Optimization of ink use, estimation of ink consumption, improvement in the relation between the appearance of proof and production copies, and optimization of the system for analysis and measurement of ink mileage. This paper describes the procedure in detail and the results obtained.