Studying On The Printability Of Offset Fluorescent Anti-Counterfeit Ink

The anti-counterfeit technology has developed rapidly in recent years, the colorless fluorescent anti-counterfeit ink has been used in anti-counterfeit printing technology greatly.The purpose is studying the printability of fluorescent ink,improving the color gamut of offset ink by adding fluorescent ink,mending the formula of fluorescent ink,guiding fluorescent ink using,improving anti-counterfeit effect and the quality of images.The flowing character of fluorescent ink was studied according to the rheology theory;The changing of color gamut by fluorescent ink was studied according to the printing chromatology theory;The data were handled with the least squares and nonlinear regression method;The verifying of the models' precision was according to correlation coefiicient.The rate of shear and shearing stress were measured by viscosimeter.And the curves of the rate of shear and shearing stess,the rate of shear and apparent viscosity were obtained,and the models between them were established.The coefficients of the models were obtained by experiments.Describing the rate of shear and apparent viscosity by the Oldroyd model,and comparing with the former model ;The model of shearing stress and time was established of thixotropy fluid;By two methods:adding fluorescent ink to offset ink and offset ink superimposed fluorescent ink could both improving the color gamut.It has indicated:The relationship between the rate of shear and shearing stress is conic.The fluorescent ink is a kind of plasticity fluid;The relationship between the rate of shear and apparent viscosity is power function.The fluorescent ink has the character which is the apparent viscosity reduce when the rate of shear increase;The Oldroyd model could describe apparent viscosity reduce by shear rate increasing;The relationship between shearing stress and time is sine when the rate of shear is confirmed;The fluorescent ink could heighten the brilliance of image and enlarge the color gamut in corresponding areas.