Study on Methods of Estimating Flexibility of UV Curable Varnish Film

The performance of UV curable varnish film has a great effect on the quality of package printing products,especially the flexibility.The existing methods of estimating the flexibility of film are inconsistent and most of these are qualitative assessment,and there has not a scientific system.A new method of estimating flexibility of film was put forward,which we named stress-strain curve method,with which we studied the flexibility of UV curable varnish film.The results indicated that UV curable varnish prepared of bifunctional monomers has the best flexibility;and UV curable varnish prepared of the prepolymer2491 has the best flexibility.