Curing Differs from Conventional Drying
In compatible UV systems, radiation initiates a chemical reaction that converts reactive components into a cured film. Assessment therefore considers the curing system’s suitability for the formulation and application conditions, alongside surface appearance.
Review the UV Source and Line Speed
Check source type, varnish compatibility and the condition of lamps and reflectors according to equipment instructions. Increasing speed reduces exposure time when other conditions remain unchanged. A varnish used with conventional lamps should not automatically be assumed suitable for UV LED.
Check Film Application and Substrate
Applied film amount and uniformity, the substrate and underlying ink influence the result. Review the transfer system, such as a flexographic anilox or screen-printing mesh, alongside viscosity and the grade’s specified operating conditions.
Validate with Relevant Checks
Assess adhesion, rub resistance, appearance and subsequent cutting, creasing or gluing. Agree with the supplier on a suitable cure-assessment method. For food packaging, review the selected grade, use conditions and documentation; a low-migration designation alone does not approve the finished pack.