Under normal circumstances, we can calculate how many photons per unit volume of UV-curable material are required to cure, and the photochemical reaction rate is almost no longer a matter of time.  However, the addition of polymerization inhibitors in UV oil or ink delayed the molecular polymerization time after photochemical reaction (curing time) is directly related to the photoinitiator and polymerization inhibitors.  General UV varnish or ink formula curing time is selected within 0.1-0.2s.  However, the specific time is related to the following factors from the process after the formulation is determined:

1.UV intensity.  High strength leads to short curing time, and vice versa.  

2.Add solvent.  Adding diluents, such as ethanol, to UV varnish can reduce curing speed. 

3.Ambient temperature.  Coating temperature in 50-70 degrees is the ideal ambient temperature. 

4.Coating thickness, coating surface curing fast, but the surface is highly UV absorbent after curing, then UV intensity declines exponentially, reduce curing speed.  Therefore, the coating is thin and fast curing, and vice versa.