UV coating common faults and troubleshooting methods (11)

Eleven, UV light oil poor water resistance

1, the cause of the failure

1 UV light oil curing is not dry is the most important reason.

2 The ink on the surface of the printed matter does not dry, which affects the curing of the underlying layer of UV light energy. In particular, if the water-based ink does not dry well, the effect is even more severe.

3UV Varnish contains excessive amounts of hydrophilic non-reactive diluents such as ethanol. The photocuring process fails to evaporate completely and remains in the cured coating, affecting the water resistance.

2, elimination method

1 Before the coating, the surface ink of the printed matter must be fully dried, especially the water-based ink.

2 It is necessary to ensure that the UV varnish is fully cured, and check whether the light source is aging, whether the machine speed is too fast and whether ethanol is added too much, etc., and adjust in time.

3 If necessary, you can replace the UV varnish with fast curing speed and strong water resistance.