Waterborne glazing common faults and troubleshooting methods

Waterborne glazing common faults and troubleshooting methods

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 Waterborne glazing common faults and troubleshooting methods

     First, the gloss is not good, the brightness is not enough

     1, the cause of the failure

     1 The paper is too thick and the osmotic absorption is too strong;

     2 the coating amount is insufficient and the coating is too thin;

     3 varnish has small viscosity and insufficient solid content;

     4 the surface of the printed matter is not dry;

     5 coating environment temperature is low, humidity is large;

     6 varnish inherent quality is not good.

     2, the elimination method

     1 Appropriately increase the viscosity of the varnish;

     2 increase the amount of coating;

     3 The ink should be sufficiently dried before glazing;

     4 The paper quality is too thick, and a primer should be applied first;

     5 increase the ambient temperature and drying temperature;

     6 Replace the glossy water-based varnish;

     7 A small amount of leveling aid can be added.

     Second, dry is not good, the surface is sticky

     1, the cause of the failure

     1 water-based varnish coating is too thick;

     2 varnish viscosity is high;

     3 drying tunnel temperature and hot air shortage;

     4 varnish PH value is too high;

     5 coating pressure is uneven, partial coating is too thick;

     6 The machine speed is too fast, especially when the printing carrier is a non-absorbent surface.

     2, the elimination method

     1 adjust to reduce the viscosity of the varnish, the diluent is a mixture of ethanol and water 1:1;

     2 appropriately reduce the amount of coating;

     3 adjust the pressure to make the coating uniform;

     4 to strengthen the drying tunnel temperature and hot air;

     5 PH oil value should generally be controlled at 8 ~ 9;

     6 adjust the speed according to the product;

     7 can add a quick-drying emulsion in an appropriate amount;

     8 Replace with quick-drying water-based varnish.

  Third, uneven surface coating, streaks and orange peel

     1, the cause of the failure

     1 varnish viscosity is excessive;

     2 the amount of varnish coating is too large;

     3 coating pressure adjustment is not suitable;

     4 The surface of the coating roller is too rough and not smooth;

     5 varnish drying too fast;

     6 varnish has poor leveling;

     7 ink does not dry, repels varnish.

     2, the elimination method

     1 The ink should be fully dried and dust removed before glazing;

     2 Adjust the coating pressure to make the coating uniform;

     3 The coating roller is rough, aged or deformed and should be reground or reworked;

     4 appropriately reduce the viscosity of the varnish;

     5 appropriate reduction of coating amount;

     6 Add a small amount of slow drying aid or PH stabilizer.

     Fourth, the glazing process has more bubbles

     1, the cause of the failure

     1 varnish viscosity is high;

     2 varnish PH value is low;

     3 cycles of excessive agitation;

     4 The amount of varnish in the rubber plate and the plastic barrel is insufficient;

     5 machine speed is too fast.

     2, the elimination method

     1 reduce the varnish viscosity;

     2 add appropriate amount of PH stabilizer to increase the PH value;

     3 appropriate amount of aqueous defoamer, to be fully mixed, and the maximum amount should not exceed 1%;

     4 increase the amount of varnish supply;

     5 Appropriately reduce the coating speed.

     Fifth, varnish cleaning is difficult, easy to crust

     1, the cause of the failure

     1 water-based varnish drying too fast;

     2 varnish PH value is low;

     3 varnish is poor in water solubility;

     4The downtime is long and it is not cleaned in time;

     5 The ambient temperature is too high.

     2, the elimination method

     1 Add a slow drying agent to reduce the drying speed;

     2 adding PH stabilizer to increase the pH value and improve the water solubility of the aqueous varnish;

     3 should be cleaned in time;

     4 Temporary shutdown, varnish system should continue to operate;

     5 When cleaning is difficult, use a water cleaner or ethanol for cleaning.