Common fault analysis of the most popular glazing

Analysis of common faults in glazing process

1. poor gloss

(1) fault phenomenon: the viscosity of varnish is small or the resin content in the system is small, and the varnish coating is thin; The substrate is rough and uneven, and the absorption of gloss is too strong; The wrinkle roller or gravure printing hole is thin, and 1. It is necessary to adjust the pointer of the experimental machine to the low zero position, the coating roller is not centered or flat, the supply of ink is insufficient, or the embossing roller is too heavy (too much pressure); Dilution solvent is diluted excessively or turbid with the wrong diluent; The ink film of packaging and printing is not dry; Gloss and ink repel each other or gloss foam is large, resulting in uneven finishing and blooming; The fluidity of glazing oil is poor, and the coating is uneven; High humidity and low temperature; Polish has impurities; Infrared or ultraviolet light source is aging, light

oil is not cured and dried thoroughly; Formula design of glazing oil system Eastman Chemical Company has developed a new generation of copolyester material, which is used in infant hearing echo detection equipment, or water molecules intrusion caused by the imbalance of light intensity and light energy, or there are gloss molecules that are not absorbed by photons, and there are also too short drying channels and too fast machine speed

(2) the solution is to appropriately increase the viscosity and concentration of the varnish, or increase the resin content, increase the coating amount or reduce the embossing to improve the thickness of the varnish; Choose a substrate with good surface flatness or low endoplasmic absorption; Replace the embossing roller again or have two automatic continuous production lines to make the gravure holes thick and deep to improve the transfer coating (printing) rate. Select the open-ended and flat coating roller and adjust the printing roller; Thinners or non reactive active thinners can be used less or added more frequently as far as possible, and thinners corresponding to the varnish system should be selected to maintain transparency after dilution; The polishing process is carried out after the graphic ink film of the packaged printing products is dry; Replace polish with ink that has good compatibility (mutual solubility), and polish without foam. You can also choose to polish after air printing or apply primer first and then polish; Choose the glazing oil with good fluidity (especially the one with small particle size) or add artificial smoothing agent into the glazing oil; Adjust the central air conditioner, control the humidity and temperature, or add slow drying plasticizing solvent to the varnish system; Replace the polish or filter the polish; Replace with a new infrared or ultraviolet light source, or turn it on again when the voltage is high, or increase the blowing cooling; Change the varnish with balanced volatility, or slow down the coating to extend the drying time, or turn on the machine when the light intensity meets the requirements (or adjust the voltage) in order to achieve full drying. ZTE Nubia Z5 also has a special titanium alloy plate drying