Grinding process common failure analysis - poor gloss

1. Poor gloss

(1) Failure phenomenon Viscosity of the varnish oil is small or the content of the resin in the system is small, and the varnish coating is thin; the substrate is rough and uneven, and the varnish absorption is too strong; the anilox roller or the gravure printing dot is fine and shallow. The coating roller is not centered or uneven, the supply of ink is insufficient or the embossing roller is too heavy (the pressure is too high); the dilution solvent is excessively diluted or turbid with the wrong diluent; the packaging printing and graphic ink film is not dry; the varnish and ink phase Repulsion or light oil foam, resulting in uneven finishing, flowering; poor fluidity of the coating, uneven coating; high humidity and low temperature; coating oil impurities; infrared or ultraviolet light source aging, light

The oil curing and drying are not complete; the formula of the coating oil system is designed to have volatilization or intrusion of water molecules caused by the imbalance of light intensity and light energy, or there are lacquer molecules that are not absorbed by photons, and the drying path is too short and the speed is too low. Too fast.

(2)Solution to properly increase the viscosity and concentration of varnish, or increase the content of resin, increase the coating amount or reduce the imprint to increase the thickness of varnish; choose a surface with good surface flatness or a small selection of endoplasmic absorptivity Material; re-exchange the anilox roller or re-grained and printed thick and deep, to improve the transfer (print) rate, use a smooth and smooth coating roller, adjust the pressure roller; diluent or non-reactive activity Diluent can be used less or less frequently, use the thinner corresponding to the varnish system, and strive to remain transparent after dilution; the graphic and ink film of the printed product to be packaged is dried and then the varnish process; the varnish is replaced Good compatibility with ink (mutually soluble), no foaming varnishes, optional air glazing and glazing or priming oil first; good fluidity (especially light oil particle size) Add a leveling agent to the coating or varnish; adjust the central air-conditioning, control the humidity, temperature, or add a slow-drying plasticizing solvent in the varnish system; replace the varnish or filter the varnish; replace the new infrared or UV light source, or turn it on again when the voltage is high, or increase the cooling of the blower; Delivery of the coating balanced, deceleration or coated extended drying time, or when the intensity of light energy to meet the requirements (also higher voltage) power, in order to achieve sufficiently dried.