1, flow hanging: refers to the coating applied in the vertical plane, due to its poor resistance to flow hanging or improper application of paint film, film is too thick and other reasons to make wet paint film moving down, forming a variety of shapes under the edge of thick and uneven coating. Causes: ① the operation is not good, the nozzle gun is too big; ② paint is too thin; ③ The coating surface is too flat; ④ The coating is too thick, thin brush many times.
2, white: refers to the light coating drying process, paint film sometimes appears milky phenomenon. Causes: ① the moisture concentration is too high; ② solvent resolution is not enough; The moisture content of the substrate itself is too high.
3, wrinkling: refers to the film show how many regular small ripple wrinkles, it can be deep and some or all of the film thickness. Causes: ① The drying speed of primer and finish coat is inconsistent; ② The coating is too thick and the viscosity is too high; ③ The nozzle is not properly adjusted; ④PU coating curing agent added too much, drying speed is too fast.
4, orange peel: refers to the surface of the paint film showing the appearance of orange peel. Causes: ① leveling is not good; ② Low temperature; ③NC diluent is too much or not matching; ④ The base material is uneven or not well handled.
5. Bite bottom: refers to the same or different kinds of coating applied on the dry paint film, during the coating or drying, the drying film under the softening, uplift or detachment from the substrate phenomenon. Causes: ① two kinds of incompatible primer and finish (usually high content of primer); (2) the bottom is not completely dry on the paint; ③ The primer coat is too thick.
6, pinhole: refers to the presence of a fine hole similar to a needle in the paint film. Cause: ① Stir evenly, there is air inside the coating; ② Oil pollution and water pollution; ③ the surface of the coating is not smooth; ④ Spray is too thick, the solvent is not volatile.
7. Foaming: refers to the air or solvent vapor or other gases formed in the coating process or concurrently some bubbles. Causes: ① the coating has moisture; The coating has moisture; ③ High air humidity; (4) the oil; ⑤ diluent and curing agent do not match; ⑥ Uneven stirring, uneven surface.
8, rough surface: cause: ① the construction environment is too dirty, not clean enough; (2) the fineness of the coating itself is not enough, the surface of the coating has stolen goods; ③ The coating is not enough.
9, cracking: refers to the appearance of discontinuous changes in the paint film. Causes: ① the coating is too thick, expired coating; The coating is too thick, the coating itself is high hardness, more brittle; ③ Too high content of accelerant; (4) The solid content of the finish is low, the resin itself has problems and the external environment.
10, skin: cause: ① the coating surface moisture is too high; ② without oil sealing treatment; ③ primer is not dry coat; (4) Two kinds of incompatible primer and topcoat.
11, running oil: cause: ① there is water or oil residue in the paint; ② coated with oil residue, wax; ③ The coating viscosity is too high or too low.
12, the bottom: cause: (1) cover low, excessive sand; The coating is too thin, spraying is not uniform, the bottom deep surface is shallow.
13, sandpaper pattern: the cause: (1) the sandpaper number is too large, not dry on the grinding; ② There is no grinding along the direction of wood grain.
14, coating sticky sandpaper: cause: (1) the coating is not dry, the coating is too thick, the promoter is less; (2) the solvent itself dissolving force is poor, the air humidity is high.
15, granulation: cause: ① dust is too much, or there are impurities; The coating has impurities, without filtering; ③ Stirring is not uniform, not fully mixed; ④ spraying is not standard; ⑤ diluent does not match, does not make the element agent dissolved.
16, yellowing: cause: ① ultraviolet direct; ② Environmental factors air humidity; ③ The temperature is too high and the reaction is excessive; (4) The coating itself has low yellowing resistance.
17, ghost: cause: ① spraying gun uneven; Spray amplitude is different; ③ Uneven mixing.
18, back to stick: dry non-sticky paint film surface and then appear sticky phenomenon. Causes: ① the quality of paint is too poor; ② the outside temperature is high and the humidity is high; (3) itself is not completely dry on the packaging processing; The curing component is too little, and the air is not circulated.
Post time: Nov-01-2022
