1, causes bubble dry compound: ① roller takes too long to use or improper maintenance, will make the roller surface corrosion or damage, composite films by composite roller, corrosion or damage has not been pressing roller pressure and bubbles form. ② solvents with high content of active hydrogen, reaction releases carbon dioxide, forming bubbles. ③ coating below a certain limit, also easy to form bubbles. 2, dry compound bubble solution follows: replacement rollers, or repair. ② control solvent purity. ③ the coating rollers for cleaning or replacement coating rollers.