tailieunhanh - Coatings of Polymers and Plastics part 15

Tham khảo tài liệu 'coatings of polymers and plastics part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Automotive Plastic Coatings in Europe 339 Table 8 Application Parameters for Waterbased Basecoats First spraying operation Metallic basecoats approximately 6-8 pm dry film thickness Air speed to m s Relative air humidity 60 - 5 Room temperature 23 - 3 C Intermediate flash-off Second spraying operation Approximately 2 min. @ 23 - 3 C Metallic approximately 6-8 pm dry film thickness Airspeed m s - m s Relative air humidity 60 - 5 Room temperature 23 - 3 C Air lock Final flash-off Approximately 3 to 5 min. Approximately 6 min. at 60 C drier rated for 80 C on work piece 2 - m s Cooling The substrate in the discharge lock of the blowing tunnel with fresh air to 30 C for the processing of waterborne paints. A case-to-case examination has to be made as to whether integration into existing painting lines is possible. However the paint supply system and the application technology must always be adapted. The most widely used pneumatic application process manual and or automatic processing is described in detail as an example. In general the parameters also apply to electrostatic processing. Further details are given in the next paragraph. The effect of the humidity see processing range is more crucial with waterborne basecoats than with conventional systems. Even after a 10-minute flash-off period there is still too much residual solvent in the paint film under Table 9 Pneumatic Spray Application Parameters Hand spray gun stainless steel Automatic Gun alternatively Nozzle 0 mm Air cap DeVilbiss Sprayer air pressure bar dynamic Material flow rate ml min. Object distance mm Booth temperature C Relative air humidity DeVilbiss JGV-563 St DeVilbiss AGMD ABB Behr 765 789 797 4-5 5-6 200-400 200-400 250-300 250-300 23 - 3 23 - 3 60 - 5 60 - 5 best spraying conditions Down draft m s - - Copyright Marcel Dekker Inc. All rights reserved. Marcel Dekker Inc. 270 Madison Avenue New York New York 10016 340 Gruner and Reinhart normal booth .