The products after A1odng treatment and drying are inspected. If defects such as scars are still found on the surface, they should be separated and separated; all inner surfaces, machined surfaces, threads, and thread holes that do not need to be painted are 100% protected. If the workpiece has secondary pollution during inspection and protection, it should be wiped with alcohol solvent to avoid affecting the adhesion of the coating film.
Check the type, name, model and variety of the paint used, then turn the paint bucket upside down and shake it for a certain period of time, then use a special tool to open the bucket, and use a clean stirring rod to effectively stir the original paint evenly. Transfer the original paint into different clean paint buckets, add a special release agent and stir repeatedly, and adjust to a suitable construction viscosity, and then filter it with a 160-200-day copper wire mesh.
The spraying process conditions are as follows.
Viscosity (with 4 cups of viscometer, 25°C)/s 18~20 Gun pressure/MPa 0.3~0.4
Spraying distance/mm 200~300 Spraying angle/degree 90
Spray gun caliber/mm 1.0~1.2
Wet-on-wet process can be used for spraying gray primer, aluminum powder paint, and varnish; before painting, the spray platform and Spray Gun should be cleaned, the ground should be kept clean, and the compressed air should be free of oil and water and kept stable; When aluminum powder is painted, it should be applied irregularly
Stir the industrial paint to avoid color difference between the products before and after processing; when painting, the principle of spraying the dead angle and non-observation surface first, and then the attention surface should be followed. When the color needs to be changed during the painting process, all paint supply systems should be cleaned Clean to avoid hue pollution and rough makeup; the surface of the painted parts should be evenly coated with a layer of coating film, and no bad phenomena such as missed spray, thin spray, sagging, blooming and rough makeup are allowed; If the coating is also sprayed on the installation part, it should be cleaned with a cotton cloth with solvent in the wet film state, but the coating film should not be damaged.
Whether it is a single coating film before entering the oven, or between wet-on-wet multi-layer coating film spraying, it should be dried for 5-15 minutes. One is to flatten the coating film, and the other is to release the solvent. During this process, air dust pollution should be avoided, the channel should be kept clean, and at the same time, it should not be touched by hands.
Temperature 140~160°C, time 30min.
During the drying process, the temperature should be controlled automatically, or the temperature change should be observed at any time, otherwise it is easy to cause poor curing or over-baking, which will make the coating film brittle and affect the adhesive force.
After the dried coating film is cooled naturally or forcedly, the hidden factory tools are removed for inspection.
Appearance of the coating film should have good gloss, high plumpness, no leakage, sagging, pinholes, blisters, shrinkage cavities, coarse makeup, yellowing and uneven color.
During the performance inspection, a certain number of products shall be selected on site for routine performance inspection, and the adhesion strength shall not be greater than level 1, the hardness shall not be less than 2H, and the resistance to 90 # gasoline for 24 hours shall be achieved.
Before packaging, the machined assembly surface should be leveled, and special containers should be used for repacking. At the same time, the products should be separated by special partitions. Depending on different requirements, the products should be packed in foam bags first and then put into special containers with partitions.
冯文;李正超;向旭东 - 《东方汽轮机》