Summary of high pressure airless lame plating process

1. Surface pretreatment before painting

(1) Degreasing treatment, oil stains on the surface of the coated object (rust prevention oil, lubricating oil, cutting fluid, polishing agent, residues from magnetic particle inspection, etc.), need to use solvent or emulsion and lye for perfect degreasing treatment, The workpiece after degreasing is not allowed to be recontaminated.

(2) Rust and scale removal, the rust and scale on the surface of the workpiece can be removed by medium-effective chemical methods or mechanical methods.

(3) The conversion film formed on the surface of the workpiece after chemical treatment needs to be uniform and complete.

2. Surface preparation before painting (control and inspection)

(1) The clean surface after degreasing treatment (inspected by water film method) should be painted as soon as possible after passing the inspection (generally no more than 4~24h).

(2) The surface that has been pickled and derusted is not allowed to have residual acid and over-corrosion.

(3) The surface roughness after mechanical derusting must meet the requirements of the steel surface roughness grade before painting as required by the painting design.

(4) The cleanliness of the surface after mechanical derusting must meet the derusting level requirements of the steel surface before painting as required by the coating design, and dry and clean compressed air should be used to carefully remove the rust dust on the surface.

(5) The surface conversion coating after chemical treatment must meet the technical requirements for phosphating treatment of steel workpieces before coating in accordance with the coating design requirements.

(6) The surface of the workpiece to be painted should not have copper, tin; lead and other metal traces with higher potential than iron.

(7) The surface of the workpiece after anodization, oxidation and phosphating treatment should be painted within 24 hours. The cleaned surface after mechanical (spraying or projectile) treatment should be painted within 6 hours, and it is strictly forbidden to touch the corners with bare hands. Overdue unpainted surfaces should be re-treated.

(8) In order to meet the requirements of fine finishing coating, putty should be scraped on the surface with uneven defects that do not need to be coated, but the thickness should not exceed 3 times the thickness of the coating film.

(9) For surfaces that do not need to be painted (such as mating surfaces, friction surfaces, optical glass and rubber surfaces, etc.) or surfaces that must be covered due to color changes, they should be reliably tested with sheets, guards or tapes before painting. For protection, it is forbidden to use petroleum jelly and other oils.

3. Preparation of paint

(1) Before construction, check whether the paint variety meets the requirements of the paint design, and inspect it according to the technical conditions of the paint, and use it only after passing the test.

(2) Stir the paint in the container evenly before painting, adjust the paint to the construction viscosity with the specified supporting thinner, and then filter it with 120~160 mesh/cm2 copper wire cloth or other corresponding filter materials.

(3) For two-component coatings, first stir the base material evenly, then slowly add the curing agent to the base material, stir while adding, and after stirring evenly with a stirrer, the general reaction (also called aging or refinement) It should be used after more than 30 minutes. How much to use and how much to adjust according to the coating area. For the coating that has been added with curing agent, if it exceeds the specified period, it should be scrapped regardless of its appearance.

4. Construction environment conditions

(1) The temperature, humidity, and air cleanliness conditions at the construction site directly affect the quality of the coating. The temperature should generally be controlled at 10-30°C, the relative humidity should not exceed 75%, and the air cleanliness should be above grade two.

(2) If the painting is carried out in the painting room, it shall comply with the provisions of GB6514-1995 safety regulations for painting operations, painting process safety and its ventilation and purification.

(3) The compressed air used for painting needs to be filtered through the oil-moisture filter.

5. Spraying operation

(1) The Spray Gun should be as vertical and parallel as possible to the surface of the object to be coated.

(2) The distance between the Spray Gun and the surface of the object to be coated should be controlled at 200~400mm.

(3) The speed (also known as step frequency) of Spray Gun movement is 0.3~1.5m/s.

(4) 1/3 of the width of the sprayed surface should be overlapped, and the thickness of the coating should be as uniform as possible.

(5) The length of the paint delivery pipe from the high-pressure pump to the Spray Gun should be about 2 om, and the longest should not exceed 50 m.