Metallic paint (also known as metallic effect paint) is generally achieved by air spraying. This kind of coating film with metal decoration has been widely used in plastic casings of TV sets and plastic casings of radio cassette players.
Before painting, it is necessary to first understand the material of the base layer, carry out surface treatment accordingly, and select paint base materials and thinners with good adhesion. The following introduces the process of using polystyrene and ABS plastic as the base layer to coat metallic paint.
(1) Surface treatment.
The dust can be blown off with compressed air first, and then degreased with isopropanol. In the case of foamed materials, after degreasing, apply a layer of acrylic enamel as a barrier coating.
(2) Paint selection and preparation.
Commercially available plastic special aluminum powder paint can be sprayed after being properly diluted with a special thinner. It can also be used to mix acrylic varnish (for plastic) and aluminum powder at a ratio of 100:4.5~5, then filter with fine silk cloth to remove coarse particles that are not well dispersed, and spray after dilution. After the pin powder is mixed into the paint, it should be used up within three days, otherwise the metallic feeling will decrease.
(3) Spraying technical requirements.
Spray metallic paint, generally use a small-caliber Spray Gun of 1.3~1.5 mm, the pressure is 3~5 kgf/cm2, the viscosity of the paint is 11~15 seconds (coating -4 cups), and the thickness of the coating film is 15~20 microns. should. At the same time strictly control the cleanliness of the construction environment. The construction temperature is 15~25℃ and the relative humidity is 50%~75%. Excessive humidity in the rainy season will affect the adhesion of the coating film, so it is not suitable for construction.
(4) dry.
After spraying, let the part stand for about 2 minutes, and then bake it at 40°C for about 15 minutes to form a film.
