After coating dry back to white light loss or produce light phenomenon known as the white spots.
Is mainly due to the construction environment humidity is too big,
Relative humidity & gt;
And solvent volatilization too fast and make the coating surface temperature fell sharply, causing the water vapor agglutination in the film, so that the resin or cellulose ester precipitate, white phenomenon generally quick dry volatile coating (
Thermoplastic acrylic, etc. )
Due to contain a large number of low boiling point solvent and thinner, so prone to white phenomenon.
If slow joined moistureproof agent and a moderate amount of high boiling point volatile solvent to adjust the solvent formula, or to improve the construction environment, remove the moisture in compressed air and discharge of oil and water separator of air compressor and regularly, etc all can prevent white phenomenon.
Be coated surface temperature is too low, the plastic workpiece heated to a temperature higher than the environment temperature is 10 ℃ can also be less white phenomenon.