QUALICOAT Requirement for Natural weathering test

Exposure in Florida according to ISO 2810 , The natural weathering test should start in April.

Class 1 organic coatings

Samples shall be exposed facing 5° south to the horizontal and facing toward the equator for 1 year.
4 test panels per colour shade are required (3 for weathering and 1 reference panel)

Class 2 organic coatings

Samples shall be exposed facing 5° south for 3 years with an annual evaluation.
10 test panels per colour shade are required (3 per year for weathering and 1 reference panel).

Class 3 organic coatings

Samples shall be exposed facing 45° south for 10 years.
All the test panels shall be cleaned and measured annually by the laboratory in Florida.
After 1, 4 and 7 years, 3 test panels will be sent back to the QUALICOAT laboratory in charge for evaluation. The remaining 3 test panels will finally be sent back to the laboratory in charge at the end of the 10-year exposure period.

For all organic coatings:

Dimensions of the test panels: approx. 100 x 305 x 0.8 – 1 mm

After exposure, the exposed panels shall be cleaned using the following method:

Immersion in demineralised water with a 1% surface-active agent for 24 hours, then cleaned by wiping with a soft sponge with tap water applying gentle pressure, or using any other method approved by the Technical Committee. This process shall not scratch the surface.

The gloss shall be measured according to EN ISO 2813, at an angle of 60°.

The average is taken from the colorimetric measurements. The conditions for measurement and colorimetric evaluation are:

Colour variation: ΔE CIELAB formula according to ISO 7724/3, measurement including specular reflection.

The colorimetric evaluation shall be made for the standard illuminant D65 and the ten-degree normal observer.

To determine the gloss and colour, three measurements will be made on the cleaned panels before and after the weathering test. These measurements shall be made at different points at least 50 mm apart.

REQUIREMENTS:

Gloss

The residual gloss shall be at least 50% of the original gloss for class 1 organic coatings.
The following values apply to class 2 organic coatings:

  • After 1 year in Florida : at least 75%
  • After 2 years in Florida : at least 65%
  • After 3 years in Florida : at least 50%

The following values apply to class 3 organic coatings:

  • After 1 year in Florida : at least 90%
  • After 4 years in Florida : at least 70%
  • After 7 years in Florida : at least 55%
  • After 10 years in Florida : at least 50%

An additional visual assessment will be carried out for

  • organic coatings with an original gloss value of less than 20 units;
  • organic coatings with structured appearance in all gloss categories;
  • organic coatings with a metallic or metallised effect.

Colour change

For class 1 organic coatings the ΔE values shall not exceed the maximum values prescribed in the annexed table.
The following values apply to class 2 organic coatings:

  • After 1 year in Florida: not greater than 65% of the limits prescribed in the table
  • After 2 years in Florida: not greater than 75% of the limits prescribed in the table
  • After 3 years in Florida: within the limits prescribed in the table

For class 3 organic coatings, the ΔE value after 10 years in Florida shall not exceed the limits prescribed in the table.