Colour stability of navigation buoy

In by solarsimulator-admin

Product Name: Navigation buoy D400, D800, green, red, yellow, black
Test Method: Solar and uv radiation, humidity and saltspray
Client: SeaHow by Meritaito Oy
Test Result:

The black, red, green and yellow colours of the navigation buoys remained in chromaticity regions according to IALA Recommendation E-108 – Surface colours used as visual signals on aids to navigation, Edition 3, 2013.

You will find the presentation here (Youtube 1:35).

The visual appearance of the colours was however changed due to changes in gloss and/or lightness of the colour that are not taken into account in the IALA Recommendation for chromaticity regions.

Test Purpose:

The test specimens, plastic material samples of navigation buoys, in colours black, red, green and yellow, were exposed to solar radiation until an UV-energy dose, which corresponds to at least 23 years in natural conditions on vertical surfaces, was reached.

Test Method in Detail:

The exposure in this test consists of two parts.

Exposure 1

Solar radiation exposure (UV+vis+IR)

Intensity of radiation: 1120 W/m2

T(Amb): ~40℃

Cycle: 22 h solar irradiation / 2 h water spray or high RH (salt mist spray weekly)

Duration: 56 days

Test conditions based on ISO 4892-1 and MIL-STD-810G METHOD 505.5

Exposure 2

High-intensity solar radiation exposure (UV+Vis+IR)

Intensity of radiation: Continuous high-intensity radiation (3500 W/m2 with sample cooling)

T(Amb): ~30℃

Duration: until reaching an UV-energy dose that corresponds to at least of 15 years in natural conditions on vertical surfaces


Chromaticity coordinate zone analysis

Colour CIELAB1976 and DE (colour change)