Standard Test Method for Color Stability of Building Construction Sealants as Determined by Laboratory Accelerated Weathering Procedures

Importancia y uso:

5.1 This test method is intended to induce color changes in sealants, as well as their constituent pigments, associated with end-use conditions, including the effects of sunlight, moisture, and heat. The exposures used in this test method are not intended to simulate the color change of a sealant caused by localized weathering phenomena, such as atmospheric pollution, biological attack, or saltwater exposure.

5.2 When conducting exposures in devices that use laboratory light sources, it is important to consider how well the artificial test conditions will reproduce property changes and failure modes associated with end-use environments for the sealant being tested. Information on the use and interpretation of data from accelerated exposure tests is provided in Practice G151.

5.3 When this test method is used as part of a specification, exact procedure, test conditions, test duration and evaluation technique must be specified. Results obtained between the two procedures may vary, because the spectral power distribution of the light sources (fluorescent UV and xenon arc) differ. Sealants should not be compared to each other based on the results obtained in different types of apparatus.

5.4 These devices are capable of matching ultraviolet solar radiation reasonably well. However, for sealants sensitive to long wavelength UV and visible solar radiation, the absence of this radiation in the fluorescent UV apparatus can distort color stability ranking when compared to exterior environment exposure.

Note 1: Refer to Practice G151 for full cautionary guidance regarding laboratory weathering of non-metallic materials.

Subcomité:

C24.40

Referida por:

C1021-08R23

Volúmen:

04.07

Número ICS:

91.120.30 (Waterproofing)

Palabras clave:

artificial accelerated weathering; sealants; color change; color stability;