ASTM D904-99(2021)

4.1This practice is for determining the effects of UV light, or UV light and water, on adhesive bonded joints under controlled but artificial conditions. The results of this practice can be used for comparing the relative durability of several adhesives in a specific laboratory UV exposure.

4.2This practice is not for determining a forecast of the life of an adhesive bond in service. It is only for determining the relative durability of different adhesives compared to each other.

4.3The results obtained may vary between the different light sources (xenon-arc or fluorescent UV), because of the different spectral-irradiance of the lamps. Adhesives should not be compared to each other based on their performance under different types of light sources.

4.4The results obtained may vary when operation conditions are varied within the limits of a given method. The results may also vary when exposures are performed on instruments made by different manufacturers. Comparisons between materials must only be made when they are tested at the same time in the same instrument. Be sure to accurately report the operating conditions.

4.5The type and UV transmittance characteristics of the transparent adherend used can have a significant effect on the rate and type of degradation of the adhesives being tested. Comparisons between adhesives must only be made when tested on transparent adherends of the same type (preferably the same lot) with the same UV transmission.

4.6This practice is not for determining the effects of atmospheric pollutants, biological organisms, salt, or freeze/thaw cycles.

1.1This practice covers the basic principles and operating procedures for ultraviolet (UV) light aging (with or without water) of adhesive bonded joints having at least one glass or transparent adherend, using fluorescent UV (see Method A) or xenon-arc light sources (see Method B).

1.2This practice is limited to the apparatus for obtaining, measuring, and controlling the aging conditions, and to the procedures for exposure. Sample preparation, strength, test conditions, and evaluation of the results are described in other ASTM test methods or specifications.

1.3The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.