1. OBJECT AND FIELD OF APPLICATION
The object of this méthode is to assess the resistance of a paint coating to the action of a reagent simulating
attacks from a biological source (for example the action of bird droppings).
2. PRINCIPLE
The test consists of subjecting a paint coating to an artifical ageing cycle, depositing a reagent simulating
biological attacks, then drying and dissolving it.
This test is expanded by an adhesion test carried out by means of an adhesive tape on the paint coating
portion where the reagent has been deposited.
The deterioration observed is graded in relation to a classification consisting of 7 typical photographs..
3.13 GUM ARABIC SOLUTION
· Weigh 10 g ± 0,1 g of gum arabic (3.12) using the balance (3.6).
· Dissolve the gum arabic in 10 g ± 0,1 g of drinking water.
· Homogenise the solution and leave to rest for a minimum of 3 days in a closed flask, before use.
Note : The age of this solution is important and must be recorded in the test report. It must be between 3
and 7 days.
4. PREPARATION OF TEST SPECIMENS
· The dimensions of the test specimens must be such that they can be fitted onto the Weatherometer
(3.3) supports, see méthode d’essai D27 1389.
· It must be possible for the test to be carried out in at least two different locations on the test specimen
10 millimetres apart and 10 millimetres from the edge.
· The type of substrate, its surface preparation, the conditions of application and drying of paint films
must correspond to the use of the products to be examined.
· The designation of each layer of paint coating must be recorded and indicated in the test report.
· For test specimens produced in a laboratory, the thickness of each paint coating layer must be
recorded and indicated in the test report.
· For test specimens taken from the component, the total thickness of the paint coating must be
recorded and indicated in the test report.
· The surface of the test specimen must be clean and free from defects.
Provide between 5 and 10 test specimens for the test.
参考资料:这个和别的涂层表面质量测试的概念和流程是差不多的。