ISO 4628-5:2016 pdf free
ISO 4628-5:2016 pdf free.Paints and varnishes – Evaluation of degradation of coatings
This part of ISO 4628 specifies a method for assessing the degree of flaking of coatings by comparison with pictorial standards.
ISO 4628-1 defines the system used for designating the quantity and size of defects and the intensity of changes in appearance of coatings and outlines the general principles of the system. This system is intended to be used, in particular, for defects caused by ageing and weathering, and for uniform changes such as colour changes, for example yellowing.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 13076, Paints and varnishes一Lighting and procedure for visual asessments of coatings
3 Terms and definitions
For the purposes of this document, the fllowing terms and definitions apply.
3.1 degree of flaking
rating characterizing flaked areas in a coating in terms of quantity, size, and depth
4 Assessment
Assess the quantity of flaking by reference to Table 1 and using as examples Figure 1 or Figure 2, depending on the type of flaking.
NOTE Figure 1 shows flaking without preferential direction and Figure 2 shows flaking in a preferential direction due to anisotropy of the substrate.
Where a test area exhibits flaked areas of various sizes, quote as the size rating that of the largest areas which are numerous enough to be typical of the test area.
If possible, indicate the depth of flaking by reference to the level in the coating system where failure occurs. A distinction is made between two main types of failure by flaking:
a) coat(s) flaking from underlying coat;
b) the whole coating system flaking from substrate.
Carry out the assessment under good ilumination, as specified in ISO 13076.ISO 4628-5 pdf download.
