BS EN ISO 4628-2:2016

What is ISO 4628-2 - standard for paint coating degradation about?  

Paints and coatings of all types are widely used to provide colour and pleasing aesthetics, and to prevent deterioration of the underlying substrate when exposed to various environments. Besides protection and beauty, however, coatings provide light reflectivity, camouflage surfaces, reflect and absorb heat, and provide a variety of other functions. With exposure to environmental factors, coatings degrade over time. This leads to crack initiation, propagation & delamination. If the coating is overheated, it can lead to loss of mass or decomposition and ingress of aqueous media can lead to change in the chemical composition of the coating as well.  

ISO 4628-2 is part of the ISO 4628 series on the assessment and analysis of paint and varnish degradation due to weathering and age. ISO 4628-2 specifies a method for assessing the degree of blistering of coatings by comparison with pictorial standards. The pictorial standards provided in ISO 4628-2 illustrate blisters in sizes 2, 3, 4, and 5, and each size in the quantities (densities) 2, 3, 4, and 5. This system is intended to be used for defects caused by ageing and weathering, and for uniform changes, for example, yellowing.  

Who is ISO 4628-2 - standard for paint coating degradation for? 

ISO 4628-2, the standard for paint coating degradation is useful for: 

• Manufacturers of paints and varnishes 
• Concerned maintenance teams 
• Product development teams 
• Quality control teams 

Why should you use ISO 4628-2 - standard for paint coating degradation?  

Most of the protective coatings perform well until an old age, at which time natural deterioration and degradation occur. Energy acting on a coating can degrade a material by breaking or interfering with the chemical bonds holding the resin together and to a substrate.  

ISO 4628-2 walks you through the assessment techniques for evaluating the degradation of coatings and designate the quantity and size of defects. ISO 4628-2 discusses the intensity of uniform changes in appearance and guides you in assessing the degree of blistering. This helps you to design better products and mitigate weathering challenges for coatings, so that your customers can enjoy long-lasting products. 

What’s changed since the last update?  

BS EN ISO 4628-2:2016 supersedes BS EN ISO 4628-2:2003. BS EN ISO 4628-2:2016 includes some technical changes with respect to BS EN ISO 4628-2:2003. These include: 

• A normative reference to ISO 13076 for illumination for the assessment has been added 
• A note concerning the visibility of S1 size of blisters has been added