What is BS EN 12877-4 – Determination of colour stability by two-roll milling about? 
BS EN 12877 is a European Standard that discusses the determination of colour stability to heat during processing of colouring materials in plastics. The aim of the BS EN 12877 series is to provide plastic manufacturers with best industry practices to demonstrate the performance and quality of their products.
BS EN 12877-4 describes a method for determining the colour stability of colouring materials in plastics under defined conditions in plastics by two-roll milling. The result of the determination is a relative value, not an absolute one. The method is mainly used for testing colouring materials in polyvinyl chloride.
Who is BS EN 12877-4 - Determination of colour stability by two-roll milling for? 
BS EN 12877-4 on the determination of colour stability of plastics to heat stress is useful for: 
- PVC and thermosetting material manufacturers
- Manufacturers and suppliers of additives for plastics
- Plastic product manufacturers
- Plastic industry
- Quality control and testing personnel
Why should you use BS EN 12877-4 - Determination of colour stability by two-roll milling?
When PVC is heated, it undergoes a series of colour change, from light to dark. Based on this colour change taking place within a specific time frame, one can judge the extent of degradation of the PVC. Thus, the colouring materials added must be capable of withstanding the exposure to thermal stresses.
BS EN 12877-4 walks you through the two-roll milling method for determining the colour stability of colouring materials under the influence of the thermal stress encountered during plastics processing.
By complying with best industry practices recommended by BS EN 12877-4, you can determine colour fastness of colouring material, thus ensuring that the additives and materials used in PVC plastics meet the necessary performance requirement. Thus, through this test, you can assess whether or not the PVC can inhibit colour change.
