BS ISO 4660:2020

What is ISO 4660 about?  

ISO 4660 specifies two methods to determine the colour of raw natural rubber according to a standard colour scale: 

• Method A: colour matching against standard coloured glasses 
• Method B: colour determination using colour spectrophotometer 

In case of dispute, the preferred method is Method B. 

Who is ISO 4660 for? 

ISO 4660 on colour index test for natural rubber is useful for any industry that uses rubber products. Specific users of ISO 4660 can be: 

• Rubber manufacturers/processors 
• Tire manufacturers 
• Automakers 
• Shoemakers 
• Quality control personnel 

Why should you use ISO 4660?  

The natural rubber has unappealing colour to it, that’s why manufacturers like to dye their rubber products in colour before using it in their final product. However, the physical properties of rubber make it difficult to maintain the consistency of colour throughout. 

ISO 4660 provides you with two colour index tests for natural rubber: matching against standard coloured glass and spectrophotometer.  ISO 4660 gives you a detailed account of these methods ensuring that you perform these test methods accurately. This will help you to maintain colour consistency in rubber material ensuring a quality finish to your products. 

What’s changed since the last update?  

BS ISO 4660:2020 replaces ISO 4660:2011, which has been technically revised. The main changes compared to the previous edition are as follows: 

• A colour spectrophotometer has been added as an alternative method to determine colour index in Clauses 1, 4 and in 5.8 
• The thickness of the material from the punch, in 5.4, has been specified to be 3,4 mm ± 0,2 mm 
• The thickness of the final sheet from the mill, in 6.1, has been specified to be 1,7 mm ± 0,1 mm 
• The calibration for colour spectrophotometer has been added in 6.2 
• The procedure for colour determination using colour spectrophotometer has been added in 6.3.2