BS ISO 4658:2020

What is ISO 4658 about?  

ISO 4658 specifies, for acrylonitrile-butadiene rubbers (NBRs): 

• Physical and chemical tests on raw rubbers 
• Standard materials, a standard test formulation, equipment and processing methods for evaluating the vulcanization characteristics 

The preferred mixing method is the single-stage mixing with LIM (laboratory internal mixer). 

Who is ISO 4658 for? 

ISO 4658 on evaluation of acrylonitrile-butadiene rubber (NBR) is useful for: 

• Rubber manufacturers/ processors 
• Automakers 
• Packaging/sealing industry 

Why should you use ISO 4658?  

Acrylonitrile-butadiene rubber (NBRs) is known for its oil resistance properties. This makes it suitable for use in gasket and fuel hoses. To produce high-quality rubber, you need to pay close attention to each and every aspect of its production.  

ISO 4658 provides you with the complete evaluation procedure for NBRs. ISO 4658 provides you with the reference of appropriate documents to evaluate the physical and chemical properties of NBRs. ISO 4658 will also provide you with test method procedures to evaluate whether the physical requirements for NBRs are being met during the vulcanization process. ISO 4658 helps you to verify your NBRs production quality. 

What’s changed since the last update?  

BS ISO 4658:2020 replaces ISO 4658:1999, which has been technically revised. BS ISO 4658:2020 also incorporates the Amendment ISO 4658:1999/Amd.1:2004. 

The main changes compared to the previous edition are as follows: 

• Clause 2 has been updated 
• The mixing procedure has been specified: method A1 for single stage mixing with LIM is the preferred method; method A2 is for two stages mixing using a LIM for initial mixing and mill mixing for final mixing; method B deals with mill mixing 
• The precision data have been moved to Annex A