Practical Guide to the Assessment of the Useful Life of Rubbers

by R. P. Brown

Pages: 156

 

After price and delivery time, the most frequently asked question about a product is "How long will it last?" This is usually a very difficult question to answer for rubber products because the expected lifetime is often in tens of years, the service conditions may be complex, and there is a scarcity of definitive data on durability. There is a vast matrix of degradation agents, service conditions, properties of importance and different rubbers.

There are also many inherent difficulties in designing tests. In many cases, the timescale involved is such that accelerated test conditions are essential. Whilst large amounts of durability data are generated by accelerated methods, much of it is only useful for quality control purposes and relatively little has been validated as being realistically capable of representing service.

Most assessments of lifetime of rubbers are made by considering some measure of performance, such as tensile strength, and specifying some lower limit for the property, which is taken as the end point. Lifetime is not necessarily measured in time. For example, for some products it will be thought of as number of cycles of use.

The object of this publication is to provide practical guidance on assessing the useful service life of rubbers. It describes test procedures and extrapolation techniques together with the inherent limitations and problems. The Guide aims to make available the wealth of information that can be applied to help maximize the effectiveness of a durability testing program.

This guide seeks to be comprehensive but concentrates on the most common environmental effects causing degradation and the most important mechanical properties of rubbers. The test procedures used are outlined and the relevant textbooks and International standards are referenced.

Rapra Technology has just completed a 40 year natural ageing program and an accelerated testing program, both on the same set of rubber compounds. The results have been drawn on in this Guide to indicate the limiting factors for particular test methods.

 

Members: $130.00

Non-members: $144.00

 

Item # RAP005

 

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