BS ISO 16770:2019
$167.15
Plastics. Determination of environmental stress cracking (ESC) of polyethylene. Full-notch creep test (FNCT)
| Published By | Publication Date | Number of Pages |
| BSI | 2019 | 34 |
This document specifies a method for determining the environmental stress cracking (ESC) resistance of polyethylene (PE) materials in a defined test environment. The test is carried out on notched test specimens machined from moulded sheets/specimens or from finished products. The test specimen is subjected to a static tensile load when immersed into an environment such as a surfactant solution held at a specified temperature. The time to failure is measured.
The method has been specifically developed for polyethylene materials but can be used to evaluate PE products, such as pipes, fusion welds/fittings and blow-moulded PE containers to study the effect of aggressive environments, i.e. dangerous goods and chemicals.
The method is suitable for use with test specimens moulded to chosen dimensions or machined from compression moulded sheets or injection moulded specimens, or from finished products, such as mouldings and pipes. When the test specimens are machined from extruded or moulded parts, the results can be affected not only by properties of the material, but also by stresses or orientation introduced during processing.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 2 | National foreword |
| 6 | Foreword |
| 7 | Introduction |
| 9 | 1 Scope 2 Normative references 3 Terms and definitions |
| 11 | 4 Principle 5 Apparatus |
| 14 | 6 Test specimens 6.1 General 6.2 Test specimens geometry |
| 16 | 6.3 Test specimen preparation 6.3.1 General 6.3.2 Test specimens machined from compression moulded sheets 6.3.3 Test specimens machined from injection-moulded type 1A multipurpose test specimen 6.3.4 Test specimens machined from finished products 6.4 Test specimen notching |
| 17 | 6.5 Conditioning of the test specimens 7 Test environment 7.1 General 7.2 Recommended test environment 7.2.1 Test environment No. 1 |
| 18 | 7.2.2 Test environment No. 2 |
| 19 | 7.3 Other test environments 8 Test procedure 8.1 Selection of detergent, reference tensile stress and test temperature 8.2 Number of test specimens to be tested |
| 21 | 8.3 Calculation of the test load 8.4 Application of the load to the test specimen 8.5 Removing individual specimens from a chamber 8.6 Measurement of the ligament area after failure |
| 22 | 9 Expression of results 9.1 Calculation of the actual tensile stress 9.2 Calculation of time to failure at the reference tensile stress |
| 23 | 10 Precision 11 Test report |
| 25 | Annex A (informative) Precision statement |
| 28 | Annex B (informative) Example of a recommended test report for FNCT determination |
| 30 | Annex C (informative) Practical examples of fracture surfaces and corresponding definition of failure mode |
| 33 | Bibliography |
