Validation of an Alternative Method for Testing the Chemical Compatibility of Liquids with Polyethylene Packagings for Dangerous Goods

Abstract

Safety risks may ensue when the chemicals contained in polyethylene packagings a age and damage them. To prevent subsequent accidents, the European Dangerous Goods Regulations have laid down requirements for testing the chemical compatibility of liquid dangerous goods transported in polyethylene packagings. The test procedures include 6 months in which the chemical is prestored in the packaging. After this time, the respective design-type tests are performed. Alternative methods with so-called standard liquids, simulating the different types of damaging effects, are also possible. If a packaging has successfully passed the design type tests with a standard liquid, other dangerous goods may also be transported in this packaging, as long as it is demonstrated that they have a less damaging effect than the standard liquid. However, in this area there is only little information and research available.A new potentially effective and time-saving method for comparing the stress crack damaging influence of liquids with standard liquids was proposed by a major German chemical company.The validation of this method, which was carried out on two polyethylene materials, showed the general applicability of the method. Two kinds of wetting solutions were applied to simulate cracking under stress.The influence of prestorage, test temperatures, wetting agents and material was examined. FEM calculations were carried out to ascertain the influence of the sample shape.

The impact of impurities on the mechanical properties of recycled polyethylene

“…For the use in non‐food bottles, the rPE has to have a high stiffness, high impact resistance, a low MFI and should be easy to extrude. For some bottle applications, a high resistance to environmental stress cracking is an additional requirement 33,34 . Because impact resistance is coarsely related to the resistance for environmental stress cracking and less laborious to measure, it is used as indicative parameter.…”