The notched impact strength at -30 °C is one of the selected properties, together with the corresponding
test method and tolerances, for a comparison of polyethylene grades of one design type in the procedural
rule on suitability proof for alternative plastic resins used for packagings and intermediate bulk
containers (IBCs) for the transport of dangerous goods.
The marginal drop heights determined with the drop test at -18 °C after pre-storage of the test samples
with 55 % nitric acid at 40 °C only partly related to the notched impact strength at -30 °C. The Charpy
method is only suitable for classifying the grade in relation to toughness behavior and using this classification
for comparison with other grades. Notched impact strength can provide a qualitative indication if
the test samples fail under shock forces.
Conditioning the design types with 55 % nitric acid for 21 days at 40 °C causes an increase in the marginal
drop heights of the design types in drop tests at -18 °C when compared with design types without
pre-storage. Post-crosslinking of the grades increases stiffness because of the acidic influence.
Key words: dangerous goods packagings, polyethylene grades, notched impact strength at
-30 °C, design type tests, pre-storage with nitric acid