Research: Transferability of material parameters from the testing of high density polyethylene grades to the selective testing of packaging and IBC

In coordination with European associations, experts from the industry (manufacturer of polyethylene moulding material and of plastics packaging or IBC) as well as with the competent authorities and testing laboratories are defined in the Dangerous Goods Rule 003 of the BAM – Packaging – Transport packaging for dangerous goods – Comparative material testing of polyethylene grades – the preconditions for the use of alternative plastics moulding material for the production of packaging an IBC. This dangerous goods rule is presently still a hypothesis which has to be proved by more testing of specimens and design types in the praxis.

Packaging for dangerous goods made of plastics can be damaged by chemicals and by the stress during the transport with different processes/mechanisms such as stress cracking, embrittlement at low temperatures, swelling/soften plastically as well as molecular degradation.

In the international regulations for design type testing are described testing procedures which determine and evaluate the real stress conditions of the design type during the transport of solid and liquid dangerous goods. It is important for the approval testing of a special design type by changing a grade of plastics moulding material if a special design type test is necessary or not. It is a precondition for such a walving that the required limits of the specific material parameters in the Dangerous Goods Rule 003 of the BAM are kept. Walving of tests is for the applicant of the industry finally connected with saving of costs and time.

There are used the parameters melt flow rate MFR, density D, low temperature notched impact strength NIS., environmental stress crack resistance FNCT and molecular degradation OX in the Dangerous Goods Rule 003 of the BAM for the comparison of polyethylene grades. These parameters are determined with specimens prepared of compression moulded sheets. They describe practical properties of grades of high density polyethylene, used for the manufacture of packaging and IBC.

There are presently no scientific confirmed conclusions available if the results of the comparison of the properties of high density polyethylene grades in consideration of the criteria in the Dangerous Goods Rule 003 are comparable with the results of the design type testing (drop test, leakproofness test, hydraulic pressure test, stacking test) of packaging and IBC made of these HDPE. The possibility of the t ransferability of the material parameters of high density polyethylene grades to the selective testing of packagings and IBC has to be checked.

Within the scope of this project it has to be determined on the basis of test series with selected HDPE grades if the ranking of the properties of polyethylene grades on the basis of the evaluation according the Dangerous Goods Rule 003 and on the basis of the evaluation of the results of the design type testing of packaging made of these grades lead to the same conclusion.

Furthermore it will be pointed out if the verification of the suitability of alternative plastics moulding materials for packaging and IBC is based on the suitable material properties and evaluation criteria.

This research topic is handled together with department III [contact person: Mrs Dipl.-Chem. Margit Weltschev (III.2) and Dr. rer. nat. Peter Blümel (III.1)]