The Internal Pressure Test in Experiment and Simulation—Influence of the Wall Thickness Variation and the Change of the Packaging Behavior after the Impact of Standard Liquids

Abstract

The effect of the wall thickness variation of blow-moulded bodies made of high-density polyethylene on an internal pressure test after prestoring the packaging with standard liquids was evaluated in experiments and simulations. The objects of the investigation were jerrycans used for the transportation and storage of dangerous goods.The wall thickness was determined using two alternative methods to the magnetostatic measurement. These alternative methods are used for research purpose to get a volumetric model of the jerrycan wall as a geometric model for the simulation. The comparison of the experiments and the simulations of the internal pressure test were performed using the digital image correlation method. The integral strain and deformation of the whole jerrycan was detected by measuring the total mass of the jerrycan being filled with water during the internal pressure test. This is a suitable alternative to the optical measurements of local deformation by the digital image correlation method. Prestorage at 40 C without the influence of chemicals strengthens the jerrycan, whereas the swelling effect of butyl acetate and hydrocarbon mixture softens the jerrycan. The comparison with the experiment is necessary to verify the accuracy of the simulation. It shows that the deformation can be simulated more precisely by using the actual measured geometry. The weakening of the high-density polyethylene caused by a hydrocarbon mixture can be simulated using the Arrhenius equation. The aim of the simulation was to discover whether it is possible to use specimens to predict the behaviour of a packaging both after the influence of standard liquids.

Combined impact of UV radiation and nitric acid on high‐density polyethylene containers as a laboratory test

“…The jerrycan grows into an almost spherical balloon and holds up to 170% of its original volume. Such visco-plastic deformation behaviour in combination with the ductile failure was also observed by Menrad,8 after 21 days prestoring at 40 C with specific standard liquids, among others HNO 3 -55%.…”

“…A hydraulic internal pressure test was carried out for all jerrycans after the respective exposure. 8 This test is very close to a typical mechanical container stress in later use. The jerrycan lid was equipped with two valves, one for the water inlet and a second for the pressure sensor.…”

Drop Test of Plastic Packagings – Correlation with Material Parameters and Change of Packaging Behaviour After Impact of Standard Liquids

“…For the determination of every 50% failure drop height, 25 jerrycans were examined. The same packagings were examined at the work of Menrad et al . for their internal pressure behaviour.…”

“…Because this height is more than 2‐m higher than the 50% failure drop height in the original state, no further tests were carried out pre‐stored with hydrocarbon mixture. The swelling effect is not critical for the drop test unlike for the internal pressure test as described in the paper of Menrad et al …”

“…Packagings for the transportation of dangerous goods have to withstand different experimental tests to show their eligibility for approval. Along with the internal pressure test, which is analysed in a study by Menrad et al ., and the stacking test, a drop test has to be performed. The exemplary packagings being examined in this paper are jerrycans, blow moulded hollow bodies made of high‐density polyethylene (HDPE).…”