Description of Activity1. Presentation of Abstract- Title: Environmental Stress Cracking of Polyethylene Based Medical Devices
Low density Polyethylene (PE) based polymeric medical devices such as medical tubing have been observed to fail in real life situations as a result of environmental stress cracking (ESC) occurring due to the combined effect of a low level of mechanical stress combined with chemical exposure. ESC can result in catastrophic failures of products including medical devices during their service life without any visible warnings. To investigate this, the ESC behaviour of PE based samples used in medical tubing was investigated experimentally using both the ASTM D1693 and ISO 22088-3 test standards. Injection moulded PE samples were produced with varying amounts (2-8%) of Ethylene Vinyl Acetate (EVA) and with two types of additives (a pigment and an antimicrobial agent) before being exposed to two solvents commonly used as assembly aids (MEK and IPA). EVA an elastomeric polymer, was blended with PE in an attempt to increase ESC resistance, by improving the toughness. It was found that the addition of the additives made the material more susceptible to ESC and that the addition of EVA afforded a degree of protection against stress cracking. It is believed that findings from this work will be helpful across a range of industries by helping to reduce the risk of unexpected ESC failure of safety critical PE components.
2. Presentation of Abstract- Title: An Analysis of Rotationally Moulded Sandwich Structure’s Repeated Impact Properties.
Repeated impact properties of fully recyclable rotationally moulded polyethylene (PE) sandwich samples were experimentally investigated in this work. Testing was carried out with an impact force sensor attached drop weight impactor at 20 J to 50 J energy levels. These sandwich structures used in marine, automotive, large tanks and other applications, are susceptible to small damage due to impact events with floating debris, collisions or friction with other vehicles, crafts etc. in their service life which can grow with time and repeated impacts leading to a catastrophic failure. To avoid this unexpected situation, an in-depth understanding of repeated impact properties of this sandwich structure is essential. The repeated impact properties were analysed in terms of impact force-deflection, maximum impact force, impact damage and the total number of repeated impacts needed for sample penetration. A lower impact energy level showed a higher total repeated impact events to penetrate sandwich samples fully. The maximum impact force vs the repeated impact number figure exhibited three different regions which are related to the damage mechanisms of tested rotationally moulded sandwich samples.
|Period||26 Sep 2021 → 29 Sep 2021|
|Location||Quebec, Canada, Quebec|