Characterising the Mechanical Properties of Polymers used in Sterile Barrier Systems

Polymers are widely used in the manufacture of sterile barrier systems for the healthcare sector. Sterile barrier systems are packaging systems utilised in medical, pharmaceutical and diagnostic applications where the content of the package requires post-packaging sterilisation. Products such as bags, pouches and thermoformed trays can be manufactured from thermoplastics such as polypropylene, polyethylene, polystyrene and polycarbonate. Prior to forming, single-layer or multi-layer sheet first undergoes extrusion and is then wound on a roll. The extruded roll-stock is then formed by a secondary process into final packaging components. The various stages in the production processes subject the materials to varying temperatures, pressures and stresses and the result of these variations in the production processes generally leads to variation in the mechanical properties of the final components and in particular the heat sealability of the components. Increased demands from regulatory authorities over concerns about patient safety have led manufacturers to seek new ways to improve their process technology and product quality with a view to reducing the variation in these mechanical properties. This paper discusses the use of polymer analysis to gain better understanding of some of these material properties and how they can influence product quality.