Chemical Engineering Seminar

The most common process for manufacturing plastic bottles is Injection Stretch Blow Moulding (ISBM), which is primarily used to manufacture Polyethylene Terephthalate (PET) bottles for the carbonated soft drink (CSD) and water industries, a global market estimated to grow to £57B by 2017. Due to environmental concerns and the volatility of resin cost, there is a continual drive to lightweight these containers. The same process is also used in the manufacture of medical devices such as angioplasty balloons and biodegradable scaffolds where the biaxial deformation induced during forming is used to improve stiffness and strength.

ISBM begins with injection moulding of a test tube like specimen or the extrusion of a tube, known as a preform that is subsequently re-heated above its glass transition temperature and formed into a mould by a combination of axial stretching through a mechanical actuator and radial stretching by internal air pressure. The main challenge for manufacturers of bottles is to produce them with as little material as possible but still meet in-service performance requirements such as top load and burst resistance whilst the main challenge for medical devices manufactured is to produce them with controlled thickness distribution and mechanical properties.

The talk will present a summary of 20 years of research on developing a numerical simulation of the ISBM process for both PET containers and medical devices.  It will cover aspects of material modelling and characterisation, process instrumentation, experimental mechanics and finite element modelling.