Tubular film blowing - myths and science

Film blowing "is a process which is geometrically complex and where there is a strong desire for simple ideas. There is no guarantee that such simplicity can be found, and part of the theorist's task here is the rather negative one of curbing the enthusiasm of would-be simplifiers" [1]. This paper uses the simplest model of the process to address some persistent misunderstandings (e.g. about so-called intuitive and counter-intuitive behaviour) and to review the complex interaction between all the processing parameters. An elementary approach to some questions about bubble stability is discussed.