6.1 Introduction

As previously outlined in Chapter 1, the term injection blow moulding is the compatible integration of two processes, injection moulding and blow moulding. This integration system is one, which is designed exclusively for injection blow moulding with a plasticiser, hydraulically operated clam unit, electrical controls, other machine components and functions. See Chapter 1, Section 1.2.1.4 for the advantages of this process.

As with extrusion blow moulding it is a two-step process. The first stage consists of injection moulding the preform in a mould consisting of a cavity and a hollow core. The second involves moulding and cooling in a follow-on mould (see Figure 6.1). The preform is injection moulded at a temperature which is in the temperature range of the moulding resin and blown at a temperature in the thermoplastic range. Products made by the injection blow moulding process are shown in Figure 1.8 and Table 6.1. Materials (resins) suitable for injection blowing are given in Table 6.2.

Figure 6.1: Basic injection blow mould