Parison formation cooling

Blow-molding processes consists of five main operations plastication of the resin, formation of the parison, inflation of the parison, solidification of the part, and removal of the part from the tooling. The best process economics will occur with a part optimized for weight and a minimum cycle time. In order to have a minimum cycle time, the cooling operation must be the rate-limiting step. For the case study... 

Coolant systems are an integral part of container formation and serve to cool the molds and, if applicable, the parison clamp assembly. Coolant, although not in direct contact with product pathways, is in close proximity to the containers, and maintenance should be carried out to prevent leakage. Coolant systems are prone to microbiological contamination and should be routinely treated to keep the bioburden imder eontrol. They should be regularly sampled and tested for bioburden to ensure continuous compliance to a predefined specification. 

They have in common the formation of the precursor, a simple hollow tube known as a parison. One end of the parison is closed (for instance, simj nipped) so that it can be inflated in the heated, softened state. If inflates until it touches the walls of the cooled mould. The parison at once takes up the shape of the mould and cools. The mould is then opened and the bottle removed. 

---