DESIGN OF BLOW MOULD DIE FOR POLYPROPYLENE BOTTLE WITH MULTIPLE OPENINGS

Abstract

Blow holding is the forming of a hollow part by blowing a mould cavity shaped parison made by thermoplastic molten tube. Blow moulding is generally suitable for manufacturing thermoplastic products which have only one side open. The present work deals with a die design to produce a bottle having openings at two ends. The product here is a 1500 ml top up bottle used in solar industry with open ends at top phase and bottom phase. The bottle openings had ¾” BSP external thread at one end and ¾” NPT external thread at the other end. The raw material of the product is Polypropylene. Die design includes the numerical analysis of blow pressure, air vent, Orifice size and blow time for better product. The die material was EN8 medium carbon steel. By the reference of journals it was possible to determine the method of parison wall thickness control, properties of EN8 medium carbon steel, Double Dam pinch off design. As per the design specifications, the final CAD is modelled using Pro-E software and structural analysis in Ansys software