How PET Bottle Geometry Influences Preform Mould Design

A PET preform should never be designed by considering weight alone. The final bottle geometry plays an important role in determining the required preform design.

Bottle height, diameter, shoulder profile, base geometry and neck finish all influence how PET material must stretch and distribute during stretch blow moulding.

For example, a tall, narrow bottle and a short, wide bottle of similar volume can require different preform geometries because the material experiences different axial and radial stretching. Complex shoulders, grip areas and specialised bottle bases can create additional material-distribution requirements.

Engineers therefore evaluate factors such as:

• Bottle dimensions and capacity
• Neck finish
• Required preform weight
• Wall thickness distribution
• Stretch characteristics
• Bottle base and shoulder geometry
• End-use performance requirements

Getting these parameters right helps produce bottles with more consistent wall distribution, strength and appearance.

LEO Precision develops PET preform mould solutions around the customer's packaging and production requirements, helping manufacturers move from bottle concept towards reliable moulding. The right PET bottle begins long before blowing starts.

It begins with a preform engineered for the bottle it must become.