Preform design
The most important parameters when designing a preform, in order to achieve the required container specifications with the lowest weight, fastest cycle time, widest process window and ease of filling, are:
- Wall thickness (WT)
- Bottom wall thickness (BWT)
- Total length (TL)
- Preform overall shape (i.e. straight, bell, reverse taper)
- Neck finish size and diameter
- Neck/Thread thickness
- HUS Height Under Support Ledge
- Under-ring diameter/thickness/transition area profile
- Total Weight
- Injectability
- Length/wall thickness ratio (L/t)
- Blowability (stretch ratio)
- Axial stretch
- Radial stretch
- Total stretching ratio