PET BOTTLE FAULTS AND SOLUTIONS. - Blow Moulding Controls

27. DROP TEST FAILURES
DESCRIPTION/FAULT:
Bottles burst open in the base when drop test is carried out.
CAUSE:
1. Preform end cap blown too cold.
2. Heavy base weight (unorientated material).
3. Excessive crystallinity in preform base.
4. Low IV.
5. Poor base design – sharp edges between feet and at the punt.
SOLUTION:
1. Increasing heat at the gate or below without losing base weight usually
improves drop test failure.
2. Reduce base weight if above specification.
3. Review base design.