1. Feeder
  • Blister in glass
  • Gob shape too pointed ( P&B )
  • Incorrect oil/water ratio for shear spray
  • Water in delivery

 
1. Feeder
  • Obtain good thermal Homogeneity and blister free glass
  • Adjust gob shape so gob does not slide down one side of plunger
  • Have enough lubricant to maintain good shear cut
  • Do not use excessive shear spray, catch residue if possible
2. Machine Set-up
  • Gob loading at correct height
    ( NNPB, P&B )
  • Wrong delivery alignment

 
2. Machine Set-up
  • Adjust loading height, by plunger spacers and/or stop screws, for correct gob load
  • Make relevant delivery adjustments
3. Mould Equipment
  • Plunger profile incorrect

 
3. Mould Equipment
  • Plunger profile too narrow amend as necessary