1. Feeder Glass too cold 1. Feeder Increase glass temperature 2. Machine Set-up Temperature of mould equipment too low Plunger pressing pressure too high ( P&B, NNPB ) Plunger mechanism out of line ( P&B, NNPB ) Baffle arm setting too low 2. Machine Set-up Increase mould equipment temperature by cooling and/or modification Reduce plunger pressing pressure Re-align mechanism with jig Adjust baffle setting   3. Mould Equipment Poor mould equipment joints, blank side 3. Mould Equipment Bring joints back to standard