1. Feeder Gob temperature is too high   1. Feeder Adjust gob temperature   2. Machine Setup and Operation Parison is too soft Plunger contact time too short Counterblow too soon Counterblow pressure too high Plunger too hot Final blow too late   2. Machine Setup and Operation Advance counterblow and increase blank contact time Increase plunger contact time Retard counterblow timing Reduce counterblow pressure Increase plunger cooling time Advance the final blow time   3. Mold Equipment Plunger tip too short Incorrect plunger design   3. Mold Equipment Lengthen plunger tip Correct the plunger design