1. Feeder Glass too hot   1. Feeder Adjust gob temperature   2. Machine Setup and Operation Neck ring is running too hot Insufficient settle blow time or pressure Too high production speed Excessive final blow pressure Take-out tongs not in line, or incorrect timing Insufficient finish cooling Plunger contact time too short (press and blow) Plunger up pressure too low (press and blow) Blow head not central   2. Machine Setup and Operation Use neck ring cooling nozzle Increase settle blow time and/or pressure Reduce the machine speed Reduce the final blow pressure Realign take-out tongs and check the timing Increase plunger up pressure Increase plunger contact time Increase cooling wind Centralize the blow head over the blow mold   3. Mold Equipment Neck ring out-of-round due to poor cleaning process Blow head improperly vented Take-out tongs too small Equalizing vents not correct or plugged in blow head Take-out tongs not square Neck ring spring weak   3. Mold Equipment Change neck ring Correct venting of blow head Check take-out tongs for dimensions Realign take-out tongs of dimensions Check mold neck for oval. Correct if necessary Change the neck ring holders