1. Feeder Gob temperature incorrect   1. Feeder Check setting of gob temperature. Adjust if necessary   2. Machine Setup and Operation Mold closes too soon or too fast Mold holders are badly worn Neck ring holders bent Neck ring arms not square Take-out tongs close too fast Take-out tongs are wet with oil Take-out tongs are out of line Parison is not setting down in mold so that blowhead pushes finish downward Worn blank linkage causes one side of blank to go past the center, setting up a strain as blank opens Neck ring holders set too low on blow mold causing strain on neck ring during blank opens Neck ring opening too fast Plunger mechanism too high or too low. If plunger is too high it pushes up the neck ring and causes it to slide against the blank when opening. If too low, the blank will lift the neck ring when closing or opening Bottom plate too high or too low Too much cooling wind on the nozzles Poor and irregular mold swabbing Offset mold in top plate Invert to slow-transfer on the fly Invert bouncing over mold Blowhead exhaust, too much finish cooling down before takeover picks up Check deflection bracket on mold-side   2. Machine Setup and Operation Adjust mold closing action Check mold holder for dimensions according to repair data Check neck ring holders to repair drawing dimensions Check invert mechanism with neck ring aligning fixture Retard closing of take-out tongs Take-out tongs should be checked to remove any oil Take-out tongs should be checked for alignment Mold neck to be checked for correct size and shape Mold opening and closing linkage should be renewed Check neck ring, adjust using neck ring setting gauge if necessary Adjust neck ring opening for smoother action Check for relief on mold shoulder radius Adjust the setting of the bottom plate mechanism for correct height Reduce the cooling wind on the molds and check the cooling wind setup Swab regularly with a clean and dry swab of correct shape   3. Mold Equipment Neck diameter of blank is larger than neck diameter of mold Take-out tongs are faulty, wrong design or material Take-out tong diameter too small Take-out tongs are not relieved correctly Neck ring worn on the parting line Shoulder radius too sharp (high shoulder bottles) Bottom plate too tight in mold recess No radius on top of mold cavity Radius of neck ring bead is too sharp   3. Mold Equipment Ensure neck diameter of mold is larger that neck diameter of blank Ensure take-out tongs have correct clearance Relieve take-out tongs Use new neck ring Check for relief on mold shoulder radius Use mold gauges to check mold equipment Ensure radius on top of mold cavity Relieve radius on neck ring head   4. Stacking Equipment Incorrect setting of tong head or gripping fingers at stacker pick-up point Wrong material or lack of insulation on tong head or gripping fingers 4. Stacking Equipment Check of correct setting of tong head or gripper fingers