1. Feeder
  • Glass too cold
  • Poor shear cut or too much water on shears, resulting in cold gob tip
  • Gob weight variation 
1. Feeder
  • Adjust the gob temperature
  • Change shear blades and/or reduce water on shears
  • Example the feeder to find out reason for the weight variation
  • Check for line on finish

 
2. Machine Setup and Operation
  • Plunger contact time too long resulting in cooling the finish too much
  • Too much settle blow, either pressure or time or application
  • Plunger or neck ring too cold (neck ring applies to press and blow)
  • Too much air on plunger down, for press and blow (mechanical action)
  • The two neck ring halves not aligned (mechanical action)
  • Plunger and/or plunger adaptor loose (if quick change is used)
  • Plunger locking plate loose (if plunger mech. 191-5084 is used)
  • Blow head arm incorrectly set (not aligned with mold)
  • Final blow air too early, before blow head is down
  • Internal cooling nozzle bent, touching the finish
  • Excessive plunger pressure and/or time of application, press and blow operation
  • Incorrect and excessive plunger cooling
  • Misalignment of plunger mechanism
  • Take-out tongs too cold-cover with suitable material
  • Too much finish cooling on the blow mold side
  • Baffle arm coming down too hard
  • Invert bouncing over mold during transfer
  • Plunger/thimble speed (blow and blow)
  • Candelabra could have broken spring(s) (blow and blow)

 
2. Machine Setup and Operation
  • Shorten plunger contact time
  • Reduce the settle blow pressure and/or time
  • Reduce the plunger or neck ring cooling
  • Reduce air pressure on plunger down
  • Check alignment of neck ring
  • Tighten the plunger adaptor
  • Change plunger locking plate
  • Realign blowhead arm
  • Delay final blow
  • Change internal cooling tube
  • Reduce the plunge pressing time or pressure
  • Adjust the plunger cooling
  • Realign plunger mechanism
  • Cover takeout tongs with a suitable material
  • Reduce the finish cooling over the blow mold
  • Check cushioning and speed of baffle arm
  • Check for spring and tension in neck right holder
3. Mold Equipment
  • Neck ring joints worn allowing counterblow to blow on outside of finish
  • Blow head too shallow causing contact
  • Blow head too deep, causing parison to bounce and hit the blowhead
  • Neck ring size is too large
  • Insufficient blank volume
  • Improper blank shape causing higher pressing pressure to be used (press and blow)
  • Pressing gate too small
  • Plunger tip too long

 
3. Mold Equipment
  • Change neck ring
  • Check for correct blowhead depth
  • Change to a smaller neck ring
  • Increase blank volume
  • Correct the blank shape for easier pressing
  • Increase size of pressing gate
  • Shorten plunger tip

 

Note: It causes leakage on the vacuum packed or processed foods and must be corrected at once.