1. Feeder
  • Glass too cold
  • Gob weight is low (press and blow)
  • Incorrect gob shape
 
1. Feeder
  • Adjust temperature of the glass
  • Increase weight
  • Reshape the gob

 
2. Machine Setup and Operation
  • Insufficient settle blow time or pressure
  • Baffle holds plugged with glass
  • Improper loading, bob hanging up in delivery
  • Poor deflector alignment
  • Too low pressing pressure (press and blow)
  • Neck ring or plunger or guide ring too dirty (only press and blow)
  • Counter blow too early (blow finish away)
  • Insufficient blank swabbing and/or plunger or neck ring doping
  • Gas formation inside of the blank which does not allow the gob to enter the neck ring
  • Insufficient vacuum application time
  • Incorrect setting of baffle and funnel and respective operating arms
  • Neck ring running too hot
  • Plunger too low (press and blow operation)
  • Hot blanks-hang ups
  • New neck ring and old plungers.
  • Guide ring vacuum holes filled with glass

    Note: After blanks get worn, the neck ring radius will vary. You may need to switch equipment around to find match.

 
2. Machine Setup and Operation
  • Increase settle blow
  • Change baffle
  • Improve loading by use of better grade of spray oil or smaller deflector
  • Align deflector with center of blank mold
  • Increase pressing time and/or pressure
  • Change neck ring and plunger
  • Retard counterblow
  • Swab blanks more frequently, adjust doping spray
  • Improve venting of finish equipment
  • Increase vacuum time
  • Readjust baffle and funnel timing
  • Use neck ring cooling nozzle
  • Check if correct loading position is used
  • Reduce blank mold temperature-correct cooling and swab
  • Switch blanks around front to back

 
3. Mold Equipment
  • Insufficient venting of finish equipment
  • Dirty neck ring equipment
  • Unsuitable finish equipment (blow and blow)
  • Design of parison is unsuitable (press and blow)
  • Funnel size too small

 
3. Mold Equipment
  • Improve venting of neck ring equipment
  • Change neck ring
  • Change size of neck ring
  • Use proper blank and plunger design
  • Check funnel size