Preforms Jam Between the Hopper, Oven and Mould

Locate the first loss of orientation or pitch. Check preform dimensions and static, rail spacing, unscrambler speed, spindle wear, transfer timing, neck contamination and heat distortion.

Isolate high-pressure air, electrical power, heating circuits and motion energy before entering the guarded area. Treat hot oven components and pressurized blowing circuits as stored-energy hazards.

Locate the fault

• Preforms bridge in the elevator or sorter
• Necks overlap on the feed rails
• A preform drops from the heating spindle
• Jams increase with lightweight or short-neck preforms

Inspection sequence

1. Mark the first jam point before clearing downstream accumulation
2. Measure good and jammed preforms against the supplier drawing
3. Verify rail gap, slope and feed speed with the approved gauge
4. Inspect for dust, oil, static and damaged packaging
5. Inspect spindle and gripper condition under isolation; use the approved guarded test mode for any transfer-motion check
6. Compare sorter, oven and blow-wheel speed references and phase

Corrective work

• Contain out-of-tolerance or contaminated preforms
• Set rails and guides to the specified neck support
• Clean the feed system and apply only approved static-control measures
• Replace worn handling parts and restore synchronized timing

Operating records and follow-up

• Incoming-inspect critical preform dimensions
• Keep feed surfaces clean and dry
• Use dedicated changeover settings by preform
• Trend jam location and lot
• Inspect spindles and grippers before wear causes drops

Equipment details: Automatic Blow Molding Machine.