TL;DR
Parts sticking in the thermoforming mold indicate insufficient air-eject pressure, too-short cooling time, or worn draft angles. Increase cooling time before increasing eject pressure.
What you might see
- parts adhere to the mold surface after eject cycle
- parts distort or stretch during ejection
- eject air pressure alarm or insufficient eject flow
- visible tearing at part rim or detail features
Likely causes
Cooling time too short, part still above the ejection temperature when eject air fires
Eject air pressure too low or air holes clogged not providing sufficient release force
Mold surface rough or contaminated with material buildup from previous runs
Draft angles in the mold worn or insufficient for the material being formed
Required tools
- IR thermometer
- Thin wire probe for air hole clearing
- Mold release agent (food-grade or resin-compatible)
- Soft cleaning cloth
Safety first
- Molds are at elevated temperature during production. Allow molds to cool before touching or use heat-resistant gloves.
- Pressurized air eject systems can cause injury if lines are disconnected while pressurized.
Procedure
- 1
Increase the cooling dwell time by 1 second increments without changing any other parameter. Test after each increment.[1]
- 2
Measure the part surface temperature at ejection with an IR thermometer. The part should be below the material heat distortion temperature before eject.[1]
- 3
Inspect the mold air eject holes for blockage with a thin wire probe. Clear any blocked holes.
- 4
Verify the eject air pressure on the control. Increase by 0.5 bar increments if the minimum cooling time is reached and parts still stick.
- 5
Inspect the mold cavity surface for material buildup or roughness. Clean with a mold release and soft cloth. Do not use abrasive pads on polished cavity surfaces.
- 6
If sticking persists after cleaning and cooling time optimization, apply a light coat of food-grade or resin-compatible mold release agent to the cavity.
- 7
Document the final cooling time and eject pressure in the job setup record for future runs.
Sources
Brown Machine Brown Aclo / Quantum Thermoformer general technical documentation, Brown Machine
Brown Machine thermoformer operator manual, ejection and cooling cycle optimization (general)
More guides for Brown Machine Brown Aclo / Quantum
How to identify and replace a failed heater element on a Brown Machine Aclo / Quantum thermoformer
A failed oven heater element creates a cold spot in the web, producing thin or incompletely formed parts in one zone. Identify the failed element with a clamp ammeter before replacing.
How to fix web sag or droop on a Brown Machine Aclo / Quantum thermoformer
Sheet sag before forming is usually the heater temperature too high, sheet tension too low, or a slow oven-to-form transfer. Lower the heater temperature in small increments and optimize the transfer time.
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