A customer asked us today: “Does your POM also have bubbles like the ones we got from another supplier?” Here’s my honest answer
What happened:An overseas customer recently sent us photos of Acetal POM-C rods and sheets they purchased elsewhere. Clear voids, visible bubbles, and uneven surfaces. Machining failures. Wasted material.
Their question to us:
👉 “Yours are the same – or different?”
So I went straight to our senior process engineer — a guy who’s run extrusion lines for over 20 years.
According to him, bubbles in Acetal POM-C usually come from four root causes:
- Moisture in raw materials – not dried properly before extrusion.
- Poor venting in the screw design – air never gets pulled out.
- Uneven cooling & internal stress – micro-voids form and later open up during machining.
- Low-grade or unstable POM resin – outgassing during melt.
- What we do differently (and have done for years):
- ✅ 4+ hours of active drying at 80°C – moisture <0.2% before extrusion.
- ✅ Venting extruders with vacuum suction – removes volatiles and trapped air.
- ✅ Continuous density monitoring – any deviation >±0.005 g/cm³ gets rejected.
- ✅ Mandatory annealing – stress-relieved, no hidden voids.
Result: Flat surfaces, no bubbles, stable machining performance — from first meter to last.
To that customer — and any engineer tired of bubble problems:
We fully support small test orders. Try our POM rods or sheets on your own CNC. Cut, drill, machine. See for yourself.
No hard sell. Just a reliable product from a factory that still believes in old‑school quality control.
👉 DM me or comment “TEST” and I’ll send you our spec sheet and small‑order details.
#POM #EngineeringPlastics #Acetal #Extrusion #QualityControl #CNCMachining #Manufacturing
