What is POM Material?

1. What is POM? The Engineering Thermoplastic Revolution

POM (Polyoxymethylene), known as acetal or Delrin, delivers exceptional mechanical properties:

Near-zero moisture absorption
70 MPa tensile strength
0.2-0.3% shrinkage rate
Self-lubricating (μ=0.1-0.3 vs. steel)

Used in 78% of high-precision mechanisms requiring dimensional stability.

2. POM vs. Competing Engineering Plastics

Property	POM	Nylon 66	ABS	PEEK
Tensile Strength	70 MPa	85 MPa	40 MPa	100 MPa
Moisture Absorb.	0.2%	2.8%	1.5%	0.1%
Max Temp	100°C	120°C	80°C	250°C
Cost/kg	$3-5	$5-8	$2-4	$150-200

POM dominates in cost-sensitive precision applications, such as gears and bearings.

3. Injection Molding Processing Guide

Optimal Parameters for POM

Parameter	Standard POM	Glass-Filled POM
Melt Temp	190-210°C	200-220°C
Mold Temp	80-105°C	90-120°C
Injection Pressure	80-130 MPa	100-150 MPa
Drying (Time/Temp)	3h/110°C	4h/120°C

Critical Tip: Maintain <0.1% moisture to prevent formaldehyde gassing.

4. Solving Common POM Material Defects

Defect	Cause	BFY Mold’s Solution
Warping	Uneven cooling	Conformal cooling channels
Sink Marks	Inadequate packing	95% gate sealing pressure
Cracks	Over-crystallization	Post-mold annealing
Gas Burns	Trapped air	Vacuum venting system

5. Industry Applications & Case Studies

Automotive

Fuel system components: POM 30% GF withstands ethanol blends
Gears: 1 million+ cycles at 1500 RPM (tested per ISO 6336)

Medical

Inhaler mechanisms: USP Class VI compliant POM grades
Surgical tools: Autoclavable at 134°C

Consumer Electronics

Keyboard switches: 10M actuation lifespan
Connector housings: UL 94 HB flame rating

6. Material Selection Guide

POM Type	Key Features	Ideal Application
Homopolymer	Higher stiffness	Precision gears
Copolymer	Better chemical resist.	Fuel contact parts
30% GF	2x creep resistance	Load-bearing brackets
PTFE Blended	50% lower friction	Self-lubricating bearings

7. BFY Mold’s POM Expertise

Specialized Equipment:

Low-shear screws (L/D=22:1)
Dehumidifying dryers (less than -40°C dew point)
Quality Assurance:

ISO 9001-certified production
CMM inspection (±0.01mm)
48-hour material certification

8. About 10 Essential POM Material FAQs

1. What’s the difference between POM and Delrin?
Delrin is DuPont’s homopolymer POM; generic POM includes copolymers with better chemical resistance.

2. How to prevent POM warping?
Maintain mold temp at 90±2°C and use uniform wall thickness (1.5-3mm).

3. Can POM be bonded or welded?
Yes: Epoxy bonding (shear strength 15-20MPa) or hot-plate welding (for hermetic seals).

4. Is POM food-safe?
FDA-compliant grades exist, but they should be avoided for acidic or lipid-rich foods due to the potential release of formaldehyde.

5. What causes POM part shrinkage?
Excessive crystallinity. Solution: Increase injection speed and packing pressure.

6. Maximum continuous use temperature?
90-100°C for standard grades; 120°C for glass-filled versions.

7. How does UV affect POM?
Causes surface chalking. Use carbon-black filled grades or protective coatings.

8. Typical tolerance capabilities?
±0.05% for dimensions less than 50mm; ±0.1% for larger parts.

9. Cost comparison to metal parts?
60-80% lower cost than machined brass in high-volume production.