What kind of engineering plastic you need to choose ?

Normally when we start a project, want to use the plastic parts ?

but don't know what kind of engineering plastic we need to choose.

Here are some properties for common engineering plastic, such as PA , PC , POM , PBT , PPO , PTFE , PEEK , ABS etc.

 

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1. Polyamide (PA, Nylon)

 

• Overview: Wear-resistant, high strength, oil-resistant. Common types include PA6, PA66, PA12.

• Advantages:

  • High mechanical strength, resistant to impact and fatigue.

  • Good resistance to oils and chemicals.

• Disadvantages:

  • High hygroscopicity (absorbs moisture), leading to poor dimensional stability.

  • Softens at high temperatures (long-term use: ~80–120°C).

• Applications: Gears, bearings, automotive components (e.g., radiator tanks), industrial ropes.

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2. Polycarbonate (PC)

 

• Overview: Transparent, impact-resistant, excellent optical properties.

• Advantages:

  • High light transmittance (similar to glass), 200x more impact-resistant than glass.

  • Wide temperature range (-60°C to 130°C).

• Disadvantages:

  • Poor resistance to strong alkalis and organic solvents; prone to stress cracking.

  • Surface scratches easily.

• Applications: Bulletproof glass, safety helmets, electronic device housings (e.g., phone cases), medical equipment.

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3. Polyoxymethylene (POM )

 

• Overview: High rigidity, low friction coefficient, self-lubricating.

• Advantages:

  • Excellent dimensional stability and fatigue resistance.

  • Resistant to organic solvents and oils.

• Disadvantages:

  • Poor resistance to strong acids and UV light.

  • Releases formaldehyde gas when burned.

• Applications: Precision gears, sliding parts (e.g., zippers), automotive fuel system components.

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4. Polybutylene Terephthalate (PBT)

 

• Overview: Heat-resistant, excellent electrical insulation. Often used in electronics.

• Advantages:

  • High-temperature resistance (long-term use: ~120°C).

  • Low moisture absorption and dimensional stability.

• Disadvantages:

  • Poor resistance to strong acids/bases; low toughness.

  • Susceptible to hydrolysis in hot water.

• Applications: Connectors, switches, automotive sensors, appliance housings.

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5. Polyphenylene Oxide (PPO/PPE)

 

• Overview: Heat-resistant, dimensionally stable. Often blended with PS for modification.

• Advantages:

  • Low moisture absorption, excellent electrical properties.

  • Resistant to hydrolysis and high-temperature steam (long-term use above 100°C).

• Disadvantages:

  • Difficult to process (requires high-temperature molding).

  • Poor UV resistance.

• Applications: Medical devices, hot water pipes, automotive dashboards.

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6. Polytetrafluoroethylene (PTFE )

 

• Overview: Extreme chemical resistance; one of the lowest friction coefficients.

• Advantages:

  • Resistant to strong acids/bases; wide temperature range (-200°C to 260°C).

  • Exceptional self-lubrication.

• Disadvantages:

  • Low mechanical strength; prone to cold flow deformation.

  • Difficult processing (requires sintering).

• Applications: Non-stick cookware coatings, chemical pipe linings, seals.

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7. Polyether Ether Ketone (PEEK)

 

• Overview: High-performance specialty plastic; heat- and radiation-resistant.

• Advantages:

  • Long-term heat resistance (260°C); strong chemical resistance.

  • Mechanical properties comparable to metals.

• Disadvantages:

  • Extremely high cost (10x+ more than standard engineering plastics).

  • Demanding processing conditions.

• Applications: Aerospace components, medical implants, oil drilling equipment.

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8. Acrylonitrile Butadiene Styrene (ABS)

• Overview: Balanced properties, easy to process; surface can be plated.

• Advantages:

  • High toughness, good low-temperature performance.

  • Easy to mold into complex shapes via injection.

• Disadvantages:

  • Poor weather resistance (yellows easily); weak against organic solvents.

  • Low heat resistance (~80°C).

• Applications: LEGO bricks, automotive interiors, appliance housings.

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Comparison Summary

Material	Temperature Resistance	Strength	Key Weaknesses	Typical Applications
PA	Moderate (~120°C)	High	Hygroscopic, dimensional shift	Gears, bearings
PC	Moderate (~130°C)	High	Stress cracking	Safety lenses, housings
POM	Moderate (~100°C)	High	Weak acid resistance	Precision parts, sliders
PBT	Moderate (~120°C)	Medium	Brittleness	Electrical connectors
PPO	High (~150°C)	Medium	Processing difficulty	High-temperature parts
PTFE	High (~260°C)	Low	Low strength	Seals, non-stick coatings
PEEK	Extreme (~260°C)	Very High	Extreme cost	Aerospace, medical implants
ABS	Low (~80°C)	Medium	Poor UV resistance	Housings, toys

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Material Selection Tips

 

• High temperature/chemical resistance: Prioritize PEEK or PTFE.

• High-precision parts: POM or PA (with humidity control).

• Transparent and impact-resistant: PC.

• Low cost and easy processing: ABS or PBT.

 

Let me know if you need further details!