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PBT
Material Type
Engineering Plastics
Material Full Name
Polybutylene Terephthalate
Process Compatibility
Injection Molding, CNC Machining
Basic Properties of Polybutylene Terephthalate
Property |
Parameter/Performance |
Remarks |
|---|---|---|
| Chemical Name | Polybutylene Terephthalate | Aromatic ester backbone (-Ph-COO-) |
| Molecular Structure | Semi-crystalline thermoplastic (30-45% crystallinity) | More flexible than PET |
| Density | 1.30~1.38 g/cm³ | Unfilled: 1.31 / 30% GF: 1.53 |
| Color | Natural off-white (dyeable) | Semi-transparent to opaque |
| Mechanical Properties | ||
| – Tensile Strength | 50-60 MPa (unfilled)/120-150 MPa (GF) | GF-reinforced rigidity rivals PA66 |
| – Elongation at Break | 50-300% (unfilled)/2-5% (GF) | High toughness (unfilled) |
| – Wear Resistance | μ=0.3-0.4 (unlubricated) | Better than ABS/PC, but inferior to POM |
| Thermal Properties | ||
| – HDT (1.82MPa) | 55-65℃ (unfilled)/200-210℃ (GF) | Heat-resistant grades (mineral-filled) reach 220℃ |
| – Service Temperature | -40℃~120℃ (GF short-term 150℃) | UL RTI 140℃ (electrical) |
| Chemical Properties | ||
| – Hydrolysis Resistance | Superior to PET (withstands 85℃ hot water) | GF grades tolerate boiling water |
| – Chemical Resistance | Resists oils/greases/weak acids | Vulnerable to strong alkalis/concentrated sulfuric acid |
Processing Characteristics
Drying Essential:
- 120℃ for 3-4 hours (moisture <0.02%)
- Hydrolytic degradation risk if moist
Melt Temperature:
- 240-260℃ (degrades >290℃)
Mold Temperature:
- 60-80℃ (higher temps reduce warp)
Post-Processing:
- Annealing (100℃ for 2 hours enhances crystallinity)
Common Application Areas
- Electronics: Miniature circuit breakers, motor end caps
- Automotive: Fuel system components, door lock mechanisms
- Appliances: Coffee maker tanks, iron bases
- Industrial: Gears, pump housings
Polybutylene Terephthalate Modified Types
Type |
Characteristics |
Typical Applications |
|---|---|---|
| Unfilled PBT | High toughness, easy processing | Toothbrush handles, sports gear |
| Glass-Fiber PBT | 30-50% GF, 3x higher rigidity | Automotive ignition coils, relay housings |
| Flame-Retardant PBT | UL94 V0 (Br/P-based) | Power sockets, switch components |
| PBT/PET Blend | Balanced heat resistance/flow | Headlight bases, electronic connectors |
| UV-Stabilized PBT | Carbon black/UV inhibitors | Outdoor sensor housings |
Advantages & Disadvantages
Advantages |
Disadvantages |
|---|---|
| Excellent dielectric strength (CTI 600V) | Low heat resistance (unfilled) |
| Superior fatigue resistance (>10⁵ cycles) | Notch sensitive (requires radii) |
| Fast cycle time (rapid crystallization) | Poor weatherability (needs UV stabilizers) |
Other Engineering Plastics Selection
POM Materials
PA Materials
PC Materials
PET Materials
PEEK Materials
FAQ Of PBT Materials
Visit our FAQ center for more questions.
What are the main properties of PBT plastic?
PBT offers excellent mechanical strength, heat resistance, electrical insulation, and chemical corrosion resistance, making it suitable for electronic and automotive components.
In which fields is PBT plastic commonly used?
It is often used in electronic connectors, switches, automotive light housings, and household appliance components.
What is the processing temperature range for PBT plastic?
The typical processing temperature ranges between 220°C to 250°C, depending on the material grade and processing method.