Overview
PET (Polyethylene Terephthalate) is a high-performance thermoplastic polyester known for its excellent strength, dimensional stability, chemical resistance, wear resistance, transparency, and food-contact safety.
PET combines the mechanical properties of engineering plastics with the processing advantages of commodity polymers. It is widely used in both industrial applications and consumer products, including packaging, electrical components, and precision-machined parts.
PET is widely used in:
- Beverage Bottles
- Food Packaging
- Electrical Insulators
- Precision Mechanical Components
- Bearings and Bushings
- Medical Packaging
- Automotive Components
- Industrial Machinery Parts
Due to its excellent balance of mechanical strength, moisture resistance, and cost-effectiveness, PET is one of the most widely produced plastics globally.
Material Specification
| Property | Value |
|---|---|
| Material Designation | PET |
| Full Name | Polyethylene Terephthalate |
| Common Names | PET, PETP, Polyester |
| Material Family | Thermoplastic Polyester |
| Density | 1.34–1.40 g/cm³ |
| Appearance | Transparent, White, Black, Colored |
| Typical Manufacturing Methods | Injection Molding, Extrusion, Blow Molding, CNC Machining |
| Standard Forms | Sheet, Rod, Film, Pellets |
Chemical Composition
PET is produced through polymerization of ethylene glycol and terephthalic acid.
| Component | Function |
|---|---|
| Polyethylene Terephthalate Polymer | Structural Matrix |
| Stabilizers | Thermal Stability |
| Nucleating Agents (Optional) | Crystallization Control |
| Colorants | Appearance Enhancement |
PET is available in both amorphous and semi-crystalline forms.
Common PET Grades
| Grade | Characteristics |
|---|---|
| PET-A | Amorphous, Transparent |
| PET-C | Crystalline, High Strength |
| Glass Filled PET | Enhanced Stiffness |
| Food Grade PET | FDA-Compliant |
| Reinforced PET | Improved Structural Performance |
Mechanical Properties
Typical Values
| Property | Value |
|---|---|
| Tensile Strength | 55–80 MPa |
| Yield Strength | 50–75 MPa |
| Elongation at Break | 20–150% |
| Flexural Strength | 80–120 MPa |
| Flexural Modulus | 2.0–3.0 GPa |
| Hardness | Rockwell M85–105 |
| Compressive Strength | 80–120 MPa |
Typical Mechanical Performance
| Property | Performance |
|---|---|
| Strength | Excellent |
| Stiffness | Excellent |
| Wear Resistance | Good |
| Dimensional Stability | Excellent |
PET offers excellent mechanical performance compared with many commodity plastics.
Physical Properties
| Property | Value |
|---|---|
| Density | 1.34–1.40 g/cm³ |
| Water Absorption | 0.1–0.4% |
| Thermal Conductivity | 0.20–0.30 W/m·K |
| Electrical Resistivity | >10¹⁴ Ω·cm |
| Refractive Index | 1.57 |
| Specific Heat Capacity | 1200 J/kg·K |
PET exhibits excellent moisture resistance and dimensional stability.
Thermal Properties
| Property | Value |
|---|---|
| Melting Point | 245–265°C |
| Glass Transition Temperature | 70–80°C |
| Heat Deflection Temperature | 70–85°C |
| Continuous Service Temperature | -40°C to 110°C |
| Short-Term Service Temperature | Up to 150°C |
PET provides significantly higher temperature resistance than PE and PP.
Strength-to-Weight Ratio
| Material | Density (g/cm³) | Tensile Strength |
|---|---|---|
| PET | 1.38 | 70 MPa |
| PP | 0.90 | 35 MPa |
| HDPE | 0.95 | 30 MPa |
| Aluminum 6061 | 2.70 | 310 MPa |
PET offers excellent structural performance while remaining lightweight.
Chemical Resistance
| Chemical Environment | Performance |
|---|---|
| Water | Excellent |
| Dilute Acids | Excellent |
| Dilute Alkalis | Good |
| Alcohols | Excellent |
| Oils & Greases | Excellent |
| Hydrocarbons | Good |
| Organic Solvents | Moderate |
| Strong Alkalis | Poor |
PET provides excellent resistance to moisture, oils, and many industrial chemicals.
Moisture Resistance
| Property | Performance |
|---|---|
| Water Absorption | Low |
| Humidity Resistance | Excellent |
| Dimensional Stability | Excellent |
| Corrosion Resistance | Excellent |
PET maintains stable dimensions even in humid environments.
Electrical Properties
| Property | Value |
|---|---|
| Volume Resistivity | >10¹⁴ Ω·cm |
| Surface Resistivity | >10¹³ Ω |
| Dielectric Strength | 15–25 kV/mm |
| Dielectric Constant | 3.0–3.5 |
PET is commonly used in electrical insulation and electronic components.
Wear Resistance
| Property | Performance |
|---|---|
| Abrasion Resistance | Good |
| Sliding Wear Resistance | Good |
| Surface Durability | Good |
| Friction Characteristics | Moderate |
PET performs well in moderate wear applications.
Machinability
| Process | Rating |
|---|---|
| CNC Milling | Excellent |
| CNC Turning | Excellent |
| Drilling | Excellent |
| Routing | Excellent |
| Laser Cutting | Good |
Machinability Comparison
| Material | Machinability |
|---|---|
| PET-C | Excellent |
| POM | Outstanding |
| Nylon | Excellent |
| PC | Good |
PET-C is widely used for precision-machined industrial components.
Injection Molding Characteristics
| Property | Rating |
|---|---|
| Moldability | Excellent |
| Flow Characteristics | Good |
| Production Efficiency | Excellent |
| Surface Finish | Excellent |
| Dimensional Accuracy | Excellent |
PET is widely used for both packaging and engineering components.
International Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ISO | PET |
| ASTM | Polyethylene Terephthalate |
| DIN | PETP |
| JIS | PET |
| GB/T (China) | 聚对苯二甲酸乙二醇酯（PET） |
| FDA | Food Grade PET Available |
Available Forms
| Product Type | Availability |
|---|---|
| Sheet | Yes |
| Rod | Yes |
| Film | Yes |
| Pellets | Yes |
| Blow Molded Parts | Yes |
| Injection Molded Parts | Yes |
Typical Applications
Packaging Industry
- Beverage Bottles
- Food Containers
- Cosmetic Packaging
- Pharmaceutical Packaging
Electrical Industry
- Insulators
- Connectors
- Coil Bobbins
- Electrical Housings
Industrial Equipment
- Bearings
- Bushings
- Wear Pads
- Structural Components
Automotive Industry
- Sensor Housings
- Electrical Components
- Under-Hood Parts
Medical Industry
- Sterile Packaging
- Medical Containers
- Laboratory Components
Consumer Products
- Transparent Containers
- Appliance Components
- Sporting Goods
Manufacturing Characteristics
| Manufacturing Process | Rating |
|---|---|
| Injection Molding | Excellent |
| Blow Molding | Outstanding |
| Extrusion | Excellent |
| CNC Machining | Excellent |
| Thermoforming | Good |
Advantages
Excellent Strength
Higher tensile strength than PE and PP.
Outstanding Dimensional Stability
Suitable for precision engineering applications.
Good Wear Resistance
Performs well in mechanical components.
Excellent Moisture Resistance
Low water absorption improves dimensional accuracy.
Food Contact Safe
Widely used in food and beverage packaging.
Recyclable
One of the most recycled plastics worldwide.
Limitations
Sensitive to Strong Alkalis
Can degrade in highly alkaline environments.
Moderate Impact Resistance
Less impact resistant than Polycarbonate.
Moisture Control Required During Processing
Proper drying is necessary before molding.
UV Stability
Outdoor applications may require UV-stabilized grades.
Comparison with Common Plastics
| Property | PET | PP | HDPE | POM |
|---|---|---|---|---|
| Strength | Excellent | Good | Moderate | Excellent |
| Chemical Resistance | Good | Excellent | Excellent | Good |
| Dimensional Stability | Excellent | Good | Good | Excellent |
| Wear Resistance | Good | Moderate | Moderate | Excellent |
| Heat Resistance | Better | Good | Moderate | Good |
Comparison with POM
| Property | PET-C | POM-C |
|---|---|---|
| Strength | Similar | Similar |
| Wear Resistance | Good | Better |
| Moisture Resistance | Excellent | Excellent |
| Chemical Resistance | Good | Better |
| Cost | Lower | Higher |
Available Surface Finishes
Standard Finishes
- Natural Finish
- Gloss Finish
- Transparent Finish
Functional Finishes
- CNC Machined Finish
- Polished Finish
- Molded Finish
Specialty Grades
- PET-A
- PET-C
- Glass Filled PET
- Food Grade PET
- Reinforced PET
Frequently Asked Questions (FAQ)
What is PET?
PET (Polyethylene Terephthalate) is a thermoplastic polyester known for high strength, dimensional stability, transparency, and food-contact safety.
What is PET used for?
Typical applications include:
- Beverage Bottles
- Food Packaging
- Bearings
- Electrical Components
- Industrial Machinery Parts
Is PET food safe?
Yes. Food-grade PET is widely used for beverage and food packaging worldwide.
Is PET chemically resistant?
Yes. PET provides excellent resistance to water, oils, alcohols, and many chemicals.
Can PET be machined?
Yes. PET-C is widely used for CNC machining and precision engineering applications.
Why choose PET?
Because it combines:
- Excellent Strength
- Dimensional Stability
- Moisture Resistance
- Food Safety
- Cost Efficiency
What is the difference between PET and PET-C?
PET-C is a crystalline engineering grade offering higher strength, stiffness, and machinability than amorphous PET.
Does GCNOV provide PET manufacturing services?
Yes. GCNOV provides:
- PET CNC Machining
- PET Injection Molding
- Blow Molding
- Food Packaging Manufacturing
- Prototype Development
- Low-Volume Production
- Mass Production
- Precision Engineering Components