PP (Polypropylene) vs PE (Polyethylene): Key Differences, Properties, and Applications
Last updated : 2026/7/24
Key Takeaways
PP and PE are lightweight, chemically resistant plastics with excellent moldability, electrical insulation, and low moisture absorption.
PP is stronger, stiffer, and more heat-resistant, while PE is softer, more flexible, and offers better weather and impact resistance.
Material selection depends on the application—PP is ideal for rigid structural parts, while PE is better suited for films, pipes, and flexible components.
Overview
Polypropylene (PP) and polyethylene (PE) are two of the most widely used plastics worldwide. Made from carbon and hydrogen, both are lightweight and versatile, supporting a range of processing methods such as molding and machining. From grocery bags to food containers, they are among the most common plastics found in daily life.
Polypropylene (PP): A lightweight resin (specific gravity 0.90) known for its strength, scratch resistance, and excellent chemical durability.
Polyethylene (PE): A lightweight resin (specific gravity 0.95) with low water absorption, strong dimensional stability, and high resistance to both chemicals and impact.
Common Characteristics
Composed of carbon and hydrogen polymers.
Excellent moldability, making them ideal for cost-efficient mass production.
Low heat resistance, making them unsuitable for high-temperature applications.
Classified as flammable and combustible materials.
Lightweight, with a specific gravity less than 1.
Strong electrical insulation properties.
Low dielectric constant (used in high-frequency applications and safe for microwave use without generating heat).
Low water absorption, ensuring dimensional stability.
Tasteless, odorless, and non-toxic.
Key Differences
While similar, PP and PE have distinct differences.
Property | Polypropylene (PP) | Polyethylene (PE) |
|---|---|---|
Melting Point | Higher | Lower |
Heat Deflection Temperature | 60–65 °C | 30–50 °C |
Continuous Service Temperature | ~65 °C (electrical use) | ~50 °C (electrical use) |
Hardness & Flexibility | Harder, more rigid | Softer, more flexible |
Appearance | Translucent to white | Opaque white |
Weather Resistance | Moderate | Superior |
Typical Applications of PP and PE
Each material is suited to different uses based on its properties:
Polyethylene (PE): Soft films and sheets, water pipes, gas pipes.
Polypropylene (PP): Fibers, nonwoven fabrics, rigid sheets, structural components, adhesive tapes, rigid foams.
PP & PE CNC Machining at Yumoto Electric
Yumoto Electric delivers high-quality components fast, worldwide. We provide precision machining for a wide range of engineering plastics, including PEEK, PPS, MC Nylon, and POM.
If you’re unsure about material selection or machining methods, we offer complimentary consultations to help optimize your design and production. For any questions, please feel free to contact us.
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