Density and Molecular Structure
- LDPE:
- Density ranges from 0.910 to 0.940 g/cm³.
- Highly branched molecular structure, resulting in lower density and better flexibility and ductility.
- HDPE:
- Density ranges from 0.941 to 0.976 g/cm³.
- Linear molecular structure with fewer branches, leading to higher density and mechanical strength.
Mechanical Properties
- LDPE:
- Lower tensile strength (approximately 8-10 MPa), suitable for applications requiring flexibility.
- Good impact resistance but lower mechanical strength and wear resistance compared to HDPE.
- HDPE:
- Higher tensile strength (approximately 25-30 MPa), ideal for applications requiring high strength and wear resistance.
- Superior impact resistance, wear resistance, and tear strength compared to LDPE.
Thermal Resistance
- LDPE:
- Poor thermal resistance, with a softening temperature around 80°C.
- Not suitable for high-temperature applications.
- HDPE:
- Higher thermal resistance, stable at temperatures up to 120°C.
- Suitable for applications involving higher temperatures.
Transparency
- LDPE:
- High transparency, commonly used in packaging applications where visibility of contents is important.
- HDPE:
- Lower transparency, typically opaque or semi-transparent.
Chemical Resistance
- LDPE:
- Good chemical resistance, though not as robust as HDPE.
- Suitable for lightweight packaging applications.
- HDPE:
- Excellent chemical resistance, resistant to acids, bases, and organic solvents.
- Ideal for chemical storage tanks and piping.
Application Areas
- LDPE:
- Packaging Materials: Food packaging bags, garbage bags, cling film.
- Agricultural Uses: Greenhouse films, mulch films.
- Electrical Applications: Insulation layers for wires and cables.
- HDPE:
- Rigid Plastic Products: Plastic buckets, pipes, bottles.
- Construction: Drainage pipes, irrigation systems.
- Consumer Goods: Toys, outdoor furniture.
Processing and Recycling
- LDPE:
- Lower processing temperature (around 160°C), with good flow properties, suitable for complex injection molding.
- Recycled LDPE is often used to produce garbage bags and agricultural films.
- HDPE:
- Higher processing temperature (around 180°C), suitable for injection molding.
- High recycling rate, with stable recycled materials used for pipes, plastic lumber, etc.
Environmental Impact
- LDPE:
- Relatively lower recycling rate, but recycled materials can be used for soft packaging and films.
- HDPE:
- Higher recycling rate, with stable recycled materials, making it a more environmentally friendly option.
Sanvera, a plastic product R & D and manufacturing company, has extensive experience in LDPE and HDPE applications. It has developed high – quality sanitary pad bottom – film packaging materials using LDPE’s flexibility and transparency, ensuring product safety and comfort. Amid growing environmental awareness, Sanvera is also committed to developing recyclable and biodegradable plastic products to reduce environmental impact and promote sustainable development in the plastic industry.
