Géomembrane HDPE VS LLDPE
Brief
When selecting a geomembrane, we should choose the most suitable geomembrane for the applications. Here, we will have a deep sight into the advantages and disadvantages of the two most common geomembranes, High-Density Polyethylene (HDPE) and Linear Low-Density Polyethylene (LLDPE).
1. Density
High-density polyethylene (HDPE) geomembrane is defined by a density greater than 0.941 g/cm3.
Low-density polyethylene (LLDPE) geomembrane is defined by a density range of 0.915–0.925 g/cm3.
2. Chemical Structure
HDPE geomembrane has high tensile strength.
LLDPE geomembrane has the characteristics of toughness and flexibility.
3. Heat Resistance
HDPE geomembrane can withstand temperatures above 100 degrees Celsius, whereas LLDPE decreases in density at temperatures above 20 degrees because it has the lowest heat resistance.
4. Chemical Resistance
LLDPE and HDPE geomembrane is resistant to most solvents, alcohols, acids, and alkalis but have a low resistance to most hydrocarbons.
5. Melting Points
HDPE is easy to injection mold and its melting point varies between 110:135 degrees Celsius, compared to 122 degrees Celsius for LLDPE.
6. Flexibility
HDPE geomembrane is more rigid and less resilient to the environment. It lacks flexibility and can lead to damage when folded on its own. Compared to HDPE, LLDPE geomembrane is more flexible, easier to stretch, and more adaptable to the environment. It won’t be damaged by being folded up.
7. Weather And UV Resistant
HDPE geomembrane performs best in this respect. It can withstand the daily battering from the sun and the elements. However, the life span of the LLDPE geomembrane can be extended by adding additional additives in the manufacturing process.
8. Permeability
HDPE geomembrane is less permeable than LLDPE, in other words, it is indispensable for applications where a sealing liner is required as a strong chemical barrier, such as landfill base liners.
9. Strength
HDPE geomembrane is the strongest, but remember that it is more prone to stress cracking and inflexibility. LLDPE geomembrane is quite flexible and is unlikely to suffer from stress cracking.
10. Applications
Where chemicals are involved, you need the chemically resistant polymer HDPE geomembrane.
Where the material needs to be subjected to constant pressure, LLDPE geomembrane would be a better choice than HDPE.
For projects that require a durable product, the HDPE geomembrane may be your best choice.
Easy to install and not requiring the same strength as HDPE geomembrane, LLDPE may be a better choice.
