Benefits of HDPE Geomembranes
HDPE geomembranes provide a number of benefits for lining dams, reservoirs and canals. The liners are UV stable, durable and can be cost efficient.
The blending, compounding and mixing stages are usually done on a weight or percentage basis. Regrind, rework and trim material are often added to the formulation on a regular basis as a cost efficiency measure by manufacturers.
High Density
High density polyethylene geomembrane is the most common type of geomembrane used in a variety of environmental projects. It is resistant to attack and degradation by almost all chemicals making it the preferred choice for landfills, pond liners, sewage treatment plants, anaerobic digesters and other SUDS (Sustainable Urban Drainage System) applications.
It is also very durable and tough, resisting a wide range of temperatures. It is available with a smooth or textured surface and in various thicknesses.
The manufacturing process for HDPE involves mixing polymer resin, fillers, additives and carbon black to create the formulation. This is then pressure fed into a die that forms the material into sheets that are cut to size for specific applications.
Generally, a coextruded textured HDPE geomembrane will have a white or other light colored surface layer on a black base layer. This is used when the liner will be exposed to sunlight for an HDPE geomembrane extended period of time. The surface layer will help reduce the amount of UV exposure the geomembrane experiences. It can also be used to help with the visual appearance of a lined pond or landfill.
High Durability
HDPE geomembranes are highly resistant to UV, chemicals and tearing. They are used in a wide range of projects including waste containment, landfills and mining. The material is also non-toxic and environmentally friendly. These features make it an ideal liner for landfills and waste containment projects.
The manufacturing process of a geomembrane is very important and requires strict quality control procedures to ensure a high-quality product. The polymer resin is blended with additives and pressure fed into a die that forms it into sheets of different sizes. The sheets are then cut to fit the specific dimensions of the pond, mine or landfill.
Many different tests are performed to evaluate the durability of a geomembrane, such as tensile and tear test, oxidative induction time test, stress cracking test and melt flow index test. The oxidative induction time test measures the degradation of the HDPE geomembrane due to free chloride solution penetration. One study found that exposure to sunlight over a 10-year period had little impact on the majority of the materials properties, making them nearly indistinguishable from a freshly manufactured sample.
Low Density
With the world’s population growing exponentially, there are a multitude of infrastructure projects in the making. These projects require effective protection against water infiltration and hazardous waste containment solutions that deliver reliable long-term performance at lower operating costs compared to traditional concrete lining systems.
HDPE geomembranes are manufactured by combining polymer resins, fillers, carbon black and additives to create what’s known as the “formulation.” The formulation is then processed into sheets of various widths and thickness through extrusion, calendering or spread coating methods.
The spread coating method produces geomembranes that are multiple-ply reinforced materials and therefore require the use of MQC and MQA plans and specifications. This process is used for textured HDPE and LLDPE geomembranes produced by co-extrusion.
Depending on the project and environmental conditions, different geomembrane types will be appropriate for your engineering needs. Understanding the differences between these geosynthetic materials can help you make an informed decision to protect your next project from the ingress of water, radon, gases, and chemicals. Choosing the right material will prevent costly mistakes and protect your investment over time.
Low Water Absorption
The waterproofing capability of HDPE geomembrane is a crucial aspect for many industrial projects that require water, liquids or vapor to be contained. These membranes are used where loss of materials cannot be allowed – whether it is clean water, wastewater or even hazardous chemicals or solid waste.
These liner materials are very popular because of their versatility. They are used geomembrane in a variety of applications including landfills, mining waste rafts, water treatment plants and construction projects.
Besides being an effective waterproofing material, HDPE geomembrane has good tensile properties and is resistant to cold and hot weather. This can help ensure a long lifespan for the material.
There are different types of geomembranes on the market, but each has its own specific characteristics. It is important that the right type of geomembrane be selected for each project to ensure that it performs well and is durable over time. To do this, experts must consider the geological conditions and other environmental considerations. They must also look at the material and thickness of the liner. In addition, they must check the chemical stability of the membrane.
Low Chemical Absorption
The low chemical absorption of HDPE geomembrane makes it ideal for landfill liners and other environmental projects dealing with liquid waste containment. For example, a municipal waste landfill liner needs to protect against organic acids within the leachate and stresses from excavation operations and UV radiation.
The material also provides unsurpassed chemical resistance in soils with high levels of soluble salts and other toxic chemicals that are commonly found in the soil and groundwater of waste sites.
HDPE geomembranes are manufactured by extruding a thick, flexible polymer sheet into its desired shape and adding carbon black, antioxidant, and a high-temperature stabilizer. The membrane is then cut to size and prefabricated in sections to be welded together on site during installation.
A coextruded surface layer can be added to the HDPE geomembrane to make it more durable, resistant to punctures, and easier to work with. This can be done by using a textured extruder that creates bumps or grooves on the surface of the liner to increase friction between the liner and the surrounding soil.
