THE POLYETHYLENES
Polyethylene is the most common type of consumer plastic and appears in everyday materials, from food packaging to bulletproof vests. The same properties that make polyethylene ideal for these uses make it an ideal liner for your pond, so it's not surprising that most new pond liner options available are some form of polyethylene.
- Polyethylene is so resistant to water absorption and chemical damage that it's often certified as food safe. Each product in BTL's AquaArmor line is certified NSF-61, which designates it as suitable for storing drinking water. It is superior to other materials that can leach dangerous chemicals into your pond and harm or kill both plants and fish.
- Polyethylene fibers are robust yet lightweight, which makes them an ideal material for bulletproof vests. That same resistance to punctures and tears makes woven (reinforced) polyethylene products like BTL's AquaArmor and ArmorPro lines very reliable.
- Polyethylene is remarkably durable - it retains its properties in the depths of winter but can be heat-welded for an exceptionally tight seam. Polyethylene may become brittle when exposed to direct sun over time but added UV stabilizers can eliminate this issue.
HDPE (High Density Polyethylene)
HDPE is historically one of the most popular geomembrane options in the world. It's a woven material that is chosen primarily for its density. Unfortunately, this density makes it slightly stiff or rigid, making it more difficult to pack, ship, and install than superior choices such as RPE. Its rigidity also makes it more prone to folds and wrinkles.
HDPE does share many of the advantages of other polyethylenes, including chemical resistance and a functional lifespan of 30 years or more.
LDPE (Low Density Polyethylene)
LDPE shares some of the characteristics of HDPE, both good and bad. It's relatively cheap, fish-safe, weldable, and performs well in cold temperatures.
LDPE's main advantage over HDPE is that it's softer, more flexible, and more pliable than the denser HDPE. These qualities make it easier to fold, easier to install, and more forgiving of rough terrain. On the downside, LDPE has less tensile strength than HDPE, meaning it can tear or stretch out of shape. LDPE isn't quite as resistant to UV rays and oxidation either, so it may not last as long unless carefully protected from any weathering effects.
RPE (Reinforced Polyethylene)
RPE's outstanding feature is its multilayer construction. A woven, reinforcing core provides exceptional toughness and resistance to punctures, while outer layers offer flexibility, additional toughness, UV protection, and other specialized protections. Amazingly, the combination combines the best attributes of HDPE and LDPE without the downsides of either product.
The unique construction of RPE makes BTL's AquaArmor liners by far the most durable of all pond liner materials available. It rarely requires underlayment, yet an RPE liner is half the thickness of liners such as EPDM and PVC for the same application. The material's outstanding qualities mean that RPE is only one-third the weight, even compared to other polyethylene products, making it easy to fabricate giant liners that are far less expensive to ship and easier to install.
RPE's only real downfall is its price. It's more expensive than HDPE or LDPE due to its complex construction. Still, the significant advantages of RPE over other polyethylenes and other plastic products make it more durable, more installable, and more functional over time. When considered overall, the long-term cost of an RPE liner is superior to the short-term savings of cheaper options.
