HDPE or PVC As A Liner- Which is better?
Question: Which is the better choice when it comes to HDPE or PVC for use as a liner?
Answer: This is quite a question that I believe could be argued both ways. The one factor that tips the scales in the favor of HDPE (in my opinion) is the negative effect PVC has on the environment. PVC and its disposal poses substantial environmental and human health hazards. In fact in European nations, certain uses of PVC have been eliminated for environmental reasons. When PVC is produced, it releases toxic by-products during its creation. Large quantities of hazardous organochlorine by-products are formed and released into the environment. Components of PVC can affect feed-stock and build up in the tissue of living things.
As far as PVC liners go- they are used because it is a highly flexible, cost-effective waterproofing geomembrane. Its flexibility comes from the addition of a large amount of plasticisers- usually phthalates at concentrations of 30-50%. These phthalates may have carcinogenic properties or affect endocrinic activities. It is highly flexible and readily conforms to the surface it comes in contact with. It has excellent corrosion resistance and weather resistance. It is not UV stabilized however. If PVC is burned it produces toxic byproducts such as dioxins, chlorocrbons and hydrochloric acid.
HDPE is respected because it is a very strong, long lasting liner that can be recycled. It has high chemical resistant qualities that protect the environment from toxic spills when used in that capacity. It is cost effective, and perhaps the most cost effective liner for large projects. HDPE comes in a wide range of thicknesses and sizes. It has high impact strength and good water vapor and alcohol barrier properties. Additionally it has good stress crack and impact resistance. It can withstand higher temperatures than some of its cousins.
