Background and characteristics:
- Became commercially available in the mid 1970’s as a chemical derivative of early polyethylene materials
- Contains approximately 97.5% polyolefin polymer, 2% carbon black and .5% anti-oxidants and heat stabilizers
- Made by polymerizing ethylene gas at low temperatures to produce long linear molecular chains of carbon and hydrogen with relatively few side branches which allows the molecules to be more tightly compressed to yield a highly dense material (in contrast to low density polyethylene)
- Higher density provides greater tensilee strength, improved heat capability, higher tear resistance, increased hardness, better chemical resistance and lower water adsorption than low density polyethylene
- Very stable under buried soil conditions without any noticeable degradation over periods analyzed
- Half life is estimated to be 350 years in a buried state
- Most important characteristic is that HDPE can be easily seamed on site utilizing fusion and extrusion methods
The bottom line is the HDPE is one of the most cost effective lining materials available today.