What's Unique Cold Temperature Performance
The new generation GeoFlex™ geomembrane exhibits a much higher Tensile Yield Elongation compared to standard LLDPE geomembranes. This translates into the ability of GeoFlex™ geomembranes to be far more tolerant and forgiving of “stressed” regions such as folds and bends and creases in real-life applications, resulting in the GeoFlex™ geomembranes offering far more “flexible character” under actual field use conditions. The permanent, irreversible deformation on yielding, which ultimately leads to localized thinning and cracking under stress, does not occur with GeoFlex™ until much higher elongation (strain). Secondly, the higher slope of the stress-strain curve at the higher elongation is an indicator of a much higher “Strain Hardening Modulus.” In recent years, it has been established conclusively that the magnitude of the SHM correlates very well with Slow Crack Growth/ESCR resistance. In geomembrane applications, exposure to various agents that can pose as “environmental accelerants” to these failure mechanisms.
Cold Temperature Performance
Due to the highly flexible nature of GeoFlex™, a new laboratory test, called Low-Temperature Compression Fatigue Test (LTCFT), was developed to ascertain and differentiate the flexibility performance. In this test, a typical “dog-bone” specimen is subjected to repeated compressive-fatigue (bending) for tens to hundreds of thousands of cycles until failure. The test is performed at -60 °C. Another top grade LLPDE, which was also tested, failed at 30,000 cycles due to localized thinning or yielding. Please contact Layfield for more information on this test.