Engineering polyethylene geomembrane performance depends on resin, additive package and process control. Colour, hand feel and a short tensile test cannot establish long-term suitability.
Equal thickness does not mean equal material
Polymer molecular structure, contamination and blend stability affect low-temperature behaviour, welding, stress cracking and ageing.
Build an evidence chain
Specify density, mechanical properties, carbon black, oxidative induction time and stress-crack resistance where required by the adopted standard. Verify test methods and lot identity.
Use field welding as an additional control
Daily trial seams establish site parameters and may reveal inconsistent melt behaviour. They do not replace batch qualification or resin controls.
Project action list
What the procurement or project team should do next
Do not compare offers by thickness alone
Request complete lot test data
Retain roll IDs with sampled material
Define nonconformance disposition in the contract
References