When installing HDPE geomembranes for high-risk containment systems, such as mining leach pads, waste sites, water reservoirs and agricultural dams, there is zero room for error.

A single leak or a weak seam can have a severe impact on the environment and lead to costly contamination, penalties and even structural failure.

As an expert in HDPE liners, Gundle Geosynthetics knows the consequences and cost of compromising on quality.

Their comprehensive Quality Control (QC) plan incorporates ISO 9001:2015 standards and Geosynthetic Research Institute (GRI) specifications, ensuring that every lining system is installed in accordance with international standards.

To ensure the long-term durability and containment security of their installations, Gundle Geosynthetics’ quality control process relies on three things.

Strict adherence to ASTM standards, rigorous field testing and qualified and certified welding technicians.

Gundle Geo’s team ensures that every seam is perfectly sealed.

The global benchmark

First off, their quality begins with the global benchmark, adhering to ASTM standards.

ASTM International standards specify the precise testing methods, material tolerances and performance criteria that geosynthetic materials must meet.

By applying these ASTM guidelines, Gundle ensures that the raw materials and installed liners meet necessary mechanical and chemical requirements. These global benchmarks also align with local regulations, such as SANS 10409 and SANS 1526, which guarantee that Gundle Geo’s solutions are reliable even under harsh environmental conditions over a decade of service life.

Destructive and non-destructive testing

To ensure these benchmarks are met, Gundle Geosynthetics puts their products and installations through both destructive and non-destructive testing. These tests are used to verify field seam integrity.

Destructive testing verifies mechanical strength: Destructive testing physically stresses the material until it fails, using tensiometers. By evaluating peel and shear resistance on daily trial seams and periodic field cuts, destructive testing verifies that the weld has achieved a good molecular bond and has resulted in a film-tear bond, which means the HDPE material tears before the seam itself comes loose.

Non-destructive testing guarantees 100% watertightness: While destructive testing is sample-based, non-destructive testing checks 100% of the installed field seams without damaging the liner. By using dual-track air-pressure testing on hot-wedge welds, combined with a vacuum box and high-voltage spark testing on extrusion welds and patches, non-destructive testing pinpoints microscopic pinholes, voids or cold spots before the projects are handed over to the client.

The combination of destructive and non-destructive testing proves that the seam will not pull apart under mechanical stress and guarantees that no fluid can escape the entire containment area.

Certified welders must delicately balance heat, speed and pressure to achieve a good weld.

Precision in the field

Advanced material testing and strict standards can only be as effective as the technicians who apply them.

Polyethylene welding requires a welder to delicately manage heat, pressure and speed to achieve a perfect, lasting bond. These factors are heavily influenced by ambient temperature, wind and humidity. That is why an experienced welder is needed to get the job done correctly.

Gundle Geo deploys fully certified, highly trained thermal welding technicians who excel in both double-hot-wedge and extrusion fillet welding. These welders are specialists in their field and understand how to adjust equipment settings to suit field conditions, perform mandatory pre-shift trial welds, and execute rigorous quality assessments and quality logging.

It is these welders’ expertise that ensures that every joint achieves maximum strength, full regulatory compliance and total peace of mind for clients.

At Gundle Geosynthetics, quality is not merely a protocol, it is a promise to protect your investment and the environment.

Contact Gundle Geosynthetics today or visit their website at https://www.gundlegeo.co.za/ to learn more about the quality they deliver.