The DSC (digital scanning calorimeter) unit is quite small but is able to test the liner sheet material with great efficiency

Roediger Agencies now testing liner sheet

ROEDIGER Agencies has recently commenced the testing of geomembrane liners used in dam construction and landfill site liners. These tests have up to now been conducted in Texas or Canada but not in South Africa.

“We are now offering the full range of tests procedures according to GRI-GM 13 and 17. This involved the acquisition of a high-pressure DSC (Differential Scanning Calorimeter), of which I believe there are only two in South Africa,” said Dr Andy Roediger of the Stellenbosch-based test lab.

Most of the liner manufacturers active in SA conduct their own in-house tests on all the parameters involved to ensure quality, but additional independent testing is also required by liner users to verify specifications and integrity, which is where Roediger Agencies comes into the picture.

Liner users include specifiers and operators of landfill sites, and dam builders and construction companies, to name but a few. Users therefore no longer need to send samples to North America, so it’s a cost and time-saving option for them.

Up till now, most of the SA-made liner sheet has been tested according to the Geosynthetic Research Institute (GRI) of the USA, who publish and update the above mentioned GRI-GM Standard specifications, which is also what SA’s own SANS 1526 specification follows.

Tests conducted on both HDPE and LLDPE sheet, both smooth and textured geo-membranes, include thickness (0.5-3mm); formulated density; modulus; tear and puncture resistance; axi-symmetric break strain; carbon black content and dispersion; oxidative induction time; oven ageing and UV resistance test procedures.

Tests on liner sheet are especially important as, once installed in a dam or landfill site, failure of the sheet could create significant complications.

Roediger Agencies, which celebrated its 30th year in operation last year, conducts a comprehensive range of tests on a range of plastic materials and products. It has lab equipment for virtually every test required, with the new DSC unit almost rounding off its lab arsenal.

It uses gas chromatograph, liquid chromatograph (both used for the testing of additives); a calorimeter for thermomechanical analysis (for tests of inorganic fillers in polymers); thermal gravimetric analyser; differential scanning calorimeter, weatherometer and even more. It can test for polymer identification, melt flow, impact, Charpy, Vicat, UV stabilization, light stabilization, age degradation and more, with Dr Roediger proving adept at selecting systems and travelling extensively to purchase apparatus.