Laboratory & Testing

Zebratube®’s in-house laboratory and piloting facilities allow us to test various geotextiles for our customer’s dewatering needs to ensure optimum dewatering and filtration efficiency specific to each application.

Our mobile test unit allows us to bring the Zebratube® concept to your site, proving under real time conditions our dewatering capabilities.

Each dewatering application is unique and bag sizing is very dependent on individual slurry properties.

Conducting upfront testwork has the following benefits:

  • Conformation of dewatering behaviour using our standard geotextiles under laboratory conditions.
  • Provides the necessary input parameters required to accurately size dewatering bags for your specific application.
  • The ability to test filter aids if we find geotextile-only dewatering does not prove efficient.
Types of testwork
Gravity drainage testwork

We assist our customers with laboratory-scale testwork to determine the correct geotextile for each dewatering application. Gravity drainage testwork is typically the first step, enabling us to determine the permeation rate for each geotextile as well as the filtrate quality.

Utilising a Buchner funnel together with our geotextiles, the slurry can be allowed to drain through the geotextile whilst filtrate is collected to determine the solids retention efficiency

Hanging bag trials

Hanging bag trials are used to determine the dewatering potential of a specific slurry and the dewatering efficiency of the geotextile. A small hanging geotextile bag is filled with a specific volume of slurry and allowed to dewater via gravity drainage, whilst drainage rate and filtrate clarityis monitored. 

The moisture content of the retained solids is determined after sufficient dewatering has occurred. The hanging bag can then also be left to dewater over an extended period of time to determine the long-term dewatering potential of the slurry as well as the standing time required on a full-scale project

On-site piloting

Although hanging bag trials provide a good preliminary indication of dewatering potential andgeotextile efficiency, in some cases it is imperative to scale up to pilot size with a smaller full-scale dewatering tube.

The enclosed nature of the pilot-size dewatering tube allows not only gravity to act on the slurry as in the hanging bag trials, but a slight positive pressure to develop in the tube as a result of pumping the slurry

Laboratory and Analytical Services

Our dewatering testwork services are complimented by the following analytical capabilities at our in-house laboratory:

  • Particle size distribution analysis
  • Moisture content
  • Relative density
  • Sludge permeability
Geotextile Quality Control Laboratory

In our geotextile lab strands of extruded geotextile are tested for tensile strength before being woven. Each roll of geotextile is tested for tensilte strength before being converted into dewatering bags. We also test seam strength on an ad-hoc and regular basis.

Consistent testing at our in-house laboratory ensures complete traceability and quality control

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Our in-house engineering team can assist you with custom sizing and design specific to you application

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