Woven polypropylene geotextiles

Production description: Monofilament (circular cross-section), U.V.-stabilised yarns are used for the weaving of polyethylene geotextiles

Applications: The circular cross-sectioned yarns of polyethylene give the geotextile a high percentage of open space (porosity), which produces a very high water permeability. Moreover, the inter-yarn mesh openings are of a similar size, leading to a uniform fabric construction. Filtration and drainage: Because of their uniform construction and their high permeability, woven polyethylene geotextiles are particularly suited to act as filters. It is possible to accurately determine and build in the fabric's filtration characteristics, which determine what particle sizes may flush through the geotextile and which are to be restrained. These exceptional filter characteristics are important where there is a need for highly critical and controlled performance, such as drainage behind quay walls and locks in tidal rivers where large tidal levels are experienced and where rapid drawdown can cause destabilisation of supported structures. Also woven polyethylene geotextiles are particularly suitable for use behind gabions in bank protection works on rivers and in similar situations with highly variable water levels. Tensioned river erosion toe fence: This application makes use of two narrow polyethylene geotextiles (about 0.5 m wide) which are woven together across the width at intervals of say 0.3 m. Where the toe of an embankment is suffering from water erosion, such as in a river or lake, firm wooden stakes are driven in along the toe, say every 0.8 m, so that the double textile can be slipped over the stakes to form a vertical erosion protection 'fence'. In order to work effectively, it is necessary to tension the textile before slipping it over the stakes. Tensioning is achieved by means of a hand winch and the tensioned textiles are opened for placement by means of a special hand grip device. Soil can be placed behind the fence to form a firm toe to the bank, which is resistant to high water flow rates. As an extension of this idea, the double textile can be pinned to the upper slope of the bank in a variety of ways, to prevent rain run-off erosion and to permit vegetation to grow through the open mesh of the textile.

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