Development of an iron-ochre clogging-resistant filter complying to the European Market Requirements

地下排水主要是降低土体中的地下水位。这一功能对于保护建筑物等人造结构免受水分产生的霉菌的影响至关重要;防止道路承载力的损失;以及从农业土壤剖面中去除多余的水分，为作物生产提供合适的条件。地下排水管道必须保持畅通，以便水流动。除了管道的水力能力之外，这种结构的设计和维护主要集中在借助过滤器将土壤颗粒保持在核心之外，并避免被树根或铁赭石堵塞。在北美，实现过滤功能通常使用土工织物过滤器，特别是针织土工织物。然而，欧洲采用了一种不同的技术：在地下排水应用中使用的欧洲管道通常包裹在一束厚厚的纤维中，由一个非常开放的网格固定在一起，而不是管状编织物。用针织土工布代替欧洲目前使用的纤维束作为管道包裹物是一种具有成本效益的解决方案。然而，这种技术的采用受到不同问题的限制，包括非常保守的商业环境，因为担心针织土工布比纤维束对铁赭石堵塞更敏感。为了在欧洲市场上推出针织土工布，产品必须满足特定的需求，这些需求与工业合作伙伴目前服务的市场无关。首先，产品必须根据欧洲标准定义，并考虑欧洲的关注点，特别是关于特征开口尺寸的确定。第二，该产品应提供增强的抵抗铁赭石形成。

Subsurface drainage essentially consists in lowering the water table in a soil mass. This function is critical to protect man-made structures such as buildings against moisture-generated mold; to prevent losses of bearing capacity of roadways; as well as to remove excess moisture from the soil profile in agriculture, providing suitable conditions for crop production. Subsurface drainage pipes must remain open for water to flow. Beside the hydraulic capacity of the pipe, the design and maintenance of such structures focuses mainly on maintaining soil particles out of the core with the help of a filter, and avoiding clogging by roots or iron ochre. Achieving the filtration function is typically done using a geotextile filter in North America, and in particular knitted geotextiles. However, a different technology is used in Europe: instead of tubular knits, European pipes used in subsurface drainage applications are typically wrapped in a thick bundle of fibres, held together by a very open mesh.Replacing the fiber bundle currently used in Europe as a pipe-wrap by a knitted geotextile is a cost-effective solution. However, adoption of this technology is restrained by different issues, including a very conservative business environment reinforced by the fear that the knitted geotextile is more sensitive to iron-ochre clogging than a bundle of fibers. To introduce knitted geotextiles on the European Market, the product must meet specific needs, which are not relevant on the markets currently served by the industrial partner. First, the product must be defined according to European standards and considering European concerns, in particular with respect to the determination of the characteristic opening size. Second, the product should offer an enhanced resistance to iron-ochre formation.