In agricultural, environmental and construction end uses, new developments will provide technical textiles with an even greater role, writes European correspondent.

Spunbond polypropylene nonwovens are extensively employed for crop protection and to enhance plant cultivation

Polypropylene (PP) continues to be the fibre of choice for technical textiles for agricultural, environmental and construction end uses.

In nonwoven form, PP materials are now extensively employed as building substrates for roofing, as geotextiles and as agricultural crop covers.

PP is also the fibre employed in woven products such as Flexible Intermediate Bulk Containers (FIBCs), other geotextiles and sacks, and in tufted form as synthetic grass for both sports surfaces and landscaping.

At the Executive Seminar of the European Association of Textile Polyolefins (EATP), held on May 27 in Brussels, Belgium, Selim Akdogan, the association’s president, observed that Europe – including Turkey – remains the world’s largest producer of polypropylene fibres.

Consumption may take time to recover

The Greater European consumption of polypropylene textile products fell from 2.3 million tons in 2008 to 2.1 million tons in 2009, according to early market projections provided by the EATP’s secretary general Albert Prisse. This was a fall of 4.8% on the back of a 6.2% drop in 2008 compared to 2007.

Of the 2009 figure, 655,000 tonnes went into spunbond and meltblown nonwovens, 490,000 tonnes was turned into slit film and tape, 430,000 tonnes was used as staple fibre, 395,000 tonnes as multifilament fibres, 103,000 tonnes as strapping and 62,000 tonnes as monofilament.

Spunbond and meltblown nonwovens usage has continued to grow through the recession, as has monofilament, as a result of its substitution of slit films and tapes in synthetic grass production.

Overall, however, Mr Prisse said a return to the consumption achieved in 2007 is not anticipated before 2013.

Speaking about nonwovens in general, Jean-Michel Anspach of EDANA (the European Disposables and Nonwovens Association) observed that European nonwovens had achieved average compound growth of 7.5% between 1998 and 2008, but that the smallest growth for many years was registered in 2008, when production was 1,720 million tonnes, based on an average weight of 34.4 gsm – equating to 50 million square metres.

“Unfortunately,” said Mr Anspach “the figures for 2009, once we have finally compiled them, will certainly be less than this.”

Of end-use markets, a lot of growth has been achieved by wipes over the past ten years, and filtration has become an increasingly important market.

In the recent recession, however, technical markets for nonwovens such as roofing substrates, geotextiles, and particularly automotive, have been severely affected.

“A recovery in the automotive sector is not anticipated until at least 2014,” said Mr Anspach.

Of the total European nonwovens production in 2008, 758.7 million tonnes, was spunmelt, polymer-to-web materials.

“Polymer-to-web processes have grown at a higher rate of 8-9% in the last ten years, with polypropylene as the fibre accounting for 80% of it, and not just in Europe, but the world,” said Mr Ansbach.

Increasingly, there is a move towards enhancing the functionality and adding intelligence to fabrics for agricultural, environmental and construction end uses, such as the seismic wallpaper recently developed by Italy’s D’Apollonia and partners in the EU-funded Polytect project.

This will be used for the reinforcement, strengthening, monitoring and management of civil infrastructure vulnerable to earthquakes.

As part of the 10.2-million-euro Polytect project, sensor-embedded grids and filters are being developed for use in structural health monitoring (SHM) in geotechnical and masonry applications.

Increasing role of textiles in construction field

The seismic wallpaper developed to monitor structural changes in buildings

SHM, originally developed by the aerospace industry and now extending to civil and mechanical engineering infrastructure, is a process of implementing a damage detection strategy.

It involves the observation of a system such as a building, road or embankment, over time, using periodically sampled dynamic response measurements from an array of sensors, the extraction of damage-sensitive features from these measurements, and their statistical analysis.

Textiles and nonwovens are already routinely employed in the construction of civil infrastructure. In ground construction, they stabilise or strengthen soil, and can act as filter membranes or water blockers. In building construction, they provide efficient reinforcement, especially in older masonry structures that are vulnerable to natural hazards.

Now it is widely believed they could play a much greater role in respect of the structural strengthening and increasing of ductility in structures, in addition to monitoring many parameters, including deformation, stress, structural integrity, water level variations and pore pressure, in addition to the detection of fluids and chemicals.

Such information could then be employed to make a health assessment of the structure concerned.

The Polytect project team redoubled their development efforts following the L’Aquila earthquake in Italy in Spring 2009, when 15,000 houses destroyed.

Large textile machines were adapted to allow the warp knitting of fibre-optic cables into multiaxial fabrics. The textile fibre material type, orientation and density were optimised for the large forces and complex material behaviour associated with civil infrastructure, masonry and earthquakes. Multiaxial textile structures are superior in this respect.

The textile was then coated for durability and to enhance the textile-mortar bond interface. The specific nanoparticle-enhanced polymer coatings for the innovation were produced by the team members. The textiles were subsequently applied to a structure using a mortar compound, which was also enhanced by nanoparticle polymer additives.

Easy to apply

The composite seismic wallpaper is intended as a full coverage or wide-area reinforcing solution for unreinforced masonry buildings and structures. The solution is simple, cost-effective and easy to apply.

When applied as a full coverage solution and tested in large-scale laboratories that conduct national standardisation testing for Germany, it provided over 200% increases in structural strength (maximum load) and over 200% increases in structural ductility (maximum deformation).

Walls vulnerable to brittle behaviour and collapse were being held together even after they cracked. The composite features embedded sensors so that measurements can be taken before, during, and after seismic events. These measurements can be static or dynamic (high frequency). Engineers employ such data to control new construction, to assess and quantify the benefit of retrofit actions and to help manage the structure over time.

Polytect partners include the Karlsruher Institut fur Technologie in Germany, Selcom Multiaxial Technology in Italy, Sachsisches Textilforschungsinstitut in Germany, Karl Mayer Malimo Textilmaschinenfabrik of Germany, Sweden’s APC Composite, Extreme Materials, TexClubTec and Consorzio Cetma all in Italy as well as several other laboratories, companies and end-users from Europe, Israel and India.

New geotextile monitoring solution

In a parallel development, Roctest, the world’s largest manufacturer of fiber optic sensors for civil engineering applications, is to collaborate with Netherlands-headquartered technical textiles leader TenCate on the development of the GeoDetect geotextile monitoring solution.

GeoDetect can provide unprecedented details about the properties of embankments, slopes, walls, levees, roads, railways and other earth structures and users will benefit from the real-time monitoring of every square meter of land for ground movement, soil erosion, settlement and other changes.

TenCate's Geodetect system is the first sensor-enabled geotextile which provides soil reinforcement and structural health monitoring with an early warning system

Through its subsidiary Smartec SA, Roctest is now working with TenCate Geosynthetics on the technical and commercial development of geotextiles equipped with optical fiber sensors and related monitoring services.

TenCate began the development of geosynthetics with monitoring capabilities several years ago. Since then several pilot projects have been initiated, including those with the French Railways (SNCF) and with water management projects funded by the Dutch government. GeoDetect is the first sensor-enabled geotextile to provide soil reinforcement, structural health monitoring and an early warning system in one package, and in combination with Smartec’s wide range of sensors, including fiber optic, vibrating wire and conventional types, will provide an unparalleled package of data analysis tools for structural engineering and geotechnical applications.

These technologies can be incorporated into a single user interface developed by Smartec called SHMLive. The SHMLive platform is designed for continuous monitoring through real-time data transfer via a secure online database and can be used to store and share all documents related to a monitoring project, including reports, plans and other useful information. SHMLive is offered for a fixed monthly fee that includes all the sensors, data acquisition units, aggregation device, upload transmission link, secure database storage, real-time analysis, web-based data access and reporting, with performance levels guaranteed for the contract duration.

“For Roctest, the TenCate Geosynthetics relationship increases our ability to provide customers with the most integrated and innovative products for structural health monitoring, and reinforces our strategy of offering the most complete toolbox of solutions to our customers,” said Francois Cordeau, president and chief executive officer of Roctest.

“The future for TenCate Geosynthetics is less about products and more about providing solutions for geotechnical challenges through a systems approach,” added Dave Clarke, group director for TenCate Geosynthetics. “Coupling our application expertise with Roctest’s sensor technology provides a differentiated approach to detecting potential failures and/or problems for civil engineers.”

FIFA 2010 matches on synthetic turf

FIFA World Cup matches were played on synthetic grass for the first time in 2010 at South Africa's Polokwane Peter Mokaba stadium

Meanwhile, for the first time in history, matches in a FIFA World Cup were played on pitches made of synthetic turf during the 2010 tournament.

The Desso GrassMaster system from Desso Sports Systems was installed at two South African stadiums in Nelspruit (Mbombela) and Polokwane (Peter Mokaba).

With a capacity of around 45,000 spectators each, both new stadiums hosted four group matches.

The Desso GrassMaster system is made up of a 100% natural grass surface, into which 20 million artificial turf fibres are injected to a depth of 20 cm.

The roots of the natural grass intertwine with the artificial fibres, which anchors the field into a stable and a level grass surface.

Thanks to the reinforcement of artificial grass fibres, Desso GrassMaster offers reliable pitches in all weather conditions and the pitches will continue to serve for football and for rugby games.

“Supplying the stadium pitches for the 2010 FIFA World Cup is obviously a prestigious project for our company,” said Desso CEO Stef Kranendijk. “By doing so, we hope to contribute to the legacy of this tournament and to inspire future top events.”

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