Sekisui Chemical Co., Ltd., established in 1947, is awidely diversified Japanese corporation with over200 companies operating in 20 countries. Sekisuiprovides a broad range of products, from high per-formance plastics and environmental solutions tosynthetic lumber for railroads and factory-producedmodule housing.

ESLON Neo Lumber FFU, a synthetic wood develo-ped for use as railway sleepers in 1978 has sincethen been widely applied in Japan’s railroad infra-structure, from the high speed Shinkansen to regio-nal trains and urban metro systems. So far, morethan 870 km of track have been laid with FFU, mainareas of application are turnouts, open steel girderstructures and tunnels. The idea behind this was todevise a synthetic material featuring the same pro-perties as natural wood, plus an extended life-spanand weathering resistivity. Therefore, FFU is a per-fect symbiosis between wood and plastic, combi-ning the advantages of both materials.

Eslon FFU Neo Lumber for railroad application isproduced by compressing single strands of glassfibre with polyurethane foam using a high pressureextraction press. The manufacturing process is in-itiated by mixing the base materials polyole and iso-cyanide with several additives. After compoundingand extrusion, the raw mixture is reinforced withlong glass fibres. Foaming and curing are the final

manufacturing stages before the finished product iscut to a standard length of 12 metres for further pro-cessing. The continuous extrusion method allows theproduction of sleepers in any length, the only re-striction being transportation capacities. Sekisui syn-thetic wood railroad and bridge sleepers can befabricated to millimetre accuracy according to cus-tomer specifications. A priceless advantage for trackprecision accuracy.

Pre-Assembly at Voestalpine BWG

Installation of Turnout at Bayer Leverkusen Plant

Rail Fastening System Analog to Wood

FFU Synthetic Railway Sleepers

Scrap fibres or shavings can easily be recycled. Asopposed to natural wood, FFU does not need to beimpregnated with environmentally harmful chemi-cals, while still resistant against chemical contami-nation and lubricants. Due to its closed cellstructure, FFU does not absorb water, making it ahomogenous, high-grade technical material. Afterinstallation, FFU remains inherently stable, i.e. evenunder extreme strain, the material sits solidly on thesteel beams without any distortions. The bottom side

of the FFU sleeper interlocks with the ballast trackjust like natural wood.Practical experience showsthat effective load deflection and tight bonding bet-ween sleeper bolts and synthetic wood, along withweathering resistivity and a closed cell structure arethe key factors for lower maintenance costs and apositive cost-benefit analysis in the long run. In ad-dition, FFU waste can be re-fabricated into railwaysleepers not subjected to heavy traffic or loads.

FFU can easily be drilled with commercial tools, asprocessing requires the same procedure as naturalwood. Easy to repair, misplaced boreholes can easilybe fixed by inserting an FFU dowel and re-drillingthe hole in the correct position after a short waitingperiod. It is also possible to custom-fabricate indivi-dual FFU sleepers based on client blueprints, offe-ring an unlimited number of design possibilitiesincluding cut-outs, notches, and tapering. Varioussleeper widths and lengths are available accordingto customer requirements.

The year 2004 marked the European premiere forEslon FFU Neo Lumber. Wiener Linien urban metro

systems opted for the application of FFU as sleeperson an open steel girder bridge inVienna. So far, FFUhas been used on several otherWiener Linien bridgeprojects. Since 2005, Austrian Federal Railways ÖBBuses FFU ‘polyurethane wood’ in diverse railroad in-frastructure projects. Recently, the Bayer AG subsi-diary Currenta Leverkusen installed a FFU turnout74 meters long in order to connect the production

site to the Deutsche Bahn railroad net. The turnoutwas manufactured by Voestalpine BWG.

The durability of Eslon FFU Neo Lumber is muchhigher than that of natural wood. The initial invest-ment for installation in the track superstructure isslightly larger when FFU is used, but is in turnquickly offset by lower life cycle costs and technicalsuperiority. Environmentally responsible rail opera-ting companies generally make their purchasing de-cisions in favour of synthetic wood.

Easy Manual Adjustment

Final Installation of Turnout

SEKISUI Chemical GmbHCantadorstr. 3, D-40211 Düsseldorf, Tel.: +49-211-36977-0, Fax: +49-211-36977-31, e-mail: ffu@sekisui.de