Recticel

Prefoam Ag

Rudi Mortelmans

Lucien Jourquin

Brian James Blackwell

Eddie R Du Prez

Peter De Wilde

Eddie DuPrez

Mario Genetello

Patrick Demeyer

Hendrik Pauw

Philippe Vander Schelden

Koen Raman

Robertus H Evers

Dieter Van Damme

Johannes A Derksen

Karel Poppe

The compressible sealing element () comprises at least one piece made of a resilient foam (). This foam has an open-cell content of at least 50% and has such a hardness that it requires a force of less than 2000 N to compress the sealing element () per meter length thereof to such an extent that the volume of a rectangular cuboid circumscribing the sealing element is reduced by 40%. The sealing element comprises a water-impermeable cover layer () which extends at least over its top surface. The sealing element is intended for filling at least partially the gaps between the stock rails () and the switch rails () in a railway switch to prevent the switch from being blocked in particular by snow. Advantages of the new sealing element is that it can easier be inserted in these gaps and that it has a smaller effect on the force required to close the switch so that it can also be applied closer to the free extremity of the switch rail ().

Compressible sealing element and use thereof for filling the gap between a stock rail and a switch rail in a railway switch

The flexible, resilient polyurethane foam is prepared by reacting at least one polyisocyanate with one or more liquid compounds which have at least two isocyanate reactive groups and at least one of which contain one or more solid polymers stably dispersed therein in an amount of 2.5 to 35 parts per 100 parts of said liquid isocyanate reactive groups containing compounds. The wet compression set of the flexible polyurethane foam could be considerably reduced by including in said liquid isocyanate reactive groups containing compounds, per 100 parts thereof, (I) 50 to 80 parts of one or more polyoxyalkylene polyols having an oxyethylene unit content of at least 40 wt. %, a hydroxyl number of between 20 and 100, and a nominal functionality of 2 to 4; and (II) 20 to 50 parts of one or more further polyoxyalkylene polyols containing no oxyethylene units or having an oxyethylene unit content lower than 40 wt. %, and having a hydroxyl number of between 20 and 100 and a nominal functionality of 2 to 4.

Process for the preparation of flexible, resilient polyurethane foam and the resulting foam

A method and device for continuously producing slabstock polyurethane foam wherein a polymerizable reaction mixture containing a blowing agent is applied onto a moving conveyor and allowed a free rise expansion and polymerization within a substantially closed space. The pressure in this space is maintained within a predetermined pressure range by continuously supplying gas to the space, in addition to the blowing gas produced by the reaction and by simultaneously exhausting gas from said space. In this way, pressure fluctuations are reduced in the space and further parameters such as the temperature can be controlled so as to enable production of a foam with constant properties.

Method and device for the continuous manufacture of slabstock

Device for the continuous manufacture of slabstock polyurethane foam

A method for the manufacture of flexible polyurethane foam of a density between 35 and 70 kg/m.sup.3 and having improved comfort properties, wherein a reaction mixture is composed containing at least a polyether polyol of equivalent weight between 1400 and 2800 and having a primary hydroxyl group content of more than 50%, an organic polyisocyanate, a catalyst and 0.5 to 1% by weight water with respect to the total foam weight and wherein, in order to allow the reaction mixture to expand up to said density by means of this limited amount of water and by means of up to 1.5 mole of a physical blowing agent per mole polyol, the reaction mixture is frothed mechanically and/or the reaction mixture is allowed to expand under a reduced pressure.

Method for the manufacture of flexible polyurethane foam

A method for preparing a flexible polyurethane foam, wherein a polyether-polyol having an average molecular weight from 1000 to 8000 and an average functionality not larger than 4, is brought into reaction with an organic polyisocyanate in the presence of a foam stabilizer, a catalyst and blowing agent comprising methylformate, wherein a cross-linker/extender and/or amine catalyst with delayed action is added to said reaction mixture.

Method for preparing a flexible polyurethane foam

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Ghent, Belgium

Rudi Mortelmans