Abstract: The compressible sealing element (1) comprises at least one piece made of a resilient foam (17). 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 (1) 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 (18) which extends at least over its top surface. The sealing element is intended for filling at least partially the gaps between the stock rails (13) and the switch rails (12) 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 (12).

Abstract: The compressible sealing element (1) comprises at least one piece made of a resilient foam (17). 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 (1) 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 (18) which extends at least over its top surface. The sealing element is intended for filling at least partially the gaps between the stock rails (13) and the switch rails (12) 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 (12).

Abstract: 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.

Abstract: 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.

Abstract: The invention relates to polyurethane foams comprising polymers of heterocyclic N-vinyl monomers (i) and a disinfectant or bleaching agent (ii).

Abstract: 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.

Abstract: The present invention relates to a device for the continuous manufacture of slabstock polyurethane foam including a conveyor means (1), a mixing head (51) and means (6) for discharging the reaction mixture from the mixing head (51) onto the conveyor means (1). The device further includes a start board (7), a stop board, means for moving the start board (7) along the conveyor means at the beginning of a production run in such a manner that it obstructs the moving reaction mixture to thereby increase the height of the first portion of the produced foam, and means for moving the stop board at the end of a production run in such a manner that it pushes the foaming reaction mixture ahead to thereby increase the height of the end portion. In this way, no operator has to enter the foaming machine and the start and end profiles of the foam blocks are optimised.

Abstract: 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.

Abstract: 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.