Abstract: A method and device for carrying out a reel splice to avoid the fluttering of tails makes it possible to allow the tail to also adhere across its entire length, in particular on a web with high mechanical strength. When using a fluid-repelling substrate, an adhesive-free liquid is applied to a new roll and/or to at least a portion of the side of the tail facing the web. The method and device can be used in reel splicers which process fluid-repellent substrates, such as for example plastic films, metal films or laminated laminates, so that a sticking out or fluttering of the tail is avoided.

Abstract: A method and device for carrying out a reel splice to avoid the fluttering of tails makes it possible to allow the tail to also adhere across its entire length, in particular on a web with high mechanical strength. When using a fluid-repelling substrate, an adhesive-free liquid is applied to a new roll and/or to at least a portion of the side of the tail facing the web. The method and device can be used in reel splicers which process fluid-repellent substrates, such as for example plastic films, metal films or laminated laminates, so that a sticking out or fluttering of the tail is avoided.

Abstract: The present invention relates to a process for producing a polyurethane foam, where the blowing agent used is present in the supercritical or near-critical state. A reaction mixture is introduced into a closed mould, where the closed mould has been set up in such a way that its interior volume and/or the pressure prevailing in its interior can be altered after the introduction of the mixture by external influence. Through the selection of the surfactant it is possible to obtain microemulsions of the blowing agent in the polyol phase. The invention further relates to a nanocellular polyurethane foam obtainable by the process of the invention.

Abstract: A process for producing a polyurethane foam with bimodal cell size distribution, comprising the following steps: providing a mixture in a mixing head, where the mixture comprises: A) a component reactive towards isocyanates; B) a surfactant component; C) a blowing agent component selected from the group consisting of linear, branched or cyclic C1- to C6-alkanes, linear, branched or cyclic C1- to C6-fluoroalkanes, N2, O2, argon and/or CO2, where blowing agent component C) is present in the supercritical or near-critical state; D) a polyisocyanate component; discharging the mixture comprising components A), B), C), and D) from the mixing head where, during the discharge of the mixture, the pressure prevailing in the mixture is lowered to atmospheric pressure.

Abstract: Process for producing a polyurethane foam and polyurethane foam obtainable therefrom A process for producing a polyurethane foam with bimodal cell size distribution, comprising the following steps: providing a mixture in a mixing head, where the mixture comprises: A) a component reactive towards isocyanates; B) a surfactant component; C) a blowing agent component selected from the group consisting of linear, branched or cyclic C1- to C6-alkanes, linear, branched or cyclic C1- to C6-fluoroalkanes, N2, O2, argon and/or CO2, where blowing agent component C) is present in the supercritical or near-critical state; D) a polyisocyanate component; discharging the mixture comprising components A), B), C), and D) from the mixing head where, during the discharge of the mixture, the pressure prevailing in the mixture is lowered to atmospheric pressure.

Abstract: The present invention relates to a reaction mixture in emulsion form, suitable for conversion into polyurethanes, comprising a first phase and a second phase in the emulsion and further comprising the following components: A) polyols; B) blowing agent; C) surfactants; and D) isocyanates, wherein the isocyanate-reactive compounds A) are present in the first phase of the emulsion and the blowing agent B) is present in the second phase. The blowing agent B) is present in the near-critical or supercritical state and the isocyanate D) is present in the second phase in a proportion of ?10% by weight of the total amount of isocyanate D) in the composition. The invention further relates to a method of producing polyurethane foams by providing such a reaction mixture, wherein a polymerization takes place at the freshly formed interface between the polyol phase and the blowing agent phase, to the use of such a reaction mixture for producing polyurethane foams and also to the polyurethane foams obtained.

Abstract: The present invention relates to a process for producing a polyurethane foam, where the blowing agent used is present in the supercritical or near-critical state. A reaction mixture is introduced into a closed mould, where the closed mould has been set up in such a way that its interior volume and/or the pressure prevailing in its interior can be altered after the introduction of the mixture by external influence. Through the selection of the surfactant it is possible to obtain microemulsions of the blowing agent in the polyol phase. The invention further relates to a nanocellular polyurethane foam obtainable by the process of the invention.

Abstract: A process for producing a polyurethane foam with bimodal cell size distribution, comprising the following steps: providing a mixture in a mixing head, where the mixture comprises: A) a component reactive towards isocyanates; B) a surfactant component; C) a blowing agent component selected from the group consisting of linear, branched or cyclic C1- to C6-alkanes, linear, branched or cyclic C1- to C6-fluoroalkanes, N2, O2, argon and/or CO2, where blowing agent component C) is present in the supercritical or near-critical state; D) a polyisocyanate component; discharging the mixture comprising components A), B), C), and D) from the mixing head where, during the discharge of the mixture, the pressure prevailing in the mixture is lowered to atmospheric pressure.

Abstract: A method for producing rigid sugar micro-/nanofoams includes providing a solution with at least one sugar, a super- or near-critical fluid and a surfactant component as a (micro)emulsion. The (micro)emulsion is expanded so as to convert the super- or near-critical fluid from a state of liquid-like density to a state of gaseous density so as to thereby obtain a micro-/nanofoam. The micro-/nanofoam is then rigidified so as to obtain a rigid sugar micro-/nanofoam.