Abstract: The invention relates to a method for the production of foamed areal polyurethane(PUR)/polyisocyanurate(PIR) moldings, where a polyurethane/polyisocyanurate reaction mixture is injected into a mold that is under elevated pressure and then a depressurization takes place, and the foaming process is thus induced, and after the reaction the molding is demolded, and to a mold for carrying out the method.

Abstract: The invention relates to a method for the production of foamed areal polyurethane(PUR)/polyisocyanurate(PIR) moldings, where a polyurethane/polyisocyanurate reaction mixture is injected into a mold that is under elevated pressure and then a depressurization takes place, and the foaming process is thus induced, and after the reaction the molding is demolded, and to a mold for carrying out the method.

Abstract: Provided herein is a system for producing a foamed polymer. The system comprises a first mixer for mixing at least two mutually reactive reaction components to obtain a reaction mixture that reacts to afford a polymer. At least one of the reaction components further comprises a supercritical fluid. The system further comprises a foaming mold for receiving the reaction mixture which is connected to the first mixer and has a first volume available for receiving the reaction mixture. The first volume is variable. Also provided herein is a process for producing a foamed polymer.

Abstract: The invention relates to a method for producing a polyurethane foam, wherein a mixture having the following is discharged from a mixing head through a discharge line: A) a component reactive toward isocyanates; B) a surfactant component; C) a blowing agent component selected from the group comprising linear, branched, or cyclic C1 to C6 hydrocarbons, linear, branched, or cyclic C1 to C6 fluorocarbons, N2, O2, argon, and/or CO2, wherein the blowing agent C) is present in the supercritical or near-critical state; and D) a polyisocyanate component. The component A) has a hydroxyl value=100 mg KOH/g and =1000 mg KOH/g. The blowing agent component C) is present at least partially in the form of an emulsion, and means provided with an opening or several openings are arranged in the discharge line in order to increase the flow resistance during the discharge of the mixture comprising A), B), C), and D), wherein the cross-sectional area of the opening or the sum of the cross-sectional areas of all openings is =0.

Abstract: The present invention relates to a process for producing a rigid polyurethane-polyisocyanurate foam C, comprising the step of reacting (i) an isocyanate-terminated prepolymer B with (ii) an activator component A comprising at least one trimerization catalyst A1 and at least one blowing agent A3 in a reaction mixture to form a foam, characterized in that—there is used an isocyanate-terminated prepolymer B obtained from a reaction of an isocyanate B1 having a mean isocyanate functionality of from ?2.3 to ?2.9 with a polyol component B2, and—the activator component A comprises water as the blowing agent A3 in an amount of from ?5 wt. % to ?50 wt. %,—the isocyanate index in the reaction mixture is in a range of from ?400 to ?500, and—the isocyanate content of the prepolymer B is in a range of from ?21 wt. % to ?30 wt. %, based on the total mass of the prepolymer B, and—wherein in the reaction of the prepolymer B and the activator component A a conversion contribution to polyisocyanurate of ?75% is achieved.

Abstract: The present invention relates to a process for producing a rigid polyurethane-polyisocyanurate foam C, comprising the step of reacting (i) an isocyanate-terminated prepolymer B with (ii) an activator component A comprising at least one trimerisation catalyst A1 and at least one blowing agent A3 in a reaction mixture to form a foam, characterised in that—there is used an isocyanate-terminated prepolymer B obtained from a reaction of an isocyanate B1 having a mean isocyanate functionality of from ?2.3 to ?2.9 with a polyol component B2, and—the activator component A comprises water as the blowing agent A3 in an amount of from ?5 wt. % to ?50 wt. %,—the isocyanate index in the reaction mixture is in a range of from ?400 to ?500, and—the isocyanate content of the prepolymer B is in a range of from ?21 wt. % to ?30 wt. %, based on the total mass of the prepolymer B, and—wherein in the reaction of the prepolymer B and the activator component A a conversion contribution to polyisocyanurate of ?75% is achieved.

Abstract: The invention relates to a method for producing a polyurethane foam, wherein a mixture having the following is discharged from a mixing head through a discharge line: A) a component reactive toward isocyanates; B) a surfactant component; C) a blowing agent component selected from the group comprising linear, branched, or cyclic C1 to C6 hydrocarbons, linear, branched, or cyclic C1 to C6 fluorocarbons, N2, O2, argon, and/or CO2, wherein the blowing agent C) is present in the supercritical or near-critical state; and D) a polyisocyanate component. The component A) has a hydroxyl value=100 mg KOH/g and =1000 mg KOH/g. The blowing agent component C) is present at least partially in the form of an emulsion, and means provided with an opening or several openings are arranged in the discharge line in order to increase the flow resistance during the discharge of the mixture comprising A), B), C), and D), wherein the cross-sectional area of the opening or the sum of the cross-sectional areas of all openings is =0.