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|1. (WO2018141721) PROCESS FOR PRODUCING RIGID POLYURETHANE (PUR) AND POLYURETHANE/POLYISOCYANURATE (PUR/PIR) FOAMS|
|Applicants:||COVESTRO DEUTSCHLAND AG
|Title:||PROCESS FOR PRODUCING RIGID POLYURETHANE (PUR) AND POLYURETHANE/POLYISOCYANURATE (PUR/PIR) FOAMS|
The invention relates to a process for producing rigid polyurethane (PUR) and polyurethane/polyisocyanurate (PUR/PIR) foams, comprising the steps of i) producing a reaction mixture containing the components A) an isocyanate-reactive component containing at least one polyol selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, polyether polycarbonate polyols and polyether ester polyols, B) a polyisocyanate component and C) a blowing agent, D) optionally a catalyst component, and E) optionally auxiliaries and additives,ii) applying the reaction mixture by using a system comprising at least one casting device, said casting device (100) having: - a supply port (12) for feeding the reaction mixture (10), - at least one discharge gap (13) extending in a transverse direction (Q) for the discharge of the reaction mixture (10), - two gap-forming plates (14) arranged opposite one another, a gap space (15) extending between the gap-forming plates (14) above the discharge gap (13) in a height direction (H), characterized in that - between the gap-forming plates (14) and connected to the supply port (12) there is a supply duct (16) which closes the gap space (15) above the discharge gap (13) in a height direction (H), - the main dimension of the duct cross-section (17) of the supply duct (16) is greater than the width (B) of the gap space (15), and therefore - the reaction mixture can be introduced into the gap space (15), distributed over the length of the supply duct (16).