METHOD FOR THE PREPARATION OF POLYURETHANE (PUR) AND POLYURETHANE/POLYISOCYANURATE (PUR/PIR) - RIGID FOAMS

摘要

The invention relates to a process for the production of polyurethane (PUR) and polyurethane / polyisocyanurate (PUR / PIR) rigid foams, comprising the steps i) preparing 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 polyetherester polyols, B) a polyisocyanate component and C) a propellant D) optionally a catalyst component E) optionally auxiliaries and additives, ii) applying the reaction mixture to a system comprising at least one casting device, wherein the casting device (100) comprises: - An inlet port (12) for feeding the reaction mixture (10), at least one outlet gap (13) extending in a transverse direction (Q) to exit the reaction mixture (10), - Two oppositely arranged split plates (14), wherein in a height direction (H) above the outlet gap (13) extends a gap space (15) between the gap plates (14), characterized in that - An inlet channel (16) connected to the inlet port (16) between the gap plates (14) is formed, which closes the gap space (15) above the outlet gap (13) in the height direction (H), wherein - The inlet channel (16) has a channel cross-section (17) whose main dimension is greater than the width (B) of the gap space (15), so - The reaction mixture over the length of the inlet channel (16) distributed in the gap space (15) can be introduced.