In the preparation of polyurethane foam by the provision of foamable urethane composition to a trough and subsequent overflow of the trough to a conveyor belt for final foaming and curing of the urethane composition, improved product is obtained by maintaining temperature uniformity laterally across...http://www.google.de/patents/US4298557?utm_source=gb-gplus-sharePatent US4298557 - Method and apparatus for the preparation of foamed structures
