A method and system of forming a fire door core. Hydraulic binder and resin are supplied from raw material bins and mixed to provide a submixture. Exfoliated vermiculite is then mixed with the submixture to provide a mixture that is deposited into a plurality of compression molds. Each of the filled...http://www.google.es/patents/US6773639?utm_source=gb-gplus-sharePatente US6773639 - Method of and system for forming a fire door core
