A method to produce products made of composite material having solid particles embedded in a polymeric matrix provides for conveying a viscous liquid suitable to define the polymeric matrix along a first path; conveying agglomerates of elementary solid particles along a second path; combining the agglomerates with the viscous liquid; infiltrating the viscous liquid into the elementary solid particles along a third path by an infiltrating device; and dispersing the elementary solid particles into the viscous liquid along the third path by a dispersing device arranged downstream of the infiltrating device.