Non-woven product that contains organic and/or mineral particles and its process for production

20) Process for the production of a flexible, non-woven product that has a volume density that is less than 1 and that is formed by at least two layers of fibers or filaments that are superposed in the Z direction that is perpendicular to the XY plane of said product, having undergone at least one mechanical or hydraulic needling operation, whereby said non-woven product also integrates particulate feedstocks in the form of mineral and/or organic particles distributed in a monomodal or multimodal manner in this product and at least partially coated or encapsulated by a binding material that can at least point-connect the filaments or fibers to one another,

• process that is characterized in that it consists in implementing—prior to, simultaneously with or following—the integration of the binding material in and/or between the layers of fibers or filaments, whereby one stage for incorporating mineral and/or organic particulate feedstocks comprises at least one population or fraction of the organic and/or mineral particles, called “large particles,” and has an individual volume such that 3×(√{square root over (SMf)})3≦v, preferably 5×(√{square root over (SMf)})3≦v, where SMf corresponds to the mean cross-section of the fibers or filaments that form the layers of the non-woven product, and v represents the mean individual volume of the organic or mineral particles.