| abstract |
A method of forming a composite material by providing a quantity of first particles of a binder material and a quantity of second particles of a primary material having softening temperature substantially in excess of the softening temperature of the binder material. The first and second quantities of particles are combined into a substantially uniform mixture. The uniform mixture is heated in the absence of pressure or shear sufficient to convert the binder particles, to a temperature substantially above the softening point of the binder material but less than the softening temperature of the primary material. Thereafter, pressure and shear are applied to the heated mixture sufficient substantially immediately to convert at least a portion of the binder material particles into a substantially continuous webbing structure or force the formation of point-bonds. Substantially immediately after formation of the binder particles into this unique structure, the mixture is rapidly cooled to below the softening point of the binder material to retain the converted binder material in its continuous form or forced point-bonded condition. This produces the composite material composed of primary particles, a binder resin phase forming a continuous web matrix or point bonds, and a volume of empty pores. Also disclosed are products formed by the method. |