Method of preforming friction material

摘要

A friction material matrix 2 consisting of a mixture of a fibrous base material, a binder, and various fillers is introduced into a molding die 3. Rod members 5 are inserted into the molding die 3 from above. The rod members 5 are vertically actuated while a stroke of the actuation of the rod members 5 is gradually reduced. The friction material matrix 2 is compressed until its volume becomes 50 to 60 vol. % of the initially introduced friction material matrix 2. Then, a bottom plate 4 is raised to compress the friction base matrix 2, so that the friction base matrix 2 is preformed.