A method of manufacturing a strip of unvulcanized rubber compound including short
fibers oriented towards specific directions is disclosed, and the method comprises:
extruding a mixture of unvulcanized rubber and short fibers to form a strip of
the mixture and to orient the short fibers towards the extruding direction; and
piercing the strip with needles in a thickness direction of the strip to orient
the short fibers towards the piercing direction.