Abstract: A method includes steps of extruding rubber or synthetic resin mixed with short fibers from a sectionally annular mold opening, and molding a cylindrical body of rubber or synthetic resin with short fibers oriented in a predetermined direction. The mold opening has an expansion portion 9 whose diameter expands in an extrusion direction, and a flow passage width Wi of an inlet portion 6i of the mold opening, a flow passage width Wo of an outlet portion 6o, and radiuses Ri and Ro of the inlet portion 6i and the outlet portion 6o respectively that are coaxial with the mold opening satisfy a relation of Wo/Wi<Ro/Ri. The value of Ro/Ri is adjusted within a scope of 2?Ro/Ri?8 by changing the radius Ri of the inlet portion according to mechanical properties in the circumferential direction of the cylindrical body to be molded, so that orientation of the short fibers is adjusted.

Abstract: A method comprises steps of extruding rubber or synthetic resin mixed with short fiber from a mold opening 6 of sectionally annular and molding a cylindrical body of rubber or synthetic resin with short fiber oriented in predetermined direction. And the mold opening 6 is passed through with an expansion portion 9 whose diameter expands in extrusion direction, and a flow passage width Wi of an inlet portion 6i of the mold opening, a flow passage width Wo of an outlet portion 6o, and radiuses Ri and Ro of the inlet portion 6i and the outlet portion 6o respectively that are coaxial with the mold opening satisfy a relation of Wo/Wi<Ro/Ri. And value of Ro/Ri is adjusted within a scope of 2?Ro/Ri?8 by changing the radius Ri of the inlet portion according to mechanical property in circumferential direction of the cylindrical body to be molded, so that orientation of the short fiber is adjusted.

Abstract: An apparatus is provided for manufacturing a fiber reinforced elastic sheet by extruding and processing an elastomer containing staples by 25 volume % or less. The apparatus includes a flow adjustment portion provided in a flow path direction of the elastomer for insuring a uniform flow of the elastomer in a sheet width direction. A weir portion is provided on the downstream side of the flow adjustment portion. A clearance Wo of an outlet in the vertical direction of the sheet, a clearance Wi formed by the weir portion in the vertical direction of the sheet and a distance l between the weir portion and the outlet have the relationship ofWo/Wi.gtoreq.2l.gtoreq.3Wo0.3 mm.ltoreq.Wi.ltoreq.5 MMin order to uniformly orient the staples along the thickness of the sheet.

Abstract: A method for manufacturing a fiber reinforced elastic sheet by extruding and processing an elastomer containing staples by 25 volume % or less. The elastomer, which uniformly flows in a sheet width direction, passes through a slight clearance of a molding die in the vertical direction of the sheet, and then the elastomer flow is enlarged in the vertical direction of the sheet. A flow adjustment portion is provided in a passage of the elastomer to flow uniformly in the sheet width direction, and a weir portion is provided on the downstream side of the flow adjustment portion. A clearance Wo of an outlet in the vertical direction of the sheet, a clearance Wi formed by the weir portion in the vertical direction of the sheet and a distance l between the weir portion and the outlet have the relationship ofWo/Wi.gtoreq.2l.gtoreq.3Wo0.3 mm.ltoreq.Wi.ltoreq.5 mm.

Abstract: A roller for running a flat belt is formed at its surface by an elastic body. Short fibers are mixed with the elastic body. The short fibers are averagely oriented in a direction radially or peripherally inclined to the roller with a small angle and protrude at their tip portions from the roller surface. Owing to a grip force of the protruding short fibers, the flat belt is running, while decreasing a friction coefficient and obtaining a stability to a variation of temperature and humidity. The short fibers may be oriented in a direction axially, peripherally inclined thereto with a specific angle. When a belt guide member is provided to the roller or flat belt, accurate running of the belt is performed.