Unvulcanized rubber extruder and process for producing unvulcanized rubber

An unvulcanized rubber extruder having a first extruder main body that extrudes a first unvulcanized rubber, a second extruder main body that extrudes a second unvulcanized rubber, an extrusion head that connects a distal end portion of the first extruder main body and a distal end of the second extruder main body, and a flow path forming mold that leads the first unvulcanized rubber and the second unvulcanized rubber out toward a cap at an extrusion head distal end portion, the unvulcanized rubber extruder extrusion-molding an extruded rubber member having a cross-sectional shape in which, when viewed in a cross-section perpendicular to an extruding direction of the extruded rubber member, a portion of the second unvulcanized rubber penetrates into the first unvulcanized rubber, and a portion of the first unvulcanized rubber is disposed at both sides in a direction intersecting a penetrating direction that the second unvulcanized rubber has penetrated,

• wherein the flow path forming mold has a first flow path that passes the first unvulcanized rubber toward the cap;
• a second flow path that is provided parallel to the first flow path and passes the second unvulcanized rubber toward the cap, the second flow path includes a first inclined surface and a second incline surface on an upper side, the second inclined surface is located between the first flow path and the first inclined surface and is lower than the first inclined surface at the second flow path;
• and a third flow path that opens at a side wall of the second flow path and causes the first unvulcanized rubber to flow-out toward a side surface in a horizontal direction of the second unvulcanized rubber flowing along a side of the second inclined surface, and
• the unvulcanized rubber extruder connects the first unvulcanized rubber, that has flowed-out from the third flow path, to a portion of the first vulcanized rubber that flows through the first flow path, and sandwiches-in a portion of the second unvulcanized rubber by a portion of the first unvulcanized rubber that flows through the first flow path and the first unvulcanized rubber that has flowed-out from the third flow path.