An extrusion molding method utilizes a mandrel with a small outer diameter region having an outer diameter corresponding to a raw pipe inner diameter and a large outer diameter region having a larger outer diameter than the raw pipe inner diameter on its tip and base end sides respectively. The mandrel is pushed into the raw pipe set in a container which has a small inner diameter region having an inner diameter smaller than a raw pipe outer diameter and a large inner diameter region which has a larger inner diameter than the raw pipe outer diameter on its tip and base end sides respectively to expand a diameter of raw pipe end part on a base end side of the raw pipe. Thereafter, the base end side of the raw pipe having the mandrel inserted inside is pushed into the small inner diameter region of the container.

An extrusion molding method utilizes a mandrel with a small outer diameter region having an outer diameter corresponding to a raw pipe inner diameter and a large outer diameter region having a larger outer diameter than the raw pipe inner diameter on its tip and base end sides respectively. The mandrel is pushed into the raw pipe set in a container which has a small inner diameter region having an inner diameter smaller than a raw pipe outer diameter and a large inner diameter region which has a larger inner diameter than the raw pipe outer diameter on its tip and base end sides respectively to expand a diameter of raw pipe end part on a base end side of the raw pipe. Thereafter, the base end side of the raw pipe having the mandrel inserted inside is pushed into the small inner diameter region of the container.

Embodiments described herein relate to apparatus for extruding a material. The apparatus includes an extrusion die arranged to receive material to be extruded from a first direction and from a second direction. The extrusion die includes an orifice from which material is extruded in a third direction. The first, second and third directions are not all in the same plane. None of the first, second and third directions is parallel to any other of those directions.

Embodiments described herein relate to apparatus for extruding a material. The apparatus includes an extrusion die arranged to receive material to be extruded from a first direction and from a second direction. The extrusion die includes an orifice from which material is extruded in a third direction. The first, second and third directions are not all in the same plane. None of the first, second and third directions is parallel to any other of those directions.