Patent ID: 8162644

Claim:
A die for an extrusion forming head, which is mounted to a head for extrusion forming of a rubber, wherein an upstream portion of a rubber forming path reaching a front end outlet from a rubber storing portion at inside of a die main body is provided with a fluid sending inlet for sending a fluid to between an outer peripheral face of a being-formed rubber at inside of the rubber forming path and an inner wall face of the rubber forming path; an inner diameter of the rubber forming path or distance between upper and lower wall faces of the rubber forming path is larger at each portion on downstream of the fluid sending inlet than at any portion on upstream of the fluid sending inlet, in respect of an entire length of the rubber forming path; and, the inner diameter of the rubber forming path or distance between upper and lower wall faces of the rubber forming path is gradually reduced as tapered from the fluid sending inlet to the front end outlet of the rubber forming path; so as to reduce a resistance of passing the being-formed rubber on downstream of the fluid sending inlet, by said fluid.