Die for extruding a honeycomb structural body

Claim 1

In a die for extruding a honeycomb structural body comprising discharge slits having a cross-sectional shape corresponding to that of the honeycomb structural body and having a given depth towards the rear surface of the die from the front surface, and an opening portion having a plurality of openings which are connected to the discharge slits at intersecting portions or side portions thereof, an improvement further comprises at least one set of a throttle portion having a plurality of openings and a reservoir portion secured to the rear surface of the opening portion in such an arrangement that the reservoir portion is provided between the throttle portion and the opening portion, the openings in the throttle portion in one set of the throttle portion and the reservoir portion, which set is arranged at the rear side of the opening portion, being larger in diameter and smaller in number than those in the opening portion, said reservoir portion being constituted with a plurality of guide channels connecting adjacent openings of the throttle portion with one another and the openings in the opening portion; the discharge slits, the opening portion and at least one set of the throttle portion and the reservoir portion being constructed in monolith, whereby a raw stock flow supplied to the openings in the throttle portion is spread into the guide channels in the reservoir portion, the spread raw stock is fed into the openings in the opening portion and finally, the raw stock flow passed through the openings in the opening portion is extruded through the discharge slits.