| 摘要 |
A die for the extrusion of a mix for expansion beyond the die is formed by the nip between cam-surfaced rollers (26', 27') at least one of which is grooved. Extrudate is delivered through over-size nozzle (24) to the nip. Upon pressure rise at the die being sensed, the rollers are rotated through 180 to clear any blockage and to re-form the die with another part of their circumference. Notches (63) on side faces (28') of the nozzle conforming to the roller surfaces (29', 30') assist in preventing back-leakage of the extrudate. <IMAGE> |
