Film extrusion die

Claim 1

In a T-shaped extrusion die for extruding films of thermally flowable synthetic resin at a high pressure, comprising (1) a die body having a manifold for containing a supply of the synthetic resin in molten state and a slot-like passage for passing the molten synthetic resin towards a slot-like discharge orifice, (2) adjustable lips for forming the slot-like discharge orifice of any desired size between their lower ends, (3) inner deckles for varying the edge thickness of the resulting extruded film, movable perpendicularly to the resin flow and within the slot-like passage at the end portion of the die body, respectively, and (4) inner deckle rods for regulating the width of the resulting extruded film, movable below the inner deckles in conjunction therewith, parallel to the moving directions of the inner deckles and within the slot-like passage at the end portions of the die body, respectively, said extrustion die characterized in that one of the inner deckles being securely connected to, and supported by, a support rod extending through the manifold beyond one end of the die body and provided at the outer end with a support rod-power driving device for moving the support rod in sliding contact with the surface of the manifold, the other being securely connected to, and supported by, a similar support rod extending through the manifold beyond the other end of the die body and provided at the outer end with a support rod-operating device for moving the other support rod in sliding contact with the surface of the manifold, the support rod-power driving device being manually operable or remote-operable at the side of the support rod-operating device, and the inner deckle and the mating inner deckle rod being kept a predetermined distance away from each other thereby to permit the latter to move easily without being closely contacted with the former during the high-pressure extruding operation.