Fishtail die for producing thermoplastic films and sheets

Claim 1

In a fishtail die having a solid and integral die body for the production of film and sheets from a thermoplastic material, a combination in the die body of a feed passage, a first distribution channel extending substantially perpendicularly to said feed passage and communicating therewith, a second distribution channel substantially parallel to and in spaced relation with said first distribution channel, said second distribution channel extending over a greater distance than the length of the first distribution channel and defining the maximum width of a produced film or sheet, said first and second distribution channels being symmetricAl with respect to said feed passage, a plurality of spaced bores in an integral portion of the die body interconnecting said first and second distribution channels to define a permanent and rigid connection laterally through the die in at least one point, and means for selectively adjusting the length of the second distribution channel down to an operating length corresponding substantially to that of said first distribution channel.