Patent ID: 6273701
Filing Date: 2001-08-14
Classification: B29C

Abstract:
A lip die structure including a pair of elongated, laterally spaced lips defining an extrusion slot therebetween having an exit opening from which to extrude molten resin into a web, said die structure including a plurality of thrust elements spaced longitudinally along one of said lips operative to flex said one lip toward and away from the other lip at spaced locations, a measuring component continuously monitoring the thickness of said web and being operative to selectively actuate said thrust elements to flex said one lip toward and away from said other lip selectively at said spaced locations responsive to increases and decreases, respectively, of monitored thickness of said web at points spaced thereacross in alignment with said spaced locations, and a plurality of heating elements longitudinally spaced along said one lip adjacent said exit opening for selectively heating said one lip at selected points spaced therealong, said plurality of heating elements including first and second heating elements, said first heating elements being at selected points in alignment with the spaced locations for flexing said one lip by said thrust elements and said second heating elements being at points spaced between said first heating elements, said measuring component also being operative to selectively actuate and deactuate any of said heating elements responsive to decreases and increases, respectively, of monitored thickness of said web at points spaced thereacross in alignment with said selected points.