Patent ID: 8273276

Claim:
A method of extruding a flow of material through a laterally expanding flow channel defined by a pair of opposite side walls and having a flow inlet located at one end thereof and a flow outlet located at an opposite end thereof, comprising: extruding a flow of material through the laterally expanding flow channel between the flow inlet and the flow outlet to laterally expand the flow of material; narrowing a height of the flow channel proximate a general central portion thereof with a flow restrictor disposed within the flow channel and spaced from the opposite pair of side walls, the flow restrictor having a height that increases along a substantial entire length of the flow restrictor from the flow inlet located at the one end of the flow channel to the flow outlet located at the opposite end of the flow channel to thereby narrow a thickness of the laterally expanded flow of material proximate a general central portion thereof; and extruding the laterally expanded flow of material from the flow outlet.