Patent ID: 6922608

Claim:
An apparatus for producing an extruded film tube and supplying said tube to a collapsing and roller assembly, comprising: (a) a die for extruding a molten material in the form of a tube; (b) a blower system for supplying and exhausting cooling air to and from an interior portion of said tube, and for regulating at least a portion of said blower system to control extrusion and cooling of said tube, and which determines in part a circumference of said tube; (c) at least one sizing sensor located proximate said tube for sensing said tube's position, comparing such position to an extrusion set point, and generating an extrusion feedback error signal which is corrective of any difference between said position and said set point; (d) at least one lay flat sensor located proximate said tube in a position above said at least one sizing sensor for sensing said tube's position prior to collapsing and flattening of said tube by said collapsing and roller assembly, comparing said position to a lay-flat set point, and generating a lay-flat feedback error signal which is corrective of any difference between said position and said lay-flat set point; (e) a programmable controller for executing program instructions including a feedback control system which receives said extrusion feedback error signal and said lay-flat feedback error signal as feedback injection signals and which provides a control signal to said blower system.