| 摘要 |
<p>A foamable extrudate is extruded through the orifice (25), preferably arcuate, of an extrusion die (24). Immediately adjacent and downstream of the die orifice are opposed sets of curved rollers (47, 48), each having substantially the same center of curvature as the die orifice. The roller set (48) on one side of the extrudate pass line is adjustable as a set with respect to and substantially parallel to the pass line, while the rollers of the set (47) on the opposite side are adjustable individually cach to float with controlled pressure against the extrudate as it expands and moves between the roller sets. Each roller is comprised of a plurality of thin, cylindrical, circular wafers (195) which are drivingly interconnected and journaled on curved cure shafts (50). The wafers of opposed rollers in each set are individually driven for rotation at a controlled speed so that each opposed pair of rolls acts as a traction drive for the extrudate as it exits radially from the die orifice, such rollers controlling the expansion and movement of the extrudate while minimizing cell distortion. A surface finisher (45) is provided downstream of the roll sets which comprises opposed extrudate engaging planar surfaces (120, 121) positioned on the opposite sides of the extrudate, one (121) being adjustably yet fixedly supported while the other (120) is adjustably and floatingly supported pivotally at its center of gravity to exert a controlled flating pressure on the extrudate.</p> |
