| 摘要 |
<p>A die head (10) is disclosed for use on an extruder die comprising a plate-like structure (11) having an elongated slot (12) through which extrudate (30) is extruded. The slot has a central area which is narrower than the height at each end of the elongated slot. The elongated slot (12) also is arcuate in shape, and the central area to each portion is a mirror image of one another. The die head (10) produces an extrudate (30) which is uniform in thickness throughout a cross-section taken normal to the direction of extrusion, but the extrudate is bowed or arcuate in shape. The combination of a metallic shell (40) and a flexible arcuate magnetic material (30) is also disclosed in which the extruded flexible magnetic strip material is curled within the cylindrical shell (40) such that both the peripheral exterior surface (38) and the peripheral interior surface (39) of the flexible magnetic material is flat in axial cross-section.</p> |
