| 摘要 |
<p>A film (10, 90, 108, 110) of uniform thickness is formed by two or more materials (A, B, etc.) extruded side-by-side with their common edge joined and co-mingled to form a single piece film. The film (10, 90, 108, 110) is preferably formed in a conventional slot die (20, 42, 60, 70, 80, 100) by use of a barrier (24, 44, 45, 64, 74) or barriers (104, 106) dividing the entry manifold into two or more passages so that the materials co-mingle downstream of the barrier at their common edge (12). A separate passage (82) in a die (80) can substitute for a barrier. In one application, the film can be extruded partially clear and partially opaque to form a bread wrapper providing a contrasting background for printing.</p> |
