| 摘要 |
Composite material (I) (preferably made of extrudable materials) with at least two opaque layers (2, 3) bonded together and at least one marking section (4), in which the marking section (4) is located between layers (2) and (3) and is readable with the aid of X-rays. An Independent claim is also included for a method for the production of (I) by making a first opaque layer (2) (preferably by extrusion), applying the marking sections (4) and then adding other opaque layer(s) (3) (preferably by extrusion). |
