| 摘要 |
A multilayer pipe (2) is formed. The multilayer pipe (2) comprises at least two inner layers (2a, 2b, 2c) between the layers (2a, 2b, 2c) there is adhesive material (7). The adhesive material (7) or the materials in the layers (2a, 2b, 2c) are modified such that at least one physical property of the adhesive material (7) between the layers (2a, 2b, 2c) differs from the physical properties of the material in at least one layer (2a, 2b, 2c) such that the thickness of the layer (2a, 2b, 2c) is detected with x-ray imaging. |
