| 摘要 |
The present invention relates to a perforated thermoplastic structure comprising at least a first layer ( 8 ) and a plurality of perforations, which extend through the first layer ( 8 ). The perforations have a three-dimensional, preferably approximately conical or cylindrical shape ( 18 ). A second layer forms an inner surface ( 20 ) of the shape ( 18 ), whereas the first layer forms an outer surface ( 21 ) of the shape ( 18 ). The first layer contains a thermoplastic material, whose melting point is lower than a melting point of the thermoplastic material of the second layer. |
