| 摘要 |
A twin-wall composite sheet (8) comprising (a) at least one inner thermoplastic polymer film (2), and (b) at least two external thermoplastic polymer films (4 and 5) is described. The inner film (2) is interposed between and connected to at least two of the outer films (4 and 5). The inner film has a three-dimensional structure comprising a plurality of at least one of elevations and depressions. The inner film has two main directions of extension, and the three-dimensional structure of the inner film has a substantially periodically recurring pattern in the two main directions of extension thereof. The inner film is fixedly connected to at least two of the outer films in a region of maximum height of elevations of the inner film and/or a region of the maximum depth of depressions of the inner film. The twin-walled composite sheet preferably has substantially the same flexural modulus in the two main directions of extension of the inner film. Optionally, the twin-wall composite sheet can be provided with an external profile selected, for example, from external corrugated profiles or external trapezoidal profiles in a subsequent process step. The present invention also relates to a method of preparing the twin-wall composite sheet.
|
