| abstract |
A flat and nearly mechanically isotropic polymer film or sheet (38), or a tube, can be formed by laminating two or more films, preferably by coextrusion of a liquid crystal polymer film and a thermoplastic polymer film. A liquid crystal polymer layer may be combined with one or more thermoplastic polymer layer in various arrangements. The liquid crystal, and possibly the thermoplastic as well, may have a controlled molecular orientation. The film (38) may be formed by passing a polymer through a set of two or three tubular rotors (32, 36) which are concentric and have facing surfaces which define inner and outer annular polymer flow channels. |