摘要 |
<p>HB polymers, such as copolymers of hydroxy butyric acid and hydroxy valeric acid, are provided as melt extruded films having a thickness of 5 to 200 mu m. Sheet materials may consist of such a film or the film may be laminated with other films to increase strength or impermeability. The films are best made by co-extrusion with a thermoplastic that is substantially non-tacky upon solidification. The sheet materials are of particular value as diaper backsheets and ostomy bags. They may include a layer of non-woven material.</p> |