PROCEDUSE AND APPARATUS FOR MANUFACTURING OF MULTI-LAYER ARTICLES FROM ORCANIC POLYMERS

摘要

Improvements in the manufacture of multi-layer organic polymer composites are described, particularly applicable to composites including adjacent layers of a relatively water-soluble polymer (e.g. partially hydrolysed polyvinyl alcohol) and a relatively water-insoluble polymer (e.g. fully hydrolysed polyvinyl alcohol). The extruded layers are brought together within the die housing or by nipping means external to the die, or the relatively water-insoluble layer may be coated onto the relatively water-soluble layer. Specific designs of die are claimed, as are specific extrudable compositions and apparatus for conveying the same to the dies. The invention makes available for the first time a range of articles in which plastic parts are water-compatible in normal use but are completely degradable on contact with water during disposal, such as WC-disposable sanitary articles and water-degradable rigid containers for oil and petrol.