MULTILAYER BATCH HAVING CONCAVE SURFACE Russian patent published in 2009 - IPC B29B11/10 B29C43/20 B29C69/02 B29B11/14 

FIELD: chemistry.

SUBSTANCE: multilayer batch in molten state having symmetry axis for producing multilayer articles by compression moulding. It includes first synthetic polymer and at least one thin layer of functional polymer, at least considerable portion of which is surrounded by synthetic polymer. Part of the surface is concave. The batch can have an orifice. The concave surface at least partially is an inner surface formed by the orifice. Multilayer article produced from the batch in molten state contains at least one area where thin functional layer forms a fold. The method of multilayer batch production in molten state, in which polymers forming batch, are extracted at the same time and coaxially, firstly in line direction, then in the direction of extrusion are modified to obtain concave surface.

EFFECT: appearance of barrier properties close to the symmetry axis on the square comprising at least 10% of the square of the article and enhancement of barrier properties of article due to central zone of article.

14 cl, 17 dwg