摘要 |
Disclosed are multilayer film structures having annular profiles, and methods and apparatus of making the structures disclosed. The annular multilayer articles have a uniform thickness, at least four layers and comprise overlapped and non-overlapped circumferential areas; wherein the layer structure of the non-overlapped area is doubled in the overlapped layer. A method of making the structure includes providing a multilayer flow stream with at least four layers of thermoplastic resinous materials; feeding the multilayer flow stream to a distribution manifold of an annular die to form an annular multilayer flow stream; and removing the annular multilayer flow stream from the annular die to form the annular multilayer structure. Also disclosed is an apparatus, comprising: a feedblock, with optional layer multiplier, that provides a multilayer flow stream of at least four layers to the manifold of an annular die; and an annular die having at least one distribution manifold that extrudes a multilayer flow stream. |
申请人 |
DOW GLOBAL TECHNOLOGIES INC.;DOOLEY, JOSEPH;ROBACKI, JEFF, M.;BARGER, MARK, A.;WRISLEY, ROBERT, E.;CRABTREE, SAM, L.;PAVLICEK, CALVIN, L. |
发明人 |
DOOLEY, JOSEPH;ROBACKI, JEFF, M.;BARGER, MARK, A.;WRISLEY, ROBERT, E.;CRABTREE, SAM, L.;PAVLICEK, CALVIN, L. |