Patent ID: 6692804
Filing Date: 2004-02-17
Classification: B29C,Y10T

Abstract:
An extruded tubular article having a solid tubular wall portion, said wall portion comprising:a composite of at least two adjacent simultaneously extruded solid layers of thermoplastic flexible chain polymer, said extruded solid layers further comprising: at least one inner solid layer wherein a substantial number of polymer molecules in said layer form a helical pattern aligned at a first average angle with respect to a plane perpendicular to the longitudinal axis of the tubular article; at least one outer solid layer wherein a substantial number of polymer molecules in said outer layer form a helical pattern aligned at a second average angle with respect to said plane and wherein said first and second angles are different; and wherein said first and second angles are formed by subjecting said inner and outer layers to independent shear forces exerted by independently driven rotating surfaces.