Multilayer tubular structure with application in catheter manufacturing
This invention concerns a multilayer tubular body for the manufacture of catheter devices, which comprises an outer layer having certain mechanical properties and weldability, an inner layer with lubricious characteristics and forming at least one longitudinal lumen, and one intermediate bonding layer between the outer and inner layers. The intermediate bonding layer is, in cross-section, interrupted and in the form of spaced apart circular sectors, and the inner layer has on the inside portions which alternate with the sectors in the intermediate layer.
1 . A multilayer tubular body in particular for the manufacture of catheter devices, comprising an outer layer in a polymer with predefined mechanical and weldability properties, an inner layer in a polymer with lubricious characteristics and forming at least one longitudinal lumen, and an intermediate bonding layer between the outer and inner layers, wherein the intermediate bonding layer is, in cross section, in the form of circular sectors spaced between them, and the outer layer has on the inside parts which alternate with the sectors of the intermediate layer.
2 . Multilayer tubular body according to claim 1 , wherein the outer layer has internal protuberances extending longitudinally, the intermediate layer is discontinuous having spaced apart sectors, and the internal protuberances of outer layer are inserted into the gaps in the intermediate layer sectors.
3 . Multilayer tubular body according to claims 1 , wherein the outer layer has internal protuberances which alternate in turns with the gaps in the intermediate layer sectors, said internal protuberances and the intermediate layer sectors having the same thickness.
4 . Multilayer tubular body according to claim 1 , wherein the internal protuberances of the outer layer and the sectors forming the intermediate bonding layer run lengthways either parallel to or helicoidally to the axial of the body.