TUBULAR PRODUCT, DEVICE AND METHOD FOR EXTRUSION Russian patent published in 2002 - IPC

FIELD: tubular product, method and device for extrusion of multilayer product. SUBSTANCE: multilayer product has at least three layers: a base layer, internal layer and a binding layer. The internal layer is made of plastic. The binding layer is positioned between the base and internal layers. The binding and internal layers badly stick together. The binding and internal layers are obtained by simultaneous extrusion of them on the base layer. The binding layer consists of foamed thermoplastic material at least in one intermediate layer. The internal and binding layers are simultaneously extruded inside the tubular base layer and pressed to it. The internal plastic layer and the binding layer are pressed to the tubular base layer by a diverging cone. The device for extrusion has a means for extrusion of a multilayer product and a diverging cone. The device is positioned inside the tubular base layer. EFFECT: balanced pressure acting on the device members, enhanced service life of the device. 14 cl, 10 dwg