Hose of impermeability and a process for manufacturing the same
A hose of impermeability has a wall corrugated along at least a part of its length, and formed by an inner thin resin layer, a laminated layer including a metal film, or a layer formed by a metal film, and an outer thin resin layer. It has a very high fluid impermeability owing to its wall layer including or formed by a metal film, and is also very flexible, capable of absorbing vibration, light in weight and strong. A tubular inner thin resin layer is formed by extrusion as the innermost layer of a multi-layered hose wall, and a laminated tape including a metal film, or simply a metal film is spirally wound or longitudinally lapped about the inner resin layer. An outer thin resin layer is formed about a layer formed by the laminated tape, or metal film, and the whole is at least partly corrugated. Alternatively, corrugation is done before an outer thin resin layer is formed by electrostatic powder coating. A different process includes applying a laminated tape including a metal film about a mandrel to form a tubular laminated layer, and after removing the mandrel, coating the inner surface of the tubular layer with a resin powder electrostatically to form a thin resin layer thereon.
1. A process for manufacturing a hose of impermeability comprising the steps of:
extruding an inner resin layer about a mandrel;
applying a laminated tape having a metal film held between two resin films to an outer surface of the inner resin layer to form a laminated layer; and
forming an outer resin layer about the laminated layer by extrusion or electrostatic powder coating to complete a multi-layered wall, and corrugating the wall along at least a part of its length, or
corrugating a hose structure composed of the inner resin layer and the laminated layer along at least a part of its length, and forming an outer resin layer by electrostatic powder coating about the laminated layer to complete a multi-layered wall.
2. A process for manufacturing a hose of impermeability comprising the steps of:
extruding an inner resin layer about a mandrel;
applying a metal film onto an outer surface of the inner resin layer to form a metal layer thereabout;
forming an outer resin layer on an outer surface of the metal layer by extrusion or electrostatic powder coating to complete a multi-layered wall;
each of the inner resin layer and the outer resin layer having a thickness not exceeding 5 mm; and
corrugating the wall along at least a part of its length.