FLEXIBLE HOSE AND ITS PRODUCTION

Japanese Patent JP3779770

B2

PROBLEM TO BE SOLVED: To produce a flexible hose high in reliability without requiring post- finish by winding a spiral covering material around the outer periphery of a thermoplastic resin hose to insert the hose into an outer cylinder and sealing both ends of the hose to heat and sofen the same and applying internal pressure to the hose from the inside to cool the hose. SOLUTION: A spring 2 made of stainless steel is wound around the outer periphery of a thermoplastic resin hose 1 and the hose 1 is inserted into an outer cylinder 3 made of stainless steel in this state. Next, one end of the hose 1 is closed by a seal material 4 made of stainless steel and the other end thereof is also sealed by a seal material 5 made of stainless steel to be connected to a pipe 6. Next, a band heater 7 is applied to the outer peripheral part of the outer cylinder 3 to heat the outer cylinder 3. When the hose 1 is softened, the band heater 7 is turned off and, at the same time, air pressure is applied to the interior of the hose from the pipe 6. Thereafter, the band heater 7 is detached to cool the hose by water or air. When the temp. of the hose 1 approaches room temp., the hose is detached from the outer cylinder 3 and the spring 2 is detached to obtain a flexible hose.