| 摘要 |
PURPOSE:To continuously manufacture a long heat insulated pipe having a heat insulating foamed urethane layer and a plastic skin layer by a method wherein urethane stock liquid is uniformly expanded from the outer peripheral surface of the pipe main body to the inner peripheral surface of a tubular plastic skin layer during the running course of the pipe ranging from a L-type nozzle to a take-off unit. CONSTITUTION:A pipe main body 1, onto which urethane stock liquid 3 is adhered in a uniform thickness is inserted in a tubular plastic skin layer 2 at its center. After that, urethane stock liquid 3 adhered to the pipe main body starts to uniformly expand from the outer peripheral surface of the pipe main body 1 to the inner peripheral surface of the tubular plastic skin layer 2. After the plastic skin layer 2 is sized by sizing die 10 and cooled, the expansion of the urethane stock liquid reaches the plastic skin layer 2, and at the same time fills the inner peripheral surface of the plastic skin layer 2 and simultaneously hardens. The resultant heat insulated pipe covered with the foamed urethane layer 12 and the skin layer 2 is taken off by a take-off unit 6 locating ahead. |
