| 摘要 |
PROBLEM TO BE SOLVED: To simply obtain a tube of high quality by forming a non-bonding part to a part of the bonding surfaces of the inner periphery of a tubular article and the outer periphery of a metal core element before separating the tubular article from the metal core element. SOLUTION: A core element 1 formed by unifying two-split core elements 1a, 1b is vertically held by supporting both ends thereof so as not a shift the core elements 1a, 1b. Subsequently, polyamic acid is dissolved in a solvent to be polymerized to prepare a polyimide precurson soln. which is, in turn, applied to the upper part of the outer peripheral surface of the core element 1 by a spatula. A die is put on the upper part of the core element 1 to be allowed to naturally fall to bond the polyimide precursor soln. to the outer peripheral surface of the core element 1 in uniform thickness. Thereafter, the core element is heated and burnt to be formed into a film to form a tubular article. Fluoroplastic is applied to the surface of the tubular article formed on the outer periphery of the core element by spraying. |
