| 摘要 |
PURPOSE:To form a polyvinylidene fluoride film having uniform appearance on the entire inside of a metal tube by forming a molten polyvinylidene fluoride film on the inside of the metal tube, isolating the interior of the tube from the open air and cooling the tube to a temp. below the crystallization temp. of the polymer. CONSTITUTION:Polyvinylidene fluoride powder is adhered to the inside of a preheated metal tube such as a steel tube by sending under pressure, suction or other method and a perfectly molten polyvinylidene fluoride film is formed by heating to the m.p. of the polymer or above. Caps of asbestos cement or the like are fixed on both ends of the tube to isolate the interior of the tube from the open air and the tube is uniformly cooled to a temp. below the crystallization temp. of the polymer. A polyvinylidene fluoride film having uniform appearance is formed on the entire inside of the metal tube, no residual strain remains and blistering is prevented. |
