| 摘要 |
<p>PURPOSE:To enhance working efficiency and to uniformly apply a resin layer only on a necessary part, by preheating a base material tube of a straight tube state to immerse a part thereof in a resin tank having a resin received therein in a sol state and heating the immersed tube to allow the protective resin layer to gel before applying bending processing to said tube. CONSTITUTION:A primer material enhancing the close adhesiveness of a coating resin is applied on the surface of a base material tube 1 such as a zinc plated soft steel tube whose surface is coated with a fluorocarbon resin and the necessary part of the coated tube is preheated by a heating torch 2 and the heated tube is partially immersed in jet stream type coating resin tanks 3A, 3B. Since the base material tube 1 is preheated to the gelling temp. of the coating resin, protective resin layers 4A, 4B having sufficient thicknesses are formed only on the necessary part. By immersing the base material tube 1 under rotation, the thickness irregularity of the resin layers can be prevented. When this base material tube 1 is heated in a heating oven 5 having the gelling temp. of the coating resin, the resin is gelled and fixed. By applying bending processing to this tube, the tube is efficiently completed without waste of a material.</p> |
