| 摘要 |
PURPOSE:To prevent occurrence of cracks or blushing in a paint film by setting a heating means on a bending die to heat the painted film when a painted steel sheet is bent. CONSTITUTION:Every heaters 12-14 are always energized and every dies 2-4 are in a heated condition during bending. A painted steel sheet 8 is put on a fixed die 2 and a movable die 3 with the painted surface downward and is pressed to be fixed between the pressing die 4 and the fixed die 2. Bending of the sheet 8 is performed by upward turning of the movable die 3 by a cylinder 10 for the movable die. A painted film is such that a chemical conversion coating such as phosphate is applied to the surface of the sheet 8 and then a polyester coating is applied and baked. The elongation percentage of the paint film is larger as its temp. raises, so that the film follows bending of the sheet 8 and is easily elongated in the bending. By use of this bender, cracks or milking in the painted film accompanying bending are prevented.
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