| 摘要 |
PURPOSE:To easily form even hollow materials having inwardly sloped shoulders, having high strength in the vertical direction and uniform thickness, without failure of molding due to pinholes by a method in which a cylindrical body, shoulders, and a hollow material are integrally formed, a notch is formed from the fixed portion of the hollow part to the shoulders, and both end portions are bonded and the shoulders are shaped into a horizontal or inwardly inclined form. CONSTITUTION:An integral body of a bellows part 1, shoulders 2, and fixing parts 3 is formed of plastics by a blow molding method. In this case, the shoulders 2 are shaped into an inclined form toward the opening, the fixing parts 3 are shaped into an uprising form, and projections 4 are formed on the four corners of the shoulder. The projections 4 are cut off to form small holes 5, notch 6 is formed from the fixing part 3 to the shoulder 2 until the small hole 5 is reached. The notched portions are mutually overlapped and bonded to make the shoulder 2 horizontal to obtain an annular bellows body having horizontal shoulders 2. When the shape of the shoulder 2 is inclined into the bellows body 1, the overlapping portions of the notch 6 are enlarged.
|
