| 摘要 |
PURPOSE:To provide a bobbin made of foam synthetic resin which is excellent in light weight, impact resistance, size stability, foam uniformity, etc. CONSTITUTION:For a bobbin made of synthetic resin to be used for winding wire-shape material, the bobbin is formed by preparing material A comprising grain of polypropylene resin including carbon black by 0.05-0.2wt.% and foamed by a magnification of 1.05-1.5, and material B comprising polypropylene resin grain, and injection moulding mix of material 100 parts by weight comprising the material A by 5-45wt.%, and the material B by 55-95wt.%, to which foam agent is added, for providing an injection moulded product at a foam magnification of 1.05-1.5. |
