| 摘要 |
PURPOSE:To obtain a plastic fuel tank having excellent uniform extensibility and excellent impact-resistant strength even in the case of a thin wall thickness by making the tank from a high-density polyethylene resin composition having a specific R value and density, providing a baffle part at a specific size ratio and limiting a minimum wall thickness of the baffle part to the range of a specific ratio against its maximum wall thickness. CONSTITUTION:A plastic fuel tank is made from a high-density polyethylene resin composition wherein zero shear viscosity in a limiting viscosity of 2 to 6dl/g at 190 deg.C is 2X10<7> to 3X10<8> poises, an R value is 2.5 to 4, and density is 0.94 to 0.97g/cm<3>. The tank has a baffle part of L/D=2 to 5 (L denotes height and D denotes width at a position of a height of L/2), and a minimum wall thickness C of the baffle part is in a range of 0.65 to 0.95 against its maximum wall thickness E. The high-density polyolefin resin composition easily presents a curing phenomenon of the material, and blow-up is performed in a state that deformation of parison is made uniform at the curved parts of a mold, whereby a plastic fuel tank having a thicker wall thickness at the curved parts thereof can be formed. |
