| 摘要 |
PURPOSE:To impart various patterns along with the lining of polyethylene by consistent lining by applying patterns to the outside of the corrosionproof polyethylene layer formed to the outside of a steel material using polyethylene layers having different hues. CONSTITUTION:A primer layer 2, an adhesive polyethylene layer 3, a corrosionproof polyethylene layer 4 and a decorative polyethylene layer 5 are applied to the surface of a steel material 1. The corrosionproof polyethylene layer 4 is formed by a method wherein 1.5-3.0% of carbon black is mixed with gaseous phase polyethylene in order to enhance weatherability to be kneaded therewith at high temp. under high pressure and the resulting mixture is processed into pellets to be finely ground by freeze- grinding to obtain a spherical polyethylene powder having a mean particle size of 100-400mum and this powder is subjected to electrostatic painting. The decorative polyethylene layer 5 is formed by mechanically mixing a pure polyethylene powder and a polyethylene powder high in the concns. of C, B and scattering and lining the resulting mixture under a heating condition. By changing the compounding ratio of the polyethylene black powder containing C, B and the polyethylene white powder, various hues are imparted to the decorative polyethylene layer. |
