| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for extrusion molding for coating with a resin with straight grain pattern under stable condition and a steel pipe coated with the resin with straight grain pattern produced by the method for extrusion molding. SOLUTION: A thermoplastic synthetic resin mixed with wood powder and with good softening melt fluidity is mixed with black, brown, red and other multicolored heat-resistant pellets with a higher softening melt temp. than that of the resin and heating temp. at the front part from the central part in the heating cylinder of an extrusion molding machine is set in a range of 165-180 deg.C. In addition, a plurality of partitions for distributing the flow of the softening molten resin are provided in a molten resin flow path in a die and extrusion molding is performed while the same number of weld lines are generated in the resin flow. |
