| 摘要 |
PURPOSE:To prepare a resin coated perforated plate having a resin coating of which a surface is smooth by subjecting the perforated plate to the extrusion coating by using an extruder having a long die lip and a large volume resin sump for keeping a resin pressure to a definite level or less. CONSTITUTION:A length of the die lip L is set to a dimension sufficiently longer than a diameter of a hole 2 of the perforated plate 1 and the large volume resin sump 5 is formed to surfaces 3a, 4a of a metal mold and, in this condition, a molten resin 9 is sent into the resin sump 5 from the extruder through a manifold 6 and a restrictor 7 equalizing a resin stream. The resin is coated on a surface of the perforated plate 1 while a transfer speed of said perforated plate and an emitting amount of the resin are controlled so as to keep a resin pressure to a definite value or less. Becasue the die lip L is long, the resin filled in the hole 2 is solidified in an apparatus and prevented from being flowed downwardly. Because the resin is coated under a definite pressure or less, the resin in the hole 2 is not expanded after coating and a surface thereof is made smooth. |
