| 摘要 |
PURPOSE:To manufacture a resin sheet with a fine irregular surface, which has a low friction coefficient and from which no frictional powder is generated, by bringing only one surface into contact with a cooling roll and cooling only the surface and forming fine irregularities having specific surface roughness to a surface not brought into contact in the melten sheet of a crystalline resin extruded from a mold. CONSTITUTION:A crystalline resin is used as a raw resin, and it is advantageous that high- density polyethylene and polyacetal are employed as such a resin. The raw resin is melted by an extruder, a molten resin sheet is extruded from a mold, and only one surface thereof is brought into contact with a cooling roll and solidified. Consequently, fine irregularities having center-line mean surface roughness of 0.2-3mum are formed to a sheet surface on the side not brought into contact with the cooling roll. The sheet surface brought into contact with the cooling roll is formed in a smooth surface. A pair of rolls such as nip rolls are used as the cooling rolls. Only both end sections of the molten resin sheet are brought into contact with a pair of each roll surface while only one surface of the molten resin sheet is brought into contact with the surfaces o the rolls at that time, the other surface of the molten resin sheet is brought to a free state not brought into contact with the rolles and the rolls are turned. |
