| 摘要 |
PURPOSE:To prevent the surface of a plate from getting dirty by a method wherein recesses and protrusions are provided on the surface of a base plate, the surface of the protrusion is made larger than the same of the recess, a difference in the height of surface between the protrusion and recess is made within the range of 0.1-2mm and glass fibers, having fiber length longer than 3 times of straight length of the protrusion, are employed to make the unit plate. CONSTITUTION:A unit plate (a) is formed by a shallow box body provided with connecting rims 2, standing vertically to the four sides of a rectangular base plate 1. A material, constituting the unit plate (a), is unsaturated polyester resin containing glass fibers as reinforcing fibers and the glass fibers are chop strands having lengths of about 30mm. The glass fibers are contained in the resin by 10-50wt%. The base plate 1 is provided with check-like recesses and protrusions, which are divided into small sizes, on the whole surface thereof. In this case, the surface of the protrusion is made larger than the surface of the recess, a difference in height of surface between the protrusion and recess is made within the range of 0.1-2mm and the glass fibers, having the substantial fiber length of 3L or more, are employed to make the unit plate. Here, L means the maximum straight length measured along the surfaces of all of the protrusions. |
