| 摘要 |
PROBLEM TO BE SOLVED: To provide a plastic panel with sufficiently high rigidity and strength to a large load. SOLUTION: A plastic panel 1 is a hollow double wall structure with one wall 2 and another wall 3 facing each other. A slit rib 5 with a ratio of the depth B1 to the width of an aperture A1 (B1/A1) of at least 1.5 is formed on a part of the one wall 2 toward the other wall 3. A rib expansion preventing part 6 with a shape wherein the bottom wall of the rib is continuously thickened in the aperture direction is formed on the slit rib 5. The ratio of the depth B2 of the shallowest site to the width A2 of the aperture of the rib expansion preventing part 6 (B2/A2) is made in the range of 0.05-0.7 of the ratio of the depth B1 to the width A1 of the aperture of the site with no rib expansion preventing part 6 of the slit rib 5. |
