| 摘要 |
Improved extruded synthetic polymer resin sheet structures are disclosed having optimized combinations of rigidity, light transmission, thermal insulation and sheet weight per unit surface area. These improved structures have rib structures where the shear modulus equivalent value ("G") is optimized and is in the range of from 0.5 to less than 8. In one embodiment, an average of from one to nine rectangular cells per every ten cells contain a diagonal rib. In a preferred embodiment there are two crossing diagonals located in alternating rectangular cells. The reduction in the number of diagonal ribs reduces the weight of the sheet (per unit surface area) but surprisingly does not cause a proportional reduction in the sheet strength and rigidity. |
