| 摘要 |
A multilayer plastic sheet of self-rollable material comprises at least two layers (2,4,6) of material joined to one another at states of different relative stretch and capable of alternating between a relaxed and a tensioned state and of inherently assuming a rolled-up configuration in said relaxed state as a result of the different states of stretch of the respective layers and to retain said inherent property of spontaneous rolling up even after prolonged exposure to sunlight and heat. A process for preparing a rollable sheet containing at least one layer of laminatable plastic material, said sheet being capable of alternating between a relaxed and a tensioned state and of inherently assuming a rolled up configuration in said relaxed state and retaining said inherent property of spontaneous rolling up even after prolonged exposure to sunlight and heat, comprises heating and stretching a first sheet of plastic material and laminating said first sheet of prestretched plastic material to a second sheet of non-stretched material, to form a self-rollable composite sheet. |
