| 摘要 |
<p>The cast or similar sheet of rubber or similar material is punched or drilled to the desired pattern and treated so that it expands by 2-15% esp. 4-8% above the frame dimensions esp. by swelling with a solvent. It is then fixed to the rim of the frame by adhesive, and the solvent driven off by evaporation heat or pressure, so that the material automatically shrinks and comes under tension. Esp. heat shrinking material is used.</p> |
