| 摘要 |
<p>Cushions, mattresses, etc. are produced in foam, esp. a polyurethane foam, inside which springs are fitted, and they are packed for transport and storage under vacuum. For this purpose they are enclosed in an envelope of plastic, flexible material, which is heat welded along its edges. When the envelope is opened by the user, the cushions, etc recover their dimensions and elasticity due to the infiltration of air. The procedure brings the articles to the smallest possible dimensions and thus facilitates and cheapens storage and transport.</p> |
