| 摘要 |
<p>Process gives rise to a local effect. In particular, the plastic material, e.g. of PVC is in tubular form and the area(s) for which increased rigidity is required is immersed for at least 7 hrs. at ambient temp. in solvent e.g. CHCl3 capable of extracting plasticiser from the plstic. The treated plastic is then subjected to water vapour (120 degrees C) extraction. The operations are repeated until desired rigidity or hardness is achieved.</p> |
