| 摘要 |
<p>The dimensional stability of a crystallisable cellulose acetate film is improved by heating for 15-65 secs. at 230-270 degrees C and rapidly cooling to below 210 degrees C. During this time the film is held under a lengthwise tension of is not >6.3 g/cm. The films are used especially as photographic support materials or as packaging films. The films are not thicker than 0.254 mm. They have a shrinkage, during 60 secs. at 240 degrees C, of is not 0.5%.</p> |
