| 摘要 |
<p>1,217,170. Carbon fibres. HITCO. 29 Dec., 1967 [20 Feb., 1967], No. 59211/67. Heading C1A. Carbon fibres having a high modulus of elasticity are prepared by resistively electrically heating to above 2000‹ C. a short span of a moving continuous strand or web of conductive, amorphous carbon fibres for up to 10 seconds in an inert atmosphere, and simultaneously stretching the fibres in the strand by 10 to 50% of their original length. Non-conductive fibres are preheated to between 400‹ and 1900‹ C. in an inert atmosphere either radiantly or resistively electrically, in order to render them conductive. The electrical heating is effected by passing the strand over electrodes, which are preferably of the roller type, so as to complete an electric circuit with the short span of strand or web. Additional systems of rollers are used to stretch the fibres during heating. The stretching may either be effected by applying to the yarn a constant force, or providing a constant stretch.</p> |
