| 摘要 |
1,145,728. Sintered PTFE/BN compacts. MONTECATINI EDISON S.p.A. 23 Jan., 1968 [24 Jan., 1967], No. 3394/68. Heading B5A. [Also in Division C3] A sintering is prepared by pre-forming a mixture comprising polytetrafluoroethylene powder in admixture with boron nitride powder in a compression mould at a pressure between 150 and 450 kg. per sq. cm. in the ease of a virgin powder or between 4000 and 6000 kg. per sq. cm. in the case of a recovery powder, sintering the pre-formed material by gradual heating in an oven up to between 300‹ and 400‹ C. for from 1 to 3 hours and gradually cooling the mixture in the mould under pressure. Preferably, the mixture contains about 10% of boron nitride by weight with respect to the polytetrafluoroethylene resin. |
