| 摘要 |
1,109,448. Ropes. IMPERIAL CHEMICAL INDUSTRIES Ltd. 18 Jan., 1966 [2 Feb., 1965], No. 1138/66. Heading D1T. A rope is formed from extruded stereoregular propylene drawn by at least 13:1 and in the form .of ribbons or filaments having a thickness of at least 0.003 inch, a number of these ribbons or filaments being twisted together to form a strand, and a plurality of said strands being twisted together to form a rope, the resulting rope having, for a standard 3 inch circumference rope, the following properties:- (1) a stretch resistance at 5,000 1bs load of at least 400 lbs per 1% extension; (2) a torque resistance of at least 50 in.-16 per revolution, per ton strand helix angle; (3) a creep after 120 repeat loadings to 75% of the breaking load of less than 15%; and (4) a breaking load of at least 7.75 tons.. The stereoregular polypropylene may be isotactic polypropylene. The material if in the form of filaments has a friction of at least 2 Ib; and if in the form of slit-films or ribbon filaments has a friction of 4.5 - 40 1b. |
