| 摘要 |
Monofilaments of polypropylene or of mixtures containing a major proportion thereof with, e.g., polystyrene are produced by quenching the extruded filaments at room temperature in a bath spaced not more than 20 cm. from the extruder head, and thereafter stretching in three stages to a total stretching ratio of from 5,5-8,1, the extent of stretching decreasing at each stage and the intermediate stretching being effected at a temperature higher than that of the other two stages. Suitably, the monofilaments are first stretched at room temperature to a ratio of 3 : 5, then stretched in a water bath at just below 100 DEG C. to a ratio of 1,4 : 1,9, and finally stretched at room temperature to a ratio of 1,1 : 1,2. The monofilaments may be incorporated in, e.g., brushes and brooms. |
