| 摘要 |
<p>Filled polymer compositions, especially low-smoke-and-fume cable insulation compounds, are subjected to reduction in cross-section by shear flow in the solid state (plastic flow) in order to improve dispersion of the filler. The reduction ratio is at least 10:1 and the shear flow is maintained for at least 0.3 sec. Preferably the softening point is not exceeded, but if it is the exposure time is limited to one minute; no substantial excursion above the decomposition temperature of any ingredient is allowed. ''Conform'' extrusion is the preferred way of achieving the required flow.</p> |
