| 摘要 |
<p>Polyolefin articles with a shiny outer surface are produced by mixing the polymer under strong compression, extruding a parison into a mould, establishing a temp. gradient between the parison wall and the mould wall, the gradient being of such magnitude and applied during such time as to allow the surface of the parison to remain molten and prevent formation of crystalline aggregates, and finally applying the parison wall against that of the mould. M)thod may be used for prodn. of containers e.g., bottles. Besides having an attractive appearance, the prods. are also mechanically stronger than conventionally blow-moulded prods.</p> |
