| 摘要 |
<p>A method of producing an extruded plastics foam of enhanced physical strength which comprises: (a) intimately mixing a blowing agent incorporating CO2 and in which the major proportion is a natural gas, in a plastics resin melt to form an homogeneous resin mix; and (b) extruding the resin mix through an exit die into a region of lower pressure; wherein the temperature of the resin mix is adjusted so that it is below the critical temperature (as hereinbefore defined) at the point of extrusion out of the exit die.</p> |
