| 摘要 |
<p>A device for introducing a fluid foaming agent into a plasticized polymeric material comprising, a conduit and a fluid permeable labyrinthian element interposed in the conduit for the passage of the plasticized polymeric material therethrough under pressure. Means for supplying fluid foaming agent to the fluid permeable element at a pressure greater than the pressure of the plasticized polymeric material so that the fluid foaming agent will flow through the element and into the plasticized polymeric material in a finely dispersed state.</p> |
