PROCESS AND APPARATUS FOR REDUCING DIE DRIPS AND FOR CONTROLLING SURFACE ROUGHNESS DURING POLYMER EXTRUSION

摘要

Provided is a method of reducing the incidence of defects caused by die drool or die drips on extruded polymeric products such as films and sheets. The method includes the step of directing a flow of gas (15) towards the die (10). The flow of gas is substantially parallel to one or more surfaces of the extrudate (30), and the temperature of the gas is about 50°C to about 300°C when it impinges on the surface of the die. Moreover, selecting the temperature or flow rate of the gas provides a method of determining the surface roughness of the extruded polymer.