Polystyrene Extrusion Line In the process, polystyrene pellets, like those used to produce rigid sheet for thermoforming Polystyrene Extrusion LineIn the XPS process, polystyrene ... for thermoforming, are melted and blended in a regular tandem extrusion system. The extruders pump the melted material through a flat ... mature before it is ready for the finishing operation. Polystyrene Extrusion Line