The REIfill technology required for this process is not a new development, but was obviously ahead of its time when it was introduced some years ago. However, against the background of continuously rising raw material prices, the interest in this sophisticated technology is noticeably increasing today. Over the past few months, Reifenhäuser Extrusion has sold several REIfill lines with a production capacity of more than 1500 kg/h per line. Great interest in this technology exists in Southern Europe, Russia, Asia and the Arab countries.
Processors can replace up to 40 percent of polypropylene and polystyrene with cost-effective mineral fillers such as calcium carbonate and talc by using the REIfill technology. The savings potential is enormous since the price of calcium carbonate is just one fifth of the current polystyrene price. While the resulting price advantage is eliminated in part with conventional single-screw extruders able to process expensive compound material only, the REItruder allows to fully utilize this advantage since fillers in powder form can directly be fed into the co-rotating twin-screw extruder.
In addition to cost-related aspects, the adding of mineral fillers - according to the application of the end product - is also of interest with regard to the product properties: filled polypropylene and polystyrene films have a higher stiffness compared to pure polypropylene and polystyrene films with identical wall thicknesses - an ideal prerequisite for the production of disposable dishes.
Producers whose products do not require such enhanced stiffnesses may reduce the film thickness resulting in further raw material and costs savings.
Furthermore, filled thermoforming sheets can be produced in many cases - depending on the end product - at increased cycle rates.