Delta Kunststoffe, a producer of plastics based in Weeze, Germany, currently utilizes Coperion’s ZSK MEGAvolume PLUS twin screw extruder to produce electrically conductive polymer compounds, including polyamide 6, polystyrene, polyethylene and polypropylene.
The extruder is fitted with 76 mm diameter screws and it mixes conductive carbon black into the earlier molten base polymer. The ZSK MEGAvolume PLUS compounding system manufactures polymer compounds with a carbon black content ranging from 15% to 40% and its productivity varies between 1,000 and 1,500 kg/h. The screws include mixing components that uniformly distribute the carbon black inside the polymer matrix, thus helping to achieve the required conductivity of the final product. The screws allow downstream metering of the carbon black into the melt through a ZS-B twin screw side feeder. The melt in the process stage is efficiently degassed by using a twin screw side devolatilization unit. The compounding system’s large free screw volume significantly reduces cut on the product. The ZSK 76 MEGAvolume PLUS compounding system is chosen for its extremely high economic efficiency and ability to produce constantly high quality products. Other major reasons to select the twin screw extruder include low energy, maintenance and repair costs, low personnel costs for the system operation and profitable output/capital cost ratio.
The German company decided to use the ZSK 76 MEGAvolume PLUS system after extensive testing at Coperion’s laboratory. The testing revealed that when the polymer compound is filled with a particular type of carbon black with a density varying between 16 and 20%, the electrical resistivity in the material will be decreased by up to12 powers of ten. This is referred to as the percolation effect.