Extrusion International 3-2023

45 Extrusion International 3/2023 forklift truck via special feed rollers. The WEIMA ZM 40 four-shaft shred- der with a working width of approx. 760 mm first pre-shreds the filmma - terial to a homogeneous size. When changing the material, a built-in mechanism helps to ensure a partic- ularly fast screen change. The screen is guided on rollers and can be pulled out horizontally from under the shredder. In the next step, the shredded plastics are transported by a conveyor belt to the WEIMA WNZ 310/800 granulator, which granulates them to a size of approx. 6 mm. In parallel, a drum magnet ensures that any last metal residues are safely removed. Noise reduction during shredding and granulation Another reason for using a shredder with four-shaft technol- ogy is its low noise level of only about 76 decibels. At around 25 rpm, the ZM shredder dif- fers significantly from the WNZ secondary shredder, which ro- tates particularly fast at around 600 rpm and is correspondingly louder. To reduce the noise level of the WNZ as well, Fercell has completely enclosed the granula- tor in a soundproof box. It can be completely dismantled for main- tenance purposes. The recycling loop is closed Finally, the film flakes are filled into big bags by means of a suc- tion system and packed. Plasti- pack achieves a throughput of around 2,500 kg per hour. The regranulate is then used again in the actual production process of pool films. WEIMA Maschinenbau GmbH Bustadt 6-10, 74360 Ilsfeld, Germany www.weima.com Two-stage shredding for Plastipack with WEIMA shredders Conveyor technology between the pre-shredding and post-shredding of WEIMA General view of the WEIMA recycling plant at Plastipack