Wherever production takes place, residuals inevitably accrue. This is also the case at Plastipack Limited in the United Kingdom. The manufacturer of high-quality pool covers shreds and then recycles its plastic film waste in-house using a two-stage shredder from WEIMA – an excellent example of closed loop production.
It all started with a request to British WEIMA dealer Fercell from Aylesford in the county of Kent. Plastipack had already had positive experiences with recycling its own production waste for many years. Then added to that was an increased demand for pool covers. Consequently, the existing granulation system needed to be updated in order to further increase efficiency and throughput.
After extensive material tests at Fercell’s test center, the optimal configuration was finally developed, whereby Plastipack opted for a two-stage processing solution consisting of a pre-shredder and a secondary shredder, along with material handling technology.
Where recycling begins: the shredding system
Using a forklift truck, voluminous residuals from production can be fed into the generously dimensioned hopper via special in-feed rollers. The WEIMA ZM 40 four-shaft shredder with a working width of approx. 760 mm initially shreds the film material to a homogeneous size. Changing materials is supported by a built-in mechanism for particularly fast screen replacement. The screen is guided on rollers and can be pulled out horizontally under the shredder.
In the next step, the shredded plastics are transported via a conveyor belt to the WEIMA WNZ 310/800 granulator, where they are granulated to a size of approx. 6 mm. At the same time, a magnet drum ensures that any remaining metal residues are safely removed.
Another reason for using a shredder with four-shaft technology is its low noise level of only approx. 76 decibels. With around 25 revolutions per minute, the ZM shredder differs significantly from the WNZ secondary shredder, which rotates particularly fast at around 600 rpm and is correspondingly louder. In order to reduce the WNZ’s sound level, Fercell completely enclosed the granulator with a sound-reducing box. It can be completely dismantled for maintenance purposes.
Using an extraction system, the film flakes are in the end filled and packed into Big Bags. Plastipack achieves a throughput of around 2,500 kg per hour. The regranulate is then used again in the actual production process of pool covers. The recycling cycle closes.