High-speed friction washer

In a plastic recycling line, the purpose of a friction washer is to scrub contamination off plastic flake mechanically. A shaft and paddles turning at 720–1200 rpm rub the material against itself and the machine wall while water sprays in from above to flush the loosened dirt away. It cleans surfaces without heat or chemicals, and it conveys the cleaned flake to the next stage.

Anything that needs mechanical action rather than time. In a plastic washing line, a soak tank lets water do the work at its own pace; a friction washer applies direct rubbing at speed, which shifts adhering soil, dust, loose fluff and surface residue that would still be attached after soaking. What it cannot shift is bonded adhesive and oil, which is what the hot chemical stage is for.

So that one machine both cleans and conveys. In a plastic recycling line the inclination means each rotation of the paddles moves flake upward as well as scrubbing it, delivering cleaned material to the next processing stage without a separate conveyor. That removes a drive, a transfer point and a length of floor from the layout.

Continuously, sprayed in from the top of the machine while it runs. In a plastic washing line this is a flow-through process rather than a soak: water enters at the top, carries loosened dirt and contaminants down and out, and flake climbs the other way. Consequently flake leaves this stage wet by design, with water removal handled by the dewatering machine that follows.

Duty. The inclined machines, mounted at 20° to 30°, clean and convey plastic flake in one pass. The heavy-duty horizontal friction washers are built specifically to rub paper labels off plastic surfaces, where the job needs sustained contact time rather than lift. Choose the horizontal machine if your feedstock is labelled bottles or printed containers.

The range is HSW350 at 15/22 kW with a 350 mm rotor, HSW450 at 30/37 kW with a 450 mm rotor, and HSW650 at 45/55 kW with a 650 mm rotor. All three run at 720–1200 rpm. Because the speed is common across the range, the larger rotors reach a higher tip speed and scrub harder as well as handling more material. Specify the higher motor rating of each pair for heavy or heavily soiled feed.

After size reduction and among the wet stages of a plastic washing line, feeding whatever comes next — a sink-float tank, a hot wash tank, a rinse stage or a dewatering machine. Many lines use more than one at different points, because the first pass on dirty incoming material and the final polish before drying are different jobs even though the machine is the same.

In a plastic recycling line, water is specified for the washing line as a whole rather than for the friction washer on its own: a PP and PE film washing line is rated at 4–5 m³/h at 200–300 kg/h, 8–10 m³/h at 400–600 kg/h, 15–20 m³/h at 800–1,000 kg/h and 20–30 m³/h at 1,500 kg/h. Four stages draw on that supply — the wet crusher, the friction washer, the sink-float tank and the high speed friction washer — with the screw loader moving flake on in water as well, and no split between them is published, so a line figure divided by the number of machines is not a per-machine figure. What the line figures do show is that the material decides: a rigid-plastics line at 800–1,000 kg/h uses 6–8 m³/h against 15–20 m³/h for film at the same throughput, roughly two and a half times as much, because film arrives carrying field sediment, mud and sand that has to be flushed out rather than merely rinsed off. Budget water from the line you are buying and the material you will feed it, not from the machine on its own.