Five Columns, Five Different Decisions

Here is the published FW-series data, reproduced exactly as it appears on the product page. Rotation speed is adjustable by frequency converter on every model.

Read casually, this looks like one machine in four sizes, and every column simply grows. Read carefully, the columns move at completely different rates, and each one answers a different question. Rotation speed rises 60 percent across the entire range. Capacity rises roughly four to five times. Drum diameter doubles. Power tracks both of those. Water use scales with the material the machine is asked to rinse. Treating the table as one growth curve is how buyers end up with a washer that is fast, powerful and still the bottleneck of the line.

Speed Is a Cleaning Setting, Not a Capacity Lever

The most counter-intuitive column is rotation speed. Across four models spanning 300 kg/h to 2,000 kg/h, the published speed window moves from 500 rpm to just 800 rpm. If throughput were a function of speed, the largest machine would need to spin several times faster than the smallest. It does not, because friction washing works by contact: the rotor and the plastic rub against each other, and that rubbing — its intensity, its dwell, its contact area — is what lifts oil, glue and soil off the flake surface.

Speed is therefore a cleaning setting, and the page is explicit that the exact setting depends on material, with capacity and water use varying alongside contamination level. Run the window too low and adhered contamination survives the pass; the machine rinses rather than friction-washes. The upper end of the window buys intensity for exactly the feed that needs it. And the column tops out at 800 rpm deliberately: beyond the window where friction cleans, more speed starts to abrade — fines go up, flake edges round off, the screen underneath works harder. Our friction washer guide covers how the mechanism works; the point here is narrower. The speed column is the one you tune, not the one you scale.

Diameter Is Where Throughput Comes From

Look instead at the drum diameter column: Ø500, Ø800, Ø1000, Ø1200. Capacity grows almost exactly with it — roughly four to five times from the smallest drum to the largest, while speed grew only 60 percent. Throughput in a friction washer is a volume question: how much flake the drum holds and works per revolution, how long each particle dwells against rotor and screen. A bigger drum answers that question; a faster motor does not.

Power is the column that follows the other two. From 15 kW on FW-500 to 55 kW on FW-1200, installed power grows with the larger, heavier drum, the greater mass of material inside it and the spray system that accompanies it — a consequence of the configuration, not a lever in its own right. Specifying a bigger motor onto a small drum does not wash more flake; it spins an underfilled drum faster, which is the abrasion regime the speed column avoids. The practical takeaway sits in the page's own selection points: match washer capacity to the upstream crusher so it does not become the bottleneck. The crusher sets the size and the rate of the stream; the capacity column is what you check against its output. Our crusher-to-washer article covers the size interface; the rate interface is the same conversation one column over.

Water Is the Carry-Away Budget

The water column moves from 2-4 m³/h on FW-500 to 8-12 m³/h on FW-1200, and like capacity it scales with the machine. Its job is different from the rest of the table, though, and the page is precise about the design: a friction rotor with replaceable paddles works the flake against a perforated screen, and high-pressure spray bars rinse the released contamination away. Friction lifts; water carries. The washer does not clean by soaking, and the water's assignment is to remove what the rubbing has detached before it re-deposits.

That is why the page ties water use to contamination level. Dirtier feed releases more material per kilogram of flake, so the same machine spends water faster to keep screen and flake clean — the range in each cell is the distance between a moderately dirty feed and a heavy one, not a tolerance. When you plan a line's water circuit, this column, not the capacity column, sizes your supply; and the wash water joins the line's closed-loop water system rather than running to drain.

One Washer or Three: the Cleanliness Target Decides

The FW page's own FAQ asks the question buyers should ask first: how many friction washers does a line need? The published answer is that small lines use one, larger or heavily contaminated lines use two or three in series, and the number is set by the cleanliness target for your output. Notice what that answer does not say: "buy a bigger model". Series configuration and model size solve different problems.

A bigger model solves a throughput problem: more flake per hour through the same cleaning process. A second or third washer in series solves a cleanliness problem: each pass re-works the flake surface, so contamination that survives one rubbing meets another. A line chasing saleable granulate from heavily soiled feed adds a stage; a line that doubled its crusher output moves up the table. Conflating the two is the most expensive mistake in this part of a line, because the wrong fix gets bought at the right capacity.

The page also names the precondition: material should be pre-crushed, typically to 10-30 mm. Too coarse reduces cleaning, because the rotor works surfaces rather than volumes; too fine complicates separation, because undersized particles behave differently on the screen and in the water. The window is part of the washer's specification, not a suggestion — which is why the crusher's screen choice is decided with this stage in mind.

What the Table Does Not Tell You

Three things sit outside the FW table, and each has a published answer on the same page.

First, temperature. For oily material, heated wash liquor improves results — and whether heat is needed for your feed is confirmed in a material test, not assumed from the polymer. The table covers the mechanical washer; heating is an arrangement around it, which is why the PET bottle washing line page lists hot washing as its own stage rather than a setting on the washer.

Second, the target of the friction. The page's FAQ names adhesive residue left after de-labeling as one of the main things friction washing removes, together with oil and soil. Glue is the contaminant rinsing cannot touch and friction can — it is the reason this stage exists at all, and our label removal article covers what happens upstream of it.

Third, position. The page places the FW series between crushing and float-sink separation, or between washing stages — after the crusher has opened the material and before the density stage sorts it, with dewatering further downstream. The washer works because it receives pre-crushed, wettable flake and feeds a density stage that expects washed, free-draining flake. Sizing the washer is really a conversation about that whole sequence.

Reading Your Feed Before Reading the Table

Because the published ranges are frames that the material fills in, the useful questions come before the model number:

• What is stuck to the flake? Oil, glue and soil are the three contaminants the page names, and each pushes a different variable — glue and oil toward intensity and possibly heated liquor, soil toward water use and series passes.
• How dirty, in tonnes per hour? The capacity column must match the upstream crusher; the water column must match the contamination level. Both cells are ranges for a reason.
• What does "clean enough" mean for your output? The number of washers in series is set by the cleanliness target for your output — pellet feed, bottle-grade flake and sellable regrind are different targets.
• Is your feed pre-crushed inside 10-30 mm? Outside that window, more speed or more water cannot recover the cleaning the page describes.
• Has the speed setting been confirmed on your material? A test run fixes the speed, the water rate and whether heat pays for itself.

Answer those five and the table stops being four machines in a row and becomes a selection: pick the row whose capacity matches your crusher, set the speed your contamination justifies, budget the water your feed will spend, and add stages until your cleanliness target is met.

Frequently Asked Questions