An agglomerator is a densification machine that turns light, fluffy plastic scrap — film, bags, raffia, stretch wrap — into dense, free-flowing granules using friction heat generated by high-speed rotating blades. Recyclers rely on it because loose film is nearly impossible to feed into an extruder and expensive to store or truck: baled film sits at roughly 20–50 kg/m³, while agglomerated granules reach 250–400 kg/m³ — a five- to tenfold gain in bulk density.
This guide explains how an agglomerator works step by step, which materials it handles, the specifications that decide real-world throughput, and where the machine belongs in a recycling line. The process descriptions and spec figures come from the film agglomerators we build and test-run at Energycle for PE and PP scrap.
Tabela de Conteúdo
- What is an agglomerator?
- How does an agglomerator work?
- What materials can an agglomerator process?
- Agglomerator vs. other densification machines
- Key specifications to check before you buy
- Where the agglomerator fits in a recycling line
- Agglomerators outside plastic recycling
- Perguntas frequentes
What Is an Agglomerator?
In plastic recycling, an agglomerator is a batch machine that densifies thin, lightweight plastics through friction. A set of fixed and rotating knives at the bottom of a steel tank spins at high speed; the friction between blades and material heats the plastic to its softening point — not its melt point — so the film shrinks and curls into compact crumbs. A shot of water then quenches the charge, and the crumbs solidify into irregular, popcorn-shaped granules of roughly 5–15 mm called agglomerate.
The same machine goes by several names: plastic agglomerator, film agglomerator, or densificador de filme plástico. The terms overlap, though “densifier” is also used more broadly for foam densifiers and screw presses. Agglomerate is an intermediate product: denser and far easier to convey, dose, and extrude than loose film, but not as uniform as finished pellets. You can see tank sizes, motor options, and typical outputs on our aglomerador de filme plástico product page.
Principais conclusões: An agglomerator is a friction densifier. All process heat comes from the main motor through the blades — there are no external heaters to install, power, or maintain.
How Does an Agglomerator Work?
An agglomerator works in repeating batch cycles. Each cycle takes about 8–15 minutes depending on the material, its moisture level, and the motor size. The operator — or a PLC on automated units — runs five stages:
- Loading. Film, bag, or raffia scrap enters the tank from the top, by hand or conveyor. Oversized pieces such as jumbo bags are shredded first so they tumble freely.
- Friction heating. The bottom rotor accelerates the charge against the fixed knives. Friction raises the temperature toward the polymer’s softening range, and the film begins to shrink and ball up.
- Densificação. As the crumbs compact, the drive motor’s current climbs. The ammeter reading is the operator’s main process signal — a steady amp rise means the batch is densifying on schedule.
- Shock cooling. At the target amp reading, a measured shot of water sprays into the tank. The sudden quench — accompanied by a burst of steam — freezes the crumbs and fractures them into granules.
- Conditioning and discharge. The blades keep cutting briefly to even out granule size, then the discharge door opens and the agglomerate exits, ready for bagging or the next process.
Because the process stops short of full melting, the polymer sees less thermal stress than in an extruder pass. The trade-off is granule shape: agglomerate is irregular by nature, which is why lines that sell finished pellets still run an extruder after the agglomerator.
What Materials Can an Agglomerator Process?
Agglomerators are built for plastics too light or too thin to feed into other equipment. Typical feedstocks:
| Material | Common forms | Processing notes |
|---|---|---|
| Filme LDPE / LLDPE | Stretch wrap, shrink film, carry bags | The reference feedstock — shrinks readily and densifies fast |
| Filme HDPE | Grocery bags, can liners | Runs hotter; quench timing matters to avoid over-melting |
| PP raffia and woven bags | Cement bags, FIBC / jumbo bags | Pre-shred oversized bags for even tumbling |
| Filme BOPP / CPP | Packaging and lamination film | Densifies well; watch for print and coating content |
| PP non-woven fabric | Meltblown and spunbond offcuts | Low bulk density feed benefits most from agglomeration |
| filme agrícola | Mulch and greenhouse film | Wash and dry first — sand accelerates blade wear |
Two exclusions matter. Rigid plastics belong in a granulator, not an agglomerator. And PVC film is a poor candidate: it degrades near its softening range and releases corrosive gas. Wet film straight out of a washing line should be dewatered first — the water load otherwise extends every cycle. For badly tangled or oversized input, a triturador de filme plástico ahead of the agglomerator keeps batches consistent.
Agglomerator vs. Other Densification Machines
Five machine types compete for the same broad job — making light plastic scrap dense enough to handle. They are not interchangeable:
| Máquina | Princípio de funcionamento | Saída | Where it wins |
|---|---|---|---|
| Aglomerador | Batch friction heating + water quench | Dense irregular granules, 250–400 kg/m³ | Low-cost densification of film and raffia before extrusion |
| Granulador | Rotary knife cutting, no heat | Flakes / regrind | Rigid plastics; thin film tends to wrap the rotor |
| Cutter-compactor | Continuous friction pot feeding an attached extruder | Compacted feed direct to the screw | Integrated one-step film pelletizing lines |
| Screw press densifier | Mechanical squeezing | Dewatered, semi-dense plugs | Very wet film coming off washing lines |
| Peletizador | Full melt, filtration, and cutting | Uniform 2–5 mm pellets | Producing a sellable, trade-grade pellet |
The agglomerator occupies the middle ground: more densification than a granulator can offer on film, far less capital than a full pelletizing line. The granulator-or-agglomerator call for film waste is covered in detail in our granulator vs. agglomerator comparison. For a deeper three-way analysis of the densification options, see our comparison of the film agglomerator vs. film compactor vs. screw press densifier.
Key Specifications to Check Before You Buy
Capacity claims mean little without the motor and tank dimensions behind them. These are the three film agglomerator models we build most often, and the numbers buyers should verify on any quote:
| Modelo | Capacidade | Potência do motor principal | Tank diameter | Tank height |
|---|---|---|---|---|
| ERM-AG-200 | 100–150 kg/h | 37 kW | 500 milímetros | 1200 milímetros |
| ERM-AG-500 | 250–350 kg/h | 75 kW | 600 milímetros | 2800 mm |
| ERM-AG-800 | 500–600 kg/h | 110 kW | 675 mm | 3800 mm |
Swipe to see full specifications →
Beyond the headline numbers, five details separate a machine that runs for years from one that disappoints:
- Energy per kilogram. Expect roughly 0.2–0.25 kWh per kg of film. If a quoted capacity implies much less, the figure is optimistic.
- Blade steel and access. Knives in D2/SKD-11 grade tool steel hold an edge through abrasive feeds; quick access for sharpening cuts downtime.
- Water dosing control. A solenoid valve with timer gives repeatable quenching; a manual bucket does not.
- Discharge design. A pneumatic discharge door empties the tank in seconds and shortens every cycle.
- Safety interlocks. Lid switches and rotor braking are non-negotiable on a machine with exposed high-speed knives during maintenance.
Where the Agglomerator Fits in a Recycling Line
Plants position agglomerators in three typical layouts:
- After washing and drying. In post-consumer PP and PE film recycling lines, the agglomerator densifies clean, dry flake so the downstream extruder receives a stable, meterable feed.
- Standalone for clean scrap. Converters and packaging plants with clean post-industrial film often run a single agglomerator and sell the agglomerate itself.
- Upstream of pelletizing. Agglomerate feeds a single-screw máquina de peletização de plástico far more steadily than loose film, raising extruder output and cutting feed-section bridging.
The economics rest on bulk density. Moving from 30 kg/m³ film to 300 kg/m³ agglomerate means one truck does the work of ten, and silo or gaylord storage shrinks in proportion — the arithmetic is laid out in our LDPE film densification and bulk density guide.
Agglomerators Outside Plastic Recycling
The word “agglomerator” also names unrelated equipment in other industries, which explains some confusing search results. Mining and fertilizer plants use rotary drum and pan agglomerators to bind fine powders into pellets for heap leaching or granular products. Food and pharmaceutical producers use fluid-bed agglomerators to make powders dissolve faster. Diesel fuel systems use filter agglomerators that coalesce water droplets out of fuel. ScienceDirect’s engineering overview covers those process-industry designs; everything else on this page concerns the plastic recycling machine.
Perguntas frequentes
What is an agglomerator machine?
An agglomerator machine is a batch densifier for plastic recycling. Rotating knives inside a steel tank heat film, bags, or raffia by friction until the material shrinks into crumbs; a water spray then quenches the batch into dense, free-flowing granules called agglomerate.
Does an agglomerator need external heating?
No. All heat comes from friction between the blades and the material, powered by the main motor. That is why motor size — 37 kW to 110 kW on our range — is the specification that actually sets throughput.
Can agglomerate be used directly, or does it need pelletizing?
Agglomerate is an intermediate product. Most processors extrude and pelletize it to get uniform, trade-grade pellets. Some thick-walled molding applications accept agglomerate directly, but only where feed uniformity is not critical.
What is the difference between an agglomerator and a granulator?
A granulator cuts plastic cold into flakes and adds no density — it suits rigid parts. An agglomerator heats and quenches thin film into granules five to ten times denser than the input. Thin film also tends to wrap a granulator rotor, which is exactly the problem the agglomerator avoids.
How much does an agglomerator machine cost?
Price depends on capacity, motor size, blade configuration, and automation level. A 100–150 kg/h unit costs a fraction of a complete pelletizing line, which is why many plants start with agglomeration. Send us your material type and target throughput and we will quote a specific model.
Are an agglomerator and a densifier the same thing?
In film recycling the two words usually describe the same machine. “Densifier” is the broader term, though — it also covers foam densifiers and screw press densifiers, which work on different principles.
A linha de fundo
An agglomerator solves one problem extremely well: it makes light, unmanageable plastic film dense enough to store, ship, and extrude — without the cost or complexity of a full pelletizing line. If your scrap stream is PE film, PP raffia, or non-wovens and your extruder starves on loose feed, agglomeration is usually the highest-return first step.
Tell us your material, current bale density, and target throughput, and our engineers will size the right model — or tell you honestly if a different machine fits better. Request a configuration and quote.
