A crusher is usually bought on motor kW and price, with the rotor mentioned last. Yet the rotor is the only part that actually contacts the material. Two machines of identical power can behave completely differently on the same feed, and the difference is the tooth profile — whether the material is gripped at all, whether it is cut or hammered, and what shape leaves the chamber.

The three published profiles

LVKESORT's published specification states the application of each profile directly, which is rare enough to quote as-is:

Profile	Published application	Published characteristic	How it grips
V-shape	Film, woven bags	Fine output, high capacity	Pointed teeth pierce first, then shear
Stepped	Sheets, pipes, profiles	Strong crushing force	Progressive edges stack impact on shear
Flower	PET bottles, rigid plastics	High efficiency, easy blade change	Many contact points, fast passage

V-shape: the fix for film wrapping

Film and woven bags are light and soft. In the chamber they do not fall away from the rotor; they wrap around the shaft, tighten, and the throughput falls off while the motor keeps running. The V-shape teeth are arranged as a series of sharp angles on the rotor, forming a shearing edge as they turn. The point grips the material before the cut, so the residence time in the chamber is short, wrapping is limited and the output is fine — which is what "fine output, high capacity" describes.

On a film line, whether the rotor grips decides the day's output far more than whether the motor is 45 or 55 kW.

Stepped: how hard material gets bitten

Sheet, pipe and profile stock has thickness and rigidity. A pointed tooth skates across it; the material is pushed around the chamber instead of being cut. The stepped rotor uses progressive tooth edges so impact and shear act together, working into the material layer by layer — the published phrase "strong crushing force" is a description of that mechanism, not a marketing line.

The common misjudgement here is buying power to solve a gripping problem. Power provides torque and rotor speed; the tooth profile decides whether the rotor can hold the material at all. Given equal kW, a stepped rotor will cut thick sheet while a V-shape rotor skates on it.

Flower: throughput and the downtime bill

Bottles and rigid plastic parts do not need to be held for long; they need to pass through quickly. The flower profile puts many gripping points on the rotor, so bottle feed tumbles less and moves through faster — the source of "high efficiency".

The more practical feature is "easy blade change": blades are mounted individually, so a worn blade is swapped on its own instead of pulling the whole rotor. On a bottle flake line running continuously, two hours of downtime usually costs more than the blades themselves. That design trades maintenance convenience for running time — worth calculating, not just noting.

Matching the feed, including mixed feed

• Film, woven bags, agricultural film — V-shape.
• Sheet, pipe, profile stock — stepped.
• PET bottles, rigid plastic parts — flower.

Mixed feed is decided by the dominant stream. Where two streams are close in share and both matter, add sorting or manual picking upstream rather than expecting one profile to serve both. A profile forced to do both usually fails at both: film wraps, rigid stock skates.

Choosing the model: published numbers

Model	Rotor dia.	Power	Blades	Capacity	Feed opening
PS-300	Ø300	15 kW	9	150-300 kg/h	400×300 mm
PS-400	Ø400	22 kW	12	300-500 kg/h	500×400 mm
PS-500	Ø500	37 kW	15	500-800 kg/h	600×500 mm
PS-600	Ø600	55 kW	18	800-1200 kg/h	700×600 mm
PS-800	Ø800	75 kW	24	1200-2000 kg/h	900×800 mm

Source: published PS series specification. Capacity figures are ranges that depend on material; plan on the lower end and keep margin.

Rotor, gap, screen: the order of decisions

Three settings interact, and doing them out of order produces flake that meets the size spec but not the shape spec.

• Rotor profile sets grip and flake character.
• Blade gap decides whether material is cut or dragged. Published: gap is customisable. Wide gap means material squeezes through, capacity drops and flake quality suffers; narrow gap means blades wear each other.
• Screen aperture sets particle size: 3, 5, 8, 10 and 15 mm apertures, producing 5-20 mm output.

So the sequence is rotor by feed, then gap, then screen by target size. Choosing aperture first and matching a rotor afterwards tends to produce flake that measures correctly but cuts badly in the wash stage.

What makes a rotor last

Profile-to-feed match. Running a V-shape rotor on thick sheet puts continuous impact on the tooth edge; life shortens regardless of steel grade.

Gap. Too tight accelerates wear; too wide degrades output quality. Different feeds do not share one gap value, which is why gap customisation exists.

Upstream protection. Metal and grit damage the cutting edge directly. On most lines the better investment is not a more expensive rotor but a magnet upstream. The published spec is explicit that the crusher is not suitable for metal or stone.

Frequently asked questions