LTG low-temperature air-cooling mini-granulator for clean PE film

LTG low-temperature air-cooling mini-granulator for clean PE film

Most plastic pelletizing machines are bought by recycling plants. This one is not. The LTG is a mini plastic granulator sized for the factory that produced the scrap — a blown film or bag-making operation with its own offcuts, start-up waste and reject rolls piling up in a corner.

That changes every specification decision on the page. It runs on air cooling instead of water cooling, needs 2–10 m² of floor, and is built around a 15–55 kW inverter-driven extruder producing 30–180 kg/h. It is not a small version of a recycling line. It is a different machine for a different buyer.

Who this machine is actually for

The customer profile is unusually specific, and it is worth stating plainly because it is also the fastest way to tell whether this page is relevant to you.

The LTG is well suited to factories equipped with blown film machines and bag-making machines, where monthly PE film scrap — HDPE, LDPE or LLDPE — runs below 10 tonnes.

Put that figure next to the capacity range and the sizing answers itself. Ten tonnes a month is roughly 60 kg an hour if you run one eight-hour shift across a twenty-two day month — which lands squarely on the LTG75 at 30–60 kg/h. Scrap generation above that, and you move up the range rather than running the small machine longer.

What makes this buyer different from a recycling plant is that they already know exactly what their scrap is. It came off their own extruder an hour ago. It has no soil on it, no unknown polymers mixed in, no labels, no surprises. That single fact is what makes everything else on this page possible.

Air cooling, and what having no water changes

This is the hard dividing line between the LTG and every other pelletizing machine in the range, and it is worth understanding as a systems decision rather than a component choice.

Conventional pelletizing cools the melt with water. The moment water enters the process you have committed to more than a cooling method: you need a water supply, a trough or ring, a dewatering stage to get the water back off the pellets, somewhere for the dirty water to go, and floor space for all of it.

The LTG uses a low-power fan instead of water cooling to solidify the pellets, which reduces energy use and removes that entire branch of the line. No water in, no water to remove, no effluent out. That is the real reason a pelletizing machine can fit in 2–10 m² — not because the extruder is small, but because everything water would have dragged in with it is absent.

For a film factory this matters more than it would for a recycling plant. A blown film works usually has no water treatment, no drainage designed for process effluent, and no appetite for acquiring either just to recycle its own offcuts.

Feeding film is the hard part

Film is the most awkward thing you can ask an extruder to swallow. It has almost no bulk density, it is springy, and it bridges over the screw instead of dropping into it. A machine that cannot feed film consistently will not hold its rated output no matter how the extruder is specified.

Two features handle it. The hopper carries a pneumatic cutter that shears film into flakes before it reaches the screw, converting an unmanageable sheet into something with enough bulk density to feed evenly. And for factories whose scrap comes off the line still on the core, a support frame can be designed to allow rolled film to be fed directly — no separate shredding step, no handling the roll twice.

That second point is easy to skim past and is worth a moment: for a bag-making factory, reject rolls are a large share of the waste stream, and being able to put the roll straight onto the machine removes a whole materials-handling operation.

How the machine is put together

Plasticizing

An extruder — screw and barrel — melts the film at a low temperature and moves the melt forward toward the cutter. Temperature is held by an electrical heater and a cooling fan working together on the barrel, which is how a low process temperature is maintained rather than merely aimed at: the barrel can be actively cooled, not just heated less.

Pelletizing

A pelletizing cutter works in tandem with rotating blades, cutting the melt as it leaves the die. Cutting happens at the die face, which is why no strand bath is needed and why the whole cooling job can be handed to air.

Cooling and conveying

The fan does two jobs at once: it solidifies the pellets and conveys them to the discharge outlet, where they are collected in bags or containers. One air stream, two functions, and no transfer equipment between them.

Drive and control

An energy-saving motor optimised for low power consumption — typically 15–55 kW depending on capacity — with an inverter for speed adjustment. Every driven element on this machine, extruder, cutter and fans, is inverter controlled.

Three models, 30 to 180 kg/h

Three things in this table are worth reading rather than skimming.

The cooling side steps up before the extruder does. Going from the LTG75 to the LTG120, the fan count goes from one to three. Going from the LTG120 to the LTG150 it does not change at all — both run three fans of the same rating, and the extra output comes purely from the larger screw and motor. In other words the air system is already sized with headroom at the LTG120, and the cooling step change happens between the first and second model, not the second and third.

The cutter is the same across all three. One 0.75 kW inverter-driven cutting motor covers the whole range, which tells you where the energy actually goes on this machine: into melting, and into moving air. Cutting is almost free.

The screw diameter is the model number. LTG75 is a ⌀75 screw, LTG120 a ⌀120, LTG150 a ⌀150. Nothing hidden in the naming.

The filter column tells you how clean "clean" needs to be

There is one row in that table that says more about the intended application than any of the capacity figures: the screen changer on the LTG75 is "without / manual type", while the two larger machines carry a hydraulic one.

A melt filter exists to catch contamination before it reaches the die. Offering the smallest machine without one is only defensible if the feedstock is genuinely clean — which is exactly the premise of this product. In-house film offcuts have nothing in them to filter out.

Read the column as a statement of scope rather than a cost saving. If your scrap needs a hydraulic screen changer, it is telling you something about your material, and possibly that you need a washing line ahead of any pelletizer.

What "clean" means, and what to do if yours is not

This machine is specified for clean PE film. It is worth being precise about the boundary, because getting it wrong is expensive in a way that shows up in the pellets rather than in the machine.

Inside scope: HDPE, LDPE and LLDPE film generated in your own plant — edge trim, start-up purge film, reject rolls, bag offcuts. Material whose polymer you know because you bought the resin.

Outside scope: post-consumer film carrying soil, sand, product residue or moisture; mixed polymer streams; heavily printed material. Not because the extruder cannot melt it, but because there is no washing stage in front of it and no water in the process to compensate. Contaminated film needs a washing line first, and at that point you are building a recycling plant, not recycling your own offcuts.

The honest test is the one at the top of this page: did your own factory produce this scrap, and do you know what resin it is? If yes, this machine is the short answer. If no, it is the wrong machine and a bigger conversation.

Putting the pellets back into production

Pellets leave the machine through the discharge outlet into bags or containers, which for this buyer usually means straight back to the raw material store rather than out of the gate on a lorry.

That closed internal loop is the economic case. The factory is not selling recyclate into a commodity market at whatever the price happens to be that month; it is displacing virgin resin it would otherwise have purchased, at the resin price, in its own plant. Scrap that was a disposal cost becomes an input.

How much of the recycled pellet gets blended back into which product is a decision for your own process engineers and your own specifications — it depends on the article, and it is not something a machine specification can answer.

Frequently asked questions