When I compare central and beside-the-press granulators, I focus first on material flow, not simply machine price. A central granulator is generally better for a factory processing large volumes of similar or compatible scrap from several machines, while a beside-the-press granulator is usually better for immediate recycling of sprues, runners, and rejected parts at one molding or extrusion line. Central systems can offer efficient collection and centralized handling, but they require conveying, storage, and material-management planning. Beside-the-press units normally reduce transport and simplify closed-loop recycling, although their capacity and flexibility may be more limited.
You can find more information on our web, so please take a look.
The correct choice depends on scrap volume, material mix, layout, labor, noise control, cleaning frequency, and the value of recovered regrind. In this guide, I compare the two configurations, explain their advantages and limitations, and provide a practical selection framework for buyers evaluating a plastic granulator machine.
| Evaluation point | Central granulator | Beside-the-press granulator |
|---|---|---|
| Typical position | Dedicated recycling area | Next to the processing machine |
| Material source | Several molding or extrusion lines | One press or one production line |
| Material handling | Often requires collection and conveying | Usually direct and short-distance |
| Best operating model | Large, organized production flows | Immediate recycling of clean process scrap |
| Main risk | Cross-contamination and material logistics | Limited capacity or frequent cleaning between materials |
A central granulator gathers scrap from multiple machines and processes it in a designated area. This arrangement can make sense when a plant has a stable production schedule, predictable material streams, and enough floor space for collection bins, conveyors, or feeding equipment. It can also allow operators to supervise one larger system instead of several small units distributed throughout the factory.
Central processing may support more consistent downstream handling when the plant uses defined sorting and storage procedures. For example, the operation can separate clear, natural, black, and filled materials before grinding instead of mixing them at the point of generation. This is important because contamination can reduce the usefulness of regrind and may affect the appearance or mechanical performance of the next product.
A central installation may also be easier to connect with dust collection, metal separation, storage silos, or automated conveying. However, these benefits depend on the full system design rather than the granulator alone. I recommend evaluating the granulator, feeding method, discharge method, filtration, and controls as one material-recycling process.
The main disadvantage is material movement. Scrap must travel from production equipment to the central area, either manually or through a conveying system. Each additional handling step can increase labor requirements and create opportunities for material loss, labeling errors, or contamination.
A central machine also requires careful scheduling when different polymers, colors, fillers, or production grades are processed. The rotor, screen, chamber, and feeding path may need cleaning between incompatible materials. If a facility changes materials frequently, the time spent on cleaning and verification can offset some of the efficiency expected from centralized equipment.
Initial project cost can also be higher because the buyer may need bins, conveyors, electrical work, safety guarding, ventilation, and floor-space preparation. I would not compare only the purchase price of the granulator. The more useful calculation is the total installed cost and the expected cost per kilogram of usable regrind.
A beside-the-press granulator is installed close to the injection molding machine, extrusion line, or other scrap source. Sprues, runners, edge trim, and selected rejected parts can move directly into the granulator with minimal transport. This short path can simplify handling and help the operator return compatible regrind to the same production process.
Beside-the-press recycling is especially attractive for clean, known-material scrap. The operator can often identify the polymer, color, and production source immediately because the scrap remains near the machine that created it. This arrangement may reduce the risk of mixing materials compared with an uncontrolled shared collection area.
These machines are also useful when production lines run different materials or when a factory wants flexible, modular recycling. A company can add a unit to a specific press instead of redesigning the entire plant. For a smaller operation or a facility with limited infrastructure, this can make the project easier to phase and budget.
The main limitation is that one machine generally serves a limited production point. If several presses generate high scrap volumes at the same time, the plant may need multiple granulators, additional operators, or a separate central system for overflow. The total cost of several small units can exceed the cost of one properly engineered central installation.
Space around the press is another consideration. The buyer must allow room for loading, discharge, cleaning, access, electrical connection, and safe operator movement. A compact footprint is helpful, but it does not remove the need for safe access and maintenance clearance.
Frequent material changes can also be inconvenient. If the beside-the-press unit processes several colors or polymers, residual material may remain in the cutting chamber or discharge path. I advise buyers to confirm cleaning access, screen removal, rotor access, and the expected changeover procedure before selecting this configuration.
I would normally consider a central granulator when several production machines generate compatible scrap and the factory already has an organized collection route. It is also worth evaluating when the operation needs a larger throughput range, centralized dust management, or integration with storage and conveying. The system is more suitable when material sorting is controlled before grinding.
Beilun Tuojie contains other products and information you need, so please check it out.
Central equipment can be practical for continuous production environments, large molding departments, extrusion operations, and plants that have a dedicated recycling room. The buyer should still verify whether the scrap is clean and uniform enough for central processing. A large machine does not solve poor sorting or inconsistent feed preparation.
I would usually recommend evaluating beside-the-press equipment for clean sprues, runners, edge trim, and rejected parts that can be recycled immediately. It is often suitable for pilot lines, smaller production areas, frequent product changes, and factories that want to avoid long conveying routes. It can also be useful when each press uses a different material or color.
This configuration is less appropriate when scrap contains metal, excessive moisture, heavy contamination, or large irregular parts beyond the machine’s intended feed size. In those cases, the buyer may need pre-sorting, a separate crusher, metal detection, or a larger central preparation line. Feed material must always be matched with the rotor, cutting chamber, screen, and motor selection.
Start with polymer type, part geometry, moisture level, contamination risk, and the maximum feed dimensions. Different materials place different demands on cutting tools and screen design, so I would provide the supplier with representative samples or detailed photographs. For reinforced or abrasive materials, discuss knife material, hardening, maintenance intervals, and screen wear expectations.
Ask for a verified capacity range in kilograms per hour rather than selecting a machine only by hopper size. Motor power should be stated in kilowatts; for example, a quotation may list a 7.5 kW motor, but that figure alone does not prove the required throughput. I also recommend specifying the target screen opening in millimeters, such as 8 mm or 10 mm, because final particle size depends on the screen, rotor speed, feed condition, and material.
For every quotation, I request the supplier to state whether capacity is theoretical or based on a defined material and test condition. A meaningful comparison should use the same polymer, feed form, screen opening, and operating method. This avoids comparing a nominal figure from one supplier with a test result from another.
Noise control matters particularly when a beside-the-press machine is installed near operators. Buyers should request a measured sound level in dB(A), with the measurement position and operating condition clearly identified. Centralizing the equipment may make noise and dust easier to isolate, but it can also require a separate room and ventilation design.
Maintenance access is equally important. I check whether operators can safely remove the screen, inspect the cutting chamber, adjust or replace knives, and clear blockages without unnecessary disassembly. A supplier should also explain recommended spare parts, routine inspection points, and the procedure for confirming rotor balance after service.
One common mistake is choosing a central or beside-the-press layout before measuring the actual scrap flow. I recommend recording scrap type, approximate mass, peak generation periods, material changes, and current handling time for at least several representative production days. Even a simple log can reveal whether the plant has a steady central stream or several separate streams that should remain local.
Another mistake is ignoring contamination control. A granulator cannot reliably produce useful regrind from mixed materials unless the entire sorting process is designed for that purpose. Buyers should define labels, bins, color separation, metal control, and storage conditions before equipment delivery.
It is also risky to focus only on motor power or price. A lower quotation may exclude conveying, sound enclosure, dust collection, spare screens, commissioning, or operator training. I suggest requesting a complete scope of supply and identifying which items are included, optional, or supplied by the buyer.
At Beilun Tuojie, I approach granulator selection as a process-matching exercise. The central question is not simply whether a customer needs a crusher or plastic granulator machine, but how the equipment will receive material, cut it, discharge it, and return or store the regrind. We can discuss central and beside-the-press configurations according to material type, feed size, target particle size, layout, and operating method.
For an accurate proposal, I recommend preparing the polymer name, whether it is filled or reinforced, the largest scrap dimensions, estimated kilograms per hour, desired screen opening, working schedule, and available installation space. Photos of the scrap and a simple layout drawing can help clarify the application. Final specifications, production capacity, power, noise level, delivery schedule, and spare-parts scope should be confirmed in the formal quotation.
Central granulators are generally the stronger choice for organized, higher-volume plants with several compatible scrap streams and sufficient space for centralized handling. Beside-the-press granulators are generally the stronger choice for clean, traceable scrap generated at individual machines, especially when flexible installation and short material routes are priorities. Neither configuration is universally superior; the best option depends on the plant’s material flow and changeover pattern.
My recommended next step is to map each scrap source, separate compatible and incompatible materials, estimate peak kilograms per hour, and compare the complete installed cost of both layouts. Then ask Beilun Tuojie for a configuration review based on your samples, target particle size, available space, and recycling objective. This process gives buyers a more reliable basis for selecting a central system, a beside-the-press unit, or a hybrid arrangement combining both.
If you want to learn more, please visit our website Pros and Cons of Central Versus Beside-the-Press Granulators.