How tyre recycling machine throughput changes with tyre size

How Tyre Recycling Machine Throughput Changes with Tyre Size

Tyre size is one of the first variables to examine when estimating the realistic throughput of a tyre recycling machine. It affects much more than the opening size of the shredder. Passenger-car tyres, truck tyres and large off-the-road (OTR) tyres behave differently during feeding, cutting, steel separation, conveying and granulation. A line rated for a certain hourly capacity may perform well on a steady passenger-tyre feed, then slow noticeably when the incoming material shifts toward larger, heavier or more heavily reinforced tyres.

For technical evaluation, the useful question is not simply “How many tonnes per hour can this machine process?” It is: “What tyre mix can the complete system process continuously, at the required output size, without creating a bottleneck?” That distinction prevents many specification mistakes.

Why larger tyres do not translate neatly into higher tonnage

A truck tyre weighs more than a passenger tyre, so it is tempting to assume that a shredder will achieve higher tonnage per hour when fed with truck casings. In practice, the result depends on the cutting mechanism and the downstream line. Larger tyres may increase the mass entering the machine per piece, but they also require more cutter engagement time, higher torque and more energy to shear the rubber-and-steel structure.

Truck tyres commonly have thicker tread, stronger bead bundles and a more robust carcass than passenger tyres. These features are valuable in service, but they place a heavier intermittent load on the primary shredder. If the machine uses automatic reverse logic to protect its drive during high-torque events, each reverse cycle reduces net throughput. This is not necessarily a fault; it is often the correct protection response. But it should be included in capacity calculations.

OTR tyres create a different problem again. Their diameter, width and bead construction can exceed the practical feed envelope of standard equipment. Even if a primary shredder has sufficient motor power, the tyre may require pre-cutting, bead removal or a dedicated tyre shear before it reaches the shredder. In that situation, the total line throughput is governed by the slowest preparation stage rather than the nominal shredder rating.

The four places where tyre size changes line capacity

1. Feeding and material presentation

Passenger tyres are usually easier to load into a hopper, belt conveyor or automated feeding arrangement. Their dimensions are relatively consistent, which helps maintain a stable feed rate. A mixed stream of passenger and light-truck tyres can often be handled with modest feed controls, provided the hopper opening and conveyor load rating are appropriate.

Large truck tyres can bridge across a hopper or sit awkwardly on a conveyor if the equipment was designed around smaller tyres. The consequence is not only reduced feed speed. Unstable presentation can cause uneven cutter loading, more manual intervention and unnecessary idle time. In a real plant, a machine running empty for short intervals can lose more productive capacity than expected from the specification sheet.

2. Primary shredding load

Primary shredding is where tyre diameter and reinforcement become most visible. The machine must grip the casing, draw it into the cutting zone and shear it into strips or chips. For a tyre recycling machine, cutter geometry, shaft spacing, hydraulic pusher force, drive torque and control settings matter at least as much as installed motor power.

A line intended mainly for passenger tyres can be configured for faster cutting and smaller output pieces. A line built around truck tyres may need more aggressive torque reserve and a coarser primary cut to remain stable. Trying to force the same small chip size from every tyre category at the first stage often sacrifices capacity and accelerates cutter wear. It is usually better to decide which size reduction belongs in the primary stage and which belongs in the granulation stage.

3. Steel handling and separation

Tyres contain bead wire, steel belts and textile reinforcement, but the quantity and form of these materials change with tyre category. Larger tyres generally introduce thicker and tougher steel components. Oversized wire bundles can wrap around shafts or overload downstream screens if the primary shred size is not suitable for the separation system.

Magnetic separators are effective only when the feed is appropriately liberated. If rubber chips remain too large or steel remains tightly embedded, separation efficiency may fall and recirculation loads may rise. That can make the granulator, rather than the shredder, the limiting machine. Evaluators should therefore assess the entire path from primary shredder to magnetic separation, fiber removal and final screening.

4. Conveyor and storage design

Tyre size also changes bulk density after shredding. A conveyor carrying loosely cut truck-tyre strips behaves differently from one carrying compact passenger-tyre chips. Large, irregular strips occupy substantial volume and may not flow consistently through chutes, bunkers or metering equipment. This is why a line can appear adequately sized on paper yet suffer from repeated material accumulation between stages.

A practical layout allows enough buffer capacity between major machines to absorb short variations in feed. It should also provide access points for removing steel bundles or non-tyre contaminants without stopping the entire system for an extended period.

A more useful way to define throughput

When comparing equipment proposals, ask suppliers to state throughput against a defined feedstock. “Mixed waste tyres” is too broad to support a reliable decision. The evaluation document should identify tyre categories, approximate diameter range, whether rims are excluded, expected contamination, moisture conditions, target chip or granule size, and the intended operating hours.

It is also sensible to distinguish between instantaneous capacity and sustained capacity. A shredder may process a few large tyres quickly when the cutters are sharp and the hopper is full. Sustained production includes feeding delays, reversing cycles, steel removal, screen changes, maintenance access and the behavior of downstream machines. The sustained figure is the one that matters for production planning.

Do not select the shredder in isolation

A tyre recycling project is often assessed as a chain of mechanical loads. Primary shredding, secondary shredding, granulation, steel separation and rubber finishing need compatible capacities. If the primary machine is oversized while the granulator is marginal, the plant will accumulate material and operators will reduce the shredder feed. If the primary shred size is too coarse for downstream separation, the apparent high capacity at the first machine may create a lower-quality output later.

This systems view is particularly relevant where recycled rubber is intended for further processing rather than sale as rough tyre-derived material. Reclaimed rubber and rubber compounds may require controlled particle size, stable contamination levels and consistent mixing behavior. In these applications, processing equipment such as an Banbury internal mixer can be part of the downstream process for rubber plasticizing or stock mixing. Its role is separate from tyre shredding, but the quality and consistency of recovered material strongly influence the stability of subsequent mixing.

Questions that reveal an unrealistic capacity claim

During technical discussions, several questions are worth asking directly:

• What tyre size range was used to establish the stated capacity?
• Does the figure include truck-tyre beads and steel belts, or were tyres pre-processed?
• What is the primary output size, and what screen size is assumed downstream?
• How does the control system respond to overload and cutter reversal?
• Which component is expected to be the capacity bottleneck for the proposed feed mix?
• What cutter inspection and replacement access is provided?

Clear answers do not need exaggerated performance claims. A competent supplier should be able to explain the operating assumptions, identify likely constraints and recommend whether a mixed-tyre line needs separate handling for oversized casings.

Equipment manufacturers with design, manufacturing, installation and commissioning capability can be helpful at this stage because the answer may involve layout changes rather than simply choosing a larger machine. JC INDUSTRY, which works across rubber and plastic machinery, environmental equipment and related mechanical systems, also operates a used machinery and equipment recycling center. For projects where capital allocation is tight, refurbished equipment can be worth evaluating alongside new equipment, provided the scope of refurbishment, critical wear components, controls and warranty terms are reviewed carefully.

The practical selection rule

Choose a tyre recycling machine around the largest tyre category that will be routinely processed, not the smallest tyre that dominates an early feed forecast. If oversized tyres are only occasional, a preparation route or separate handling procedure may be more economical than oversizing the entire line. If truck tyres are a regular part of supply, torque, feed opening, cutter design and steel-handling capacity should be specified accordingly from the beginning.

The most dependable throughput estimate comes from a defined tyre mix and a complete material-flow review. Without those two things, a single tonnes-per-hour figure is only a starting point—not a basis for investment.