A double shaft shredder for tires is the primary size-reduction machine at the heart of nearly every tire recycling plant. It uses two counter-rotating shafts fitted with intermeshing cutting discs to tear whole car, truck, and OTR tires into 50–150 mm rubber chips — the starting material for tire-derived fuel (TDF), rubber mulch, crumb rubber, and pyrolysis feedstock.
In this guide, we cover how a double shaft shredder processes tires, typical technical specifications, the complete tire recycling workflow, blade selection, and answers to the questions buyers ask before investing.
Why a Double Shaft Shredder for Tires?
Tires are one of the toughest waste streams to process. A typical passenger tire contains reinforced steel belts, bead wire, and textile cord embedded in a resilient rubber matrix — exactly the kind of contaminated, bulky material that defeats high-speed single-shaft machines.
A double shaft (twin-shaft) shredder solves this by operating at low speed (10–20 RPM) and high torque, using two counter-rotating shafts with interlocking cutter discs that grab, shear, and tear the tire apart rather than slicing it. This low-speed, high-torque action delivers several advantages for tire processing:
Handles whole tires without pre-cutting — car tires up to 800 mm and truck tires over 1200 mm can be fed directly.
Tolerates embedded steel — the shearing action opens the rubber matrix around steel belts rather than stalling on them.
Low noise and dust compared with high-speed granulators.
High throughput — from 1 ton/hour on small models up to 30 tons/hour on heavy industrial units.
Automatic reversal on overload— prevents jams when the rotors meet a thick bead or foreign object.
Technical Specifications
Specifications vary by manufacturer and model. The table below reflects typical ranges for double shaft shredders configured for tire recycling:
Specification | Typical Range |
Cutting chamber | 800 × 680 mm to 2400 ×1800 mm |
Rotor blade diameter | Ø300–800 mm |
Blade thickness | 25–100 mm (40–50 mm standard for tires) |
Blade material | 9CrSi, H13 / SKD11, Cr12MoV |
Main shaft speed | 10–20 RPM |
Motor power | 22 kW× 2 to 160 kW × 2 |
Input tire size | up to Ø2400 mm (OTR tires) |
Output chip size | 50–150 mm (primary), down to 20 mm (secondary) |
Throughput | 1–30 tons/hour |
Machine weight | 6.5–56 tons |
Note: Cutting chamber, rotor diameter, blade thickness, motor power, and output size can all be customized to your tire type and target capacity.
The Tire Recycling Process
A double shaft shredder for tires does not work alone — it is the first major stage in a multi-step liberation and separation line. Here is how the full process works:
1. Tire preparation and debeading
Whole tires are inspected, and for truck and OTR tires, the heavy bead wire is pulled out using a hydraulic debeader. Removing bead wire before shredding reduces blade wear and simplifies downstream steel recovery.
2. Primary shredding
The double shaft shredder reduces whole tires into coarse rubber chips of 50–150 mm. At this stage the steel belts and bead wire begin to detach from the rubber matrix. Some steel — particularly from sidewalls and beads — is liberated here and can be removed by an initial overband magnetic separator to protect downstream equipment.
3. Steel liberation and secondary shredding
A secondary shredder (sometimes a single-shaft shredder or a specialized fine double-shaft unit) reduces the chips to 20–50 mm, further exposing and freeing the embedded steel cord. This stage is critical for steel liberation — as rubber is cut away from the belts, the steel becomes magnetically recoverable.
4. Magnetic separation
Multi-stage magnetic separation removes the liberated steel:
Overband / crossbelt magnets capture large bead and sidewall wires after primary shredding.
Magnetic drum / head pulley separators remove finer wire after secondary shredding.
Rare-earth drum magnets capture microscopic steel fibers after fine grinding.
A well-designed line achieves over 99% steel recovery, yielding clean steel scrap for smelting and protecting granulators and grinders from metal damage.
5. Fiber removal and granulation
Air classifiers or zigzag separators remove textile fiber from the rubber stream. The clean rubber is then granulated or fine-ground to the target end product — crumb rubber (1–8 mm), rubber powder (down to 0.18 mm), or TDF chips (50–80 mm).
Output Products and Applications
The rubber chips produced by a double shaft shredder for tires feed several downstream markets:
Tire-derived fuel (TDF) — 50–80 mm wire-free chips burned as high-calorific alternative fuel in cement kilns, power plants, and pulp/paper mills.
Rubber mulch — 10–20 mm chips for landscaping, playground surfaces, and equestrian arenas.
Crumb rubber — 1–8 mm granules for molded products, speed bumps, and synthetic turf infill.
Rubber powder — fine powder for asphalt modification and new-tire manufacturing.
Pyrolysis feedstock — shredded tire chips processed into fuel oil, carbon black, and steel.
Recovered steel — clean scrap sold to steel recyclers and smelters.
Blade Selection for Tire Shredding
Blade choice determines output size, throughput, and service life. For tire applications:
Blade diameter: Ø400–500 mm is the common reference range for tires; larger OTR tire lines use Ø600–800 mm blades.
Blade thickness: 40–50 mm is standard for tires; 75 mm blades are used when processing heavy truck tires or tire/steel composites.
Blade material: H13 / SKD11 and Cr12MoV are preferred for tire recycling because of their hardness and resistance to the abrasion caused by steel cord. 9CrSi is a cost-effective option for lighter-duty car-tire shredding.
Hook configuration: Single-hook blades are the most versatile for tires; multi-hook blades improve grabbing efficiency on softer rubber.
Regular inspection every 200–300 operating hours and timely blade sharpening extend service life and maintain consistent chip size.
How to Choose a Double Shaft Shredder for Tires
Clarify these four factors before ordering:
Tire type and feed size — car tires (≤800 mm) need a different chamber than heavy truck or OTR tires (≥1200 mm).
Target hourly output — small batch operations (1–2 t/h) versus continuous automated lines (5–30 t/h).
Required output size — 50–80 mm TDF chips, 10–20 mm mulch, or finer crumb feed.
Steel content — whether you need an upfront debeader and multi-stage magnetic separation downstream.
Share your tire type, target capacity, and required output size, and we'll recommend the right model and blade configuration.
FAQ
Q:Can a double shaft shredder shred whole tires?
A:Yes. Double shaft shredders are designed to process whole car, truck, and OTR tires — up to Ø2400 mm on large models — without pre-cutting. For truck and OTR tires, removing the bead wire first (debeading) reduces blade wear.
Q:What output size does a double shaft shredder produce for tires?
A:Primary shredding produces 50–150 mm rubber chips. With a secondary shredder or granulator downstream, output can be reduced to 20 mm or finer, down to crumb rubber and powder.
Q:How many tons per hour can it process?
A:Throughput ranges from 1 ton/hour on small units to 30 tons/hour on large industrial models, depending on tire type, feed size, and motor power.
Q:How is the steel removed from shredded tires?
A:Multi-stage magnetic separation — overband magnets after primary shredding, magnetic drums after secondary shredding, and rare-earth magnets after fine grinding — removes liberated steel cord, achieving over 99% steel recovery.
Q:What blade material is best for tire shredding?
A:H13 / SKD11 and Cr12MoV are preferred for tire recycling due to their hardness and resistance to steel-cord abrasion. Blade thickness of 40–50 mm is standard; 75 mm is used for heavy truck and OTR tires.
Q:Can the machine be customized?
A:Yes. Rotor diameter, blade thickness, motor power, cutting chamber size, and PLC control systems can all be tailored to your tire type and throughput. Voltage and frequency (50/60 Hz) can be configured for any market.
Need a double shaft shredder sized to your tire recycling operation? Send us your tire type, target capacity, and required output size — we'll recommend the right model and blade configuration for your plant.
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