The conversation in 2026 has moved away from pure brand vs brand comparisons, at least with regard to mining tires. Most of the downtime operators have experienced has been traced back to the way the tire has behaved under continuous load, heat build up in the tire, penetration of the sidewall, failure to soak up shock from an irregular terrain.

That is the reason why for 2026 and beyond, the OTR tire foam filling machine has become a class of equipment on its own, rather than a sideshow accessory maintenance machine.

For those using wheel loaders, articulated dump trucks, underground LHD machines, moving slag, containers, using telehandlers and military support vehicles, tire puncture has become from a simple repair issue to one of the continuation of productivity.

Manufacturers involved in integrated foam filled tire equipment projects today include Haifeng Automation, Haifeng PU Technology, Haifeng Engineering on interconnected projects involving:

• PU Production Turnkey Project
• Complete PU Manufacturing Plant
• One-stop Polyurethane Solution
• OTR Tire Foam Filling Machine
• Foam Filled Tire Equipment
• Eco-friendly PU Foaming Solution
• Polyurethane Equipment Operator Training
• PU Machine Remote Troubleshooting
• Retrofitting Old PU Machines
• Fully automated PU equipment solution provider

The reason is that today’s PU tire filling systems are often no longer simply “liquid injection pumps”. They are pressure-controlled PU processing systems with stringent requirements for:

• chemical metering stability,
• reaction temperature regulation,
• cavity pressure balancing,
• filling density reproducibility,
• and curing behavior under stress.

What an OTR Tire Foam Filling Machine Does

An OTR tire foam filling machine fills pneumatic tires with two-component polyurethane elastomer instead of compressed air, replacing it with fully cured microcellular polyurethane foam.

The finished tire is:

• puncture resistant,
• flat proof,
• load supporting,
• and resistant to catastrophic downtime.

The machine consists of:

• High-pressure metering unit
• A/B chemical storage tanks
• Heating and circulation module
• Dynamic mixing head
• Vacuum-assisted filling system
• Foam density metering controls
• Electrically confined explosion proof system
• Automatic tire rotation platform
• Remote diagnostic PLC system

For use in big-capacity mining facilities filling stations may include:

• robotically assisted hose positioning,
• automated tire barcode tracking,
• integration into curing room,
• linkage to MES production,
• and predictive maintenance linkups.

Why Did Foam Filling Become Increasingly More Important After 2023?

Between 2023 and 2026, mining fleets everywhere started to make changes toward:

• heavier equipment and trucks, including heavy electric equipment,
• and open use 24 hours a day.

That created a somewhat underestimated problem: pulling tires off the rim from static loading for prolonged periods of time, particularly when sidewall stressors put air-pressure tires at risk.

In the case of a normal puncture, it only stops one machine. When it is a truck on an Autobahn-style route for autonomous haulage, it stops a whole logistics system.

That sort of operational risk changed tires people were hauling to their job site.

These days quarry and mining operators choosing tire strategies on the job look at things like this for priority of consideration:

How the Polyurethane Filling Process Works

Step 1 — Tire Inspection Prior to Filling

Expert operators never start off with chemical preparation.

They begin with the carcass.

A tire casing with a sidewall separation lurking within might fail after being foam filled to perfection.

This step might be the most ignored by purchasers contemplating their first foam-filled tires.

In terms of performance post-foam filling, the foam-filled tire is only as good as the carcass underneath it.

What they need to look at:

• bead damage,
• cord exposure on the inside,
• sidewall fatigue,
• cracking from the heat,
• old patch repairs,
• and rim damage.

Step 2 — Vacuum Removal and Purging of Air

Before any injection of polyurethane, the air inside the carcass must be removed as far as possible.

Air left in the cavity manifests itself in:

• dyed in the wool of foam,
• localized heat,
• air pockets,
• irregular balance through the tire in the rotation of the tire.

The larger the tire, rim 25” and up, in a mining application, the more explosive the air pocket becomes to the new operator in use.

A small undercut catches air that may be forced up under heat of operation so that the foam itself pulls away from the tyre wall.

Step 3 – Reporting, Metering and Injecting Polyurethane

The machine reports, meters and injects polyol and isocyanate at the required ratio.

Typical filling systems aim for:

• 1 : 1 to 1 : 1·1 mixing ratios
• 80 – 140 bar injection pressure
• 35 – 55°C material temperature
• 0·35 – 0·9 g / cm³ foam density

More weight loading than this is dangerous and affects component life.

Density guided purchase by buyers of yore earlier in the process -for forks off lifts, a high density; medium high with underground mining loaders and rough-terrain agriculture machines; a medium density for port machinery; leaving for lightweight utility applications, a lapse to a less dense fill.

Paradoxically a better density does not always suffice.

Many a novice buying truck/scoot dudes think the routing through maximum density equals maximum durability – mistake!

a hard filled tyre tends to convey the shock down through axle bearings, suspension joints and hubs (shocks to uncle/ operator on badly graded mining roads btw) and ultimately wreck the general machine.

Experienced engineers on site then generally wangle the lowest density safely carrying loading.

I.e. “that” degree/ difference, rather than pure hardness, tolerable.

Why Mixing Head Stability is Important to Good Quality Foam Filling

The mixing head is, as far as there is in the foam filling machine, the heart of the complete filling process.

Slightest variation in the mixing pressure, away from optimum, invites improper polymerisation; an ‘eye’ with a weak core collapsing; foaming zones; contraction around its steel centre.

More sophisticated machines are seen incorporating a dynamic mixing head which ‘self-cleans’, and a servo-controlled metering and instantaneous adjustment viscosity.

“Such ‘requirements”, said ITT’s German associations, design is driven mainly by ‘among’ high-capacity OTR tire foam filling stations; explosion-proof tire filling machine solution environments from suppliers in the USA & Europe; and pneumatic systems used for tire flat proofing PU pump; tire switching replacing worn flat running continuous production. Vehicle minimizing downtime, and in the EU countries on putting PU to work”.

“Remote monitoring 2026 trend on advanced; China suppliers of PU machines for ‘export’ produced by China growing companies brings remote PLC diagnostics, and logging and alarming of pressures plus remote troubleshooting capability to reduce downtime in overseas factories where locally trained polyurethane engineers are scarce.

Applications Where Foam Filled Tires Excel

Mining and Quarry Operations

Whatever you call this business in your neck of the woods in the world, foam-filled tires do very well in exposure to:

• sharp rocks
• scrap metal
• debris from demolition
• tunnel work underground

Equipment in underground mines quickly recoups the price of filling if one tire outage is avoided.

Steel Mills and Slag Handling

The high temperature debris found in this environment equates to short-lived tires.

Foam-filled systems see less:

• puncture incidence
• sidewall spalling
• outage for urgent replacement

Port Logistics and Container Handling

Container yards will be focusing more on uptime predictability – which could be measured in terms of one disabled reach stacker messing up multiple loads.

Where Foam Filling Is Not Indicated

This is where our team of engineers step back from the sales brochure.

Foam-filled tires aren’t right for every application as any long-distance, high-speed movement will tend to:

• generate excess heat
• develop higher rolling resistance
• accelerate wear

They are usually not right for:

• highway use trucks
• high-speed subscription fleets
• family cars
• operations striving for fuel economy.

Another slightly less evident consideration comes around low temperatures.

While a properly formulated tire will be fine, some polyurethanes tend to stiffen significantly in extreme cold, changing the behavior of the ride and where the tire flexes.

Selection of the proper formulation is important in:

• Arctic mining
• operations at extreme altitude
• outdoor storage subject to freezing conditions seasons of reduced use.

Where the Technology Is Headed by 2026 for the OTR Tire Foam Filling Procedure

Smart Density Compensation

Machines will monitor tire cavities of shapes various, carcass loading physically, while also accounting for:

• heat to be generated while operating
• rate of speed
• crown shape to modulate density.

Lower Exotherm Formulations

In generating polyurethane foam a greater amount of heat was produced that got trapped, especially in larger tires.

New eco-friendly PU foaming methods stress:

• lower peaks of heat
• less change in size of foam through cooling
• a more stable curing process.

Bio-based Polyurethane Systems

Some operations are working with bio-based partially formulations for polyurethane to lessen their exposure to petrochemical sources.

This trend is seen in:

• solvent-free polyurethane manufacture,
• water based polyurethane systems,
• sustainable PU processing technology

Integrated Digital Service Systems

The biggest equipment suppliers now offer:

• polyurethane equipment operator training
• PU mixing head repair and maintenance
• remote commissioning
• predictive maintenance software
• retrofitting old PU machines

The equipment itself is no longer the whole business model.

Long term process stability support has come to be of equal importance to us.

Here’s how not to be conned when buying…

An OTR Tire Foam Filling Machine Vendor

Heaven help you if you are not serious.

Ask these technical questions to the machine maker:

1. What is the maximum stable tire size?

Look beyond nominal diameter claims.

Probe for bona-fide production logs.

2. What is stabilization of metering accuracy over continuous shifts?

Short test runs by themselves often do not uncover problems with thermal drift.

3. Will access be given for remote troubleshooting?

Very important if your overseas factories.

Very important for:

• integrated polyurethane machinery system for export
• turnkey polyurethane projects
• remote mining operation.

4. Is the entire electrical system explosion-proof?

Required for some industrial purposes.

5. When can mixing head be serviced without downtime part of the trouble?

Oftentimes, downtime arises more from inaccessibility of servicing than hardware failing.

6. May machine be integrated into more general PU production turnkey project?

Many buyers extend into latter years PU production line of PU safety shoes, and PU synthetic leather production line, and PU insulated panel continuous line, and complete PU manufacturing plant systems complete – here, integration capability is as significant as factor as many first-time investors realize.

Typical Filling and Curing Times for Large OTR Foams Filled Tires

Final results are greatly affected by:

• ambient temperature,
• chemical formulation,
• tire shape,
• and the knowledge of the operator.

The operator still matters a lot in 2026.

Even the best polyurethane foam filling machines let mix ratios get out of range if the sequencing isn’t correct.

That is why good suppliers are more bundling:

• polyurethane plant layout design,
• operator familiarization,
• commissioning assistance,
• and polyurethane input-to-output support.

Why Bundled Capability is More Important than Machine Cost

The hardware simply seldom represents the end result solely.

Too many failed frames were caused at the input by:

• bad workshop ventilation in some cases,
• incorrect chemical storage temperature in another,
• unstable compressed air ridges in some others,
• costly dead unfilled curing space in others,
• changing power grids in most.

Top engineering teams consequently evaluate:

• the plant layout,
• the chemical logistics,
• the operator workflow,
• the maintenance access,
• and the product throughput expansion opportunities as a single entity.

This is the impetus behind increasing demand from many for:

• polyurethane single source suppliers,
• polyurethane production line suppliers of China,
• PU machinery custom project turnkey capabilities.

The capital equipment marketplace is clear; away from machine and towards polyurethane fillables as an entire plant.

PREGUNTAS FRECUENTES

What Is an OTR Tire Foam Filling Machine?

An OTR tire foam filling machine injects a light-weight polymeric elastomer into a pneumatic tire to provide hollow, puncture-proof, flat proof tires for mining, quarrying, industrial and other heavy duty services.

What tires can be foam filled?

Tires used on:

• forklifts,
• underground mining,
• wheel loaders,
• skid steers,
• telehandlers,
• port equipment,
• military vehicles,

Among the fastest-growing filling categories for 2026 are large quarry and mining tires.

Are foam filled tires completely puncture proof?

No; foam filled tires will be less likely to experience a puncture and also less likely to be affected by air-loss failures since no compressed air is present in the tire to begin with.

However, the tire could still require replacement if the casing is badly damaged, if the bead breaks (on tire removal), or if the tire begins delaminating.

How long does it take to PU fill tires?

Filling time will vary depending on the size of the tire and the density of the foam.

Typical times are about:

• Forklift tires: 15-30 minutes
• Underground loader tires: 45-90 minutes
• Large tires for quarry service: 2-4 hours, plus an additional 12-72 hours curing time, varying with formulation of the material and ambient conditions.

How serious is the worst possible mistake in selecting the foam density?

Many first time buyers come with the notion that harder (higher density) foam is always a good thing and guarantees a longer life from the tire.

However, as every student of mechanics learns, too much density and therefore too little resiliency usually means more vibration transmitted to:

• wheel hubs,
• bearings,
• suspension system,
• machine frames,

so often operating on the principle of “just barely adequate,” the very astute engineer requests the softest density that will be at all suitable for his present, choice of work.

Are foam filled tires suitable for road use?

Generally not; foam filled tires are poor, indeed for:

• 97 any kind of,
• extended road use;
• high speed logistics of various kinds;
• desirably for passenger vehicle;
• less concerned for;
• cheap, transportation,

these uses may not be terribly suitable for high.

What is the difference between a high pressure and low pressure system?

In high pressure systems the mixing is more uniform, foam structure is uniform, filling speed is better, density is more consistent.

Low pressure systems are OK for small industrial tires; however; the small tires have sometimes been too small for the bigger OTR tires.

What is the mixing head and why is it important to foam filling equipment?

The mixing head is a fairly distinct part of the foam filling machine coming at a point where the various chemicals from the input lines come together and start, to mix and foam.

Where this “more” mixing strictly conforms to “better,” general principles of foam mixing, it leads to:

• a foam of denser structure,
• better,
• consistency start to finish;
• the time that the material foamed;
• to a maximum inward pressure of the foam;
• and so forth.

Poor mixing per se may instead, lead to voids mad in places inside the tire, foam, soft and spongy places, or loss of proper polymerization instead in this foam filling procedure.

What safety requirements does the modern OTR tire filling machine often have to provide?

Typically, many of the more modern systems may encompass:

• explosionproof electrical systems,
• automatic monitoring means;
• themselves able to shut down;
• safety;
• for excessive ambient temperature;
• remote trouble shooting;
• capability;

particularly for this hazardous industrial application.

Can antique PU foam filling machines be brought back to life?

Typically the manufacturer of such machines now will supply:

• retro known as;
• equipment for filling old PU machines with state of the art automation;
• high or represented use of computerized machine controls with new PLC’s.

Retrofitting older machines is oft claimed easier all right than touting all new machines with all those systems for some production, once of for all time, one.