Self-Healing Tyres

Core Working Principles and Technical Characteristics

Automotive self-healing tyres are a specialised safety tyre technology engineered to automatically seal tread punctures caused by sharp objects (such as nails and screws) and maintain air pressure without requiring manual intervention. Their core working principles primarily rely on two modern material science approaches: 

Polymer memory sealant technology: A layer of highly viscoelastic, semi-fluid sealant (such as polyurethane or butyl rubber-based compounds) is pre-coated beneath the tyre crown's inner liner. When an object penetrates the tread, the internal air pressure forces this polymer layer to instantly envelop and seal the puncture; once the object is removed, the memory sealant layer instantly rebounds to fully plug the hole, preventing air loss.

Self-vulcanisation / microencapsulation technology: Special catalysts or microencapsulated healing agents are blended directly into the rubber compound. When localised tread damage occurs, the resulting frictional heat or exposure to air triggers a chemical cross-linking reaction, prompting the rubber molecules to bond, cure, and seal cracks automatically.

In terms of performance characteristics, self-healing tyres effectively mitigate the risk of sudden pressure drops or blowouts caused by small punctures (typically under 5 mm in diameter, such as small nails or glass shards), all without compromising everyday ride comfort or rolling resistance.

Global Market Applications and Evolution

As a key premium tyre technology that elevates all-weather driving safety for new energy vehicles (NEVs) and eliminates the hassle of roadside spare tyre changes, self-healing tyres have been widely adopted by major global tyre manufacturers and selected as original equipment (OE) for mid-to-high-end passenger cars.

In terms of technological evolution, self-healing tyres are rapidly advancing towards lightweight polymer composite coatings, enhanced sealant stability under extreme weather conditions (from freezing temperatures to scorching heat), and deep integration with dedicated EV formulations tailored for low rolling resistance and extended range. Modern self-healing tyres have evolved from early aftermarket spray-on solutions into factory-integrated, high-end active and passive safety features.

Operational Guidelines and Safety Limitations

Although self-healing tyres can automatically seal minor punctures, the technology is ineffective against larger punctures (typically exceeding 6 mm in diameter), sidewall cuts, torn tyre cords, or severe tyre bulges. Drivers must still visit a professional tyre workshop for inspection once a foreign object is detected; continuing to drive at high speeds with severe structural damage is strictly prohibited.

When carrying out professional tyre repairs or tyre mounting and demounting, technicians must use dedicated cleaning solvents to completely clear the polymer sealant layer around the puncture site, strictly following standard internal or external cold or hot patch procedures. Applying a patch over an uncleaned sealant layer will prevent it from bonding securely to the inner liner, creating a potential hazard of secondary slow leaks.