What is the principle of tire repair fluid?

[AdrianRose]

Tire repair fluid is a white foam-like liquid, which is a high molecular compound compressed in large quantities in a canister. It can be injected into the tire through the valve stem to inflate the tire. When the tire repair fluid is injected, the centrifugal force generated during the car's movement can spread it over the inner side of the tire, forming a sealing film that serves the purpose of repairing the tire. The method of using car tire repair fluid is as follows: 1. Shake the tire repair fluid well and lift the outer tube; 2. Align the tube opening with the tire valve and tighten it; 3. Tear off the fixing ring on the top of the bottle and open the switch; 4. You can see the white liquid being injected into the tire through the tube. After inflation, turn the valve counterclockwise to close it.

[SanArthur]

Tire sealant works by using particles and viscous components in the liquid to plug leaks. You attach the can to the valve stem and squeeze it in, and the tiny fibers and rubber particles inside will spread throughout the tire as it rotates. Once they encounter a puncture, the air pressure pushes them into the hole, where they get stuck like a clog in a pipe. The glue-like substance inside also forms a sealing layer while releasing compressed gas to inflate the tire. I used it once when my tire got a nail puncture—it can indeed serve as an emergency fix for a few dozen kilometers, but it’s only suitable for holes smaller than 6 mm. Sidewall punctures won’t work. After use, a layer of residue remains inside the tire, so you’ll need to visit a repair shop for a thorough cleaning before getting a proper patch repair.

[JasmineRose]

The working principle of tire sealant is quite interesting. When you inject the liquid into a flat tire, the suspended particles inside are evenly distributed by centrifugal force as the wheel rotates. When encountering small holes caused by nails, these particles are sucked by the pressure difference to block the gap. The polymer material in it hardens upon contact with air, forming a physical seal. I've seen repair technicians demonstrate it—the puncture stops leaking within minutes. But don't expect it to be a permanent fix; this stuff can corrode the wheel hub coating and cause tire imbalance—you'll feel the steering wheel shake at speeds over 80 km/h.

[OJoanna]

Tire sealant is essentially a flowable sealant. The can contains a latex solution mixed with fine fibers and pressurized liquefied gas. When injected into the tire, these components flow toward the leak point as the tire rotates. The fibers interweave into a mesh at the puncture, while the adhesive fills the gaps to form a sealing layer. I once repaired a 3mm nail hole, and it stopped the leak in just three minutes. However, it's completely ineffective for sidewall damage and can clog tire pressure sensors. The key point is that after temporary emergency use, the tire's inner wall must be cleaned; otherwise, residues can accelerate rubber aging.