KUMHO TIRE Global Network
It is almost impossible to repair when damage occurs since a tire is made of series of finished products, not assembly of various parts. Only method to repair a tire is to fill up a gap when puncture occurs. But it is difficult to consider this method as perfect measure since it must be considered whether the puncture is repairable depending on damaged part and size and a tire once leaked is not perfectly performed even after filling up a gap.
A tire that performs rotation movement at a high speed with air full is easy to puncture due to nail or sharp stone. It is in distress if a new tire, tread wear is not so severe, becomes useless due to puncture. However, it must consider effect of tire puncture on safety before thinking it distressed. A tire once punched is excluded from object of maker's quality warranty. That a hole occurs so that air is leaked from a tire is witness that even steal belt in charge of steel strength as well as rubber surface is damaged. For a tire with critical flaw in durability, the quality warranty period is not applied and even speed degree is not admitted. Performance of a tire subject to critical damage due to puncture is speed. That is why tire maker or the repair shop recommends use the repaired tire only as spare. Repair of puncture must be considered as temporary means to “clog only wind hole” as the word means. It is specially prohibited to run a car with a tire whose puncture is repaired for a long time. It may result in rupture accident by giving unreasonable burden to the repaired part of a tire fragile to heat.
Damage of case, tread
A tread touching with the ground during run is a part fragile to puncture occurred. Mostly this puncture occurs when nail or sharp object penetrates into a thin groove between tread patterns. In this case, it is considered as repairable scope if diameter of a hole is usually within 5mm.If the hole is larger than this value, damage of the inner steel cord layer is severe and thus it must be considered as impossible to travel entirely after repair. If a fine wrinkle is formed so as to be difficult to discern with the eyes and thus air is once discharged, it is considered as puncture penetrated into the inside of the tire, and it is impossible to repair if the length is more than 5mm.
Damage of case, shoulder and side wall
Differently from tread where steel belt with high steel property is contained, the surface of tire composes of only a thin rubber and polyester cord. The polyester cord plays a role of supporting the shape of tire when air is injected info. If a hole generates at the side surface of tire made of a week structure, it is impossible to unconditionally repair regardless of the size of wound. That is why cord-cutting status expands to the neighboring part since supporting power becomes weak if polyester cord is broken in addition to weak rubber layer. Especially the shoulder part (jointing part between tread and side wall) that performs much extension and contraction is same as waist of the human body, and if it is damaged once, it cannot perform its own function at all.
Goods for repairing puncture of a tire largely include 2 types;
Patch Type, Sealant Type. For the sealant type commonly called as 'earthworm' , insert it into a hole part of tire using tools and fill the hole while pulling it again. Work is simple since immediate handling is possible without separating tire but a steel cord layer may be damaged in repair course. American laws regulate using of a sealant type of repairing product. For the patch type, attach thin film of rubber material to the hole-part. Spread and apply adhesive to the damaged part and firmly secure the patch. Though this method appears simple, more time and expense are required since work must be performed in the inside surface of tire after separating the tire from a car once.
Driver's method to manage and identify
There is no way for a driver to avoid puncture of a tire. However, to rapidly find and dispose puncture is very important to maintain performance of a tire. Tire puncture can be detected through driving sense. If a front wheel is punched, leaning of the car frame apparently appears and for a rear wheel, light shaking the ending part of a car is felt.If your driving sense is not so keen, it is good to check 4 wheels whenever you get on the car.If only wheel in either side apparently sinks down, it is certainly puncture. There is sometimes a driver who only fills tire inflation pressure when tire air is entirely exhausted.come. There is also method to find out the part where air drops come after submerging the whole tire in the water tank but this method is not frequently used due to burdensome work.If checking whether puncture occurs, replace with failed tire with a spare tire once and then move a car to the repair shop. If continuing to travel a car with a tire punched even though much air is not exhausted, performance of the tire may be aggravated such as occurrence of folding phenomena of sidewall.