Retreaded car tires, pros and cons. Starting a car tire retreading business How to make a tire retreading device

Today we will talk about how to independently restore the tread pattern of a car tire with our own hands. We will also consider technologies for the restoration of welding and cutting of tire treads with visual diagrams and photos

To understand where to go for tire retreading, you should first study the features of the services provided by various service companies. It is possible that this type of restoration cannot be applied to the wheels you are using or is associated with excessive risk. Consider ways to restore the tread.

Slicing This technique for extending the life of car tires is applicable exclusively to rubber for commercial vehicles. At the same time, not every truck tire can be cut - to make sure that your rubber is suitable for such a restoration, you should find the inscription "Regroovable" on it. Representatives of large vehicle fleets prefer to order tires directly from the manufacturer or an importer associated with it, so as not to encounter a fake that can become unusable when cutting. The essence of the technique is very simple - "Regroovable" tires have a fairly large protective layer of rubber located under the tread. Its chemical composition is completely identical to the top layer, so the new tread does not differ in characteristics from the previously used one. The specialist uses a thermal knife, heated to a high temperature and connected to a high-frequency oscillator.

The idea of \u200b\u200bretreading old rubber came to Russia from Europe. There, recovery technologies have been used for a long time, especially for trucks, 70% of which are driven by recycled rubber. The remanufactured tread does not differ from the original factory tread. The fact is that only the pattern wears out during operation, while the wheel frame is practically eternal, and it can be used several times.

In the United States, there is a practice of double retreading. While such a practice has appeared in Russia relatively recently, it has been used in Europe and the United States since the 90s.

Tire retreading methods

There are two methods of retreading an old tire - hot and cold welding.

Cold welding method. Cold retreading of tires can be carried out if the tire carcass is preserved. Before starting the retreading procedure, a specialist carefully examines the carcass. If there is no damage on it, then the master starts working.

The old protector will need to be removed, so it doesn't matter how much of it is preserved. Waste rubber is cut using a special machine. The remaining frame is repaired, if necessary, punctures and other minor defects are eliminated. The surface of the frame is sanded to create a rough texture. A layer of liquid rubber is applied to it, which will further ensure tight contact with the new tread. Natural rubber is used for the primer. After that, the master proceeds to restore the tread: for this, a tread tape is applied to the wheel. This is a kind of blank that will become the new protector. The tape is temporarily secured with staples.

When it cuts through the tire's protective layer, the rubber is immediately sealed to prevent accelerated wear. It takes about an hour to restore one truck tire using the cutting method, after which it must cool down the same amount before being installed on the vehicle. Hot vulcanization Even if there is no additional layer intended for cutting the tread, it is possible to build up the tread, or, as said earlier, "weld on". First, the tire is treated with an abrasive tool, producing the so-called roughing. Only 1.5 millimeters of rubber remains on the wheel over the cord - the minimum safe layer. After that, all the damages received by the tire during operation become visible - the consequences of impacts, cuts and other negative external influences.

They are treated with "plasters" made of raw rubber, after which the wheel is sent for vulcanization. The pre-treated wheel is subjected to quality control, after which a tie layer and new rubber with a pre-cut tread are applied to it. Now hot recovery begins - vulcanization at temperatures reaching 160-175 degrees. The procedure is quick and effective - the tire becomes very strong and durable. However, there are a number of disadvantages to hot recovery:

Increased wear of rubber during high temperature processing; Damage to the upper tread layer, which leads to a decrease in the permissible mileage; High probability of breaking the nylon or metal cord layer. Cold Vulcanization The disadvantages of the hot process have led many companies to find ways to reduce the temperature at which vulcanization is performed. Restoration is carried out in a similar way - during roughing, defects are found that are eliminated by gluing with raw rubber, and after preliminary vulcanization, a new tread is welded on top of the minimum layer.

The tire is transferred to the machine, where it is wrapped in an envelope with a tube and a rim and sent for vulcanization. This process is automated and takes place in an autoclave, thanks to which the structure becomes solid and monolithic. At the end of these works, the rim and the camera are removed.

After that, the tire is checked at the stand and installed on the car. Some car services give a guarantee for such a tire and assure that it will cover 40-60 thousand kilometers.

Hot welding. This retreading method uses the same raw rubber as new tires at the factory. The tire carcass is also cleaned of old tread and carefully checked for reusability. If there are no problems, the carcass is made smooth and prepared for retreading. To do this, using an extruder station, a strip of raw rubber is wound onto the frame. The tire is sent to a mold, where, under the influence of increased temperature and pressure, the tape is glued to the frame. New wheels are created in the same way. In the same chamber, the tread is formed and the rubber vulcanized. As a result, practically new rubber comes out of the chamber, which does not differ in properties from the factory one.

Pros and cons of different ways

These methods have advantages and disadvantages. So, the hot method makes it possible to carry out the procedure in a short time and get tires that are indistinguishable from factory tires, which pass as much as worn-out products. This method does not harm the environment and saves natural resources, but it requires bulky and expensive equipment, and auto repair shops rarely resort to hot welding of tires. This method is more often used by specialized enterprises.
Cold welding of tires is more widespread; it is used in car services. However, this method requires a lot of labor, takes more than one hour of time and can cost the car owner more than the method of hot welding. The resulting rubber is slightly inferior in quality to the new factory one and is capable of passing no less than a worn-out tire. In case of poor-quality welding, the layer with the protector often comes off.

Recovery efficiency

The main advantage of a welded tire is its reasonable price: it is often 30-60% lower than the cost of a new wheel, while the tread is higher than that of any used wheel. Buying such a tire is beneficial for the owners of trucks that move at low speeds. For cars, this option is not always suitable, since no one can give a final guarantee on how the tires will behave at an increased speed.

When purchasing a welded tire, it is required to proceed from the consideration that it does not last as long as a new one. The lifespan is 70% of the lifespan of a new tire. The fact is that the mass of a reconditioned wheel is higher than that of a new one, and this affects both the stability of the machine and the complete wear of the tread.

The condition of the donor rubber remains a mystery to the buyer, only if it was not your own retreaded tires. If you buy such a kit, then there is an option that the frames will be from different manufacturers, which shortens the life of the tires. To restore rubber, they use not such a high-quality composition as when created at the factory. Retreaded tires increase fuel consumption as the walls are wider than factory tires and the rubber itself has a pliable structure.

At the same time, a composition is used that the developers keep secret - it is a special material that allows recovery at relatively low temperatures. Cold repair works well for wheels that have previously undergone restoration - it is considered gentle due to the temperature of 100 degrees, which does not change the physical properties of the rubber. In addition, the cord retains maximum strength and elasticity, which allows it to maintain ideal parameters affecting handling and safety. However, not all tires may be suitable for cold vulcanization - this must be borne in mind when going to a specialized workshop. WHO IS THIS PROCEDURE FOR?

It should be understood that the listed recovery methods were originally developed for freight transport. If we talk about tread cutting in an additional layer of rubber, then this option is not available for cars - this is due to the small size of the wheels and high requirements for the comfort of the chassis. Therefore, car owners can only use vulcanization - cold and hot. However, in this case, there are limitations. Immediately, it is worth excluding the restoration of tires with low cord strength - that is, budget models of Russian, Chinese, Turkish and Korean manufacturers.

In addition, it is not necessary to restore the tires of high-speed models, since the behavior of a powerful car with such rubber will be simply unpredictable. There are only a few categories of middle-class tires left - and even after restoration they pass only 20-40% of the initial resource. It can be concluded that the restoration of passenger tires practically does not make sense. SAFETY Many drivers fear that after installing such rubber on their car, they will put their lives in danger, as the tire could explode at any time, leading to a serious accident. It is unfair to say so - statistics show that when restoring by vulcanization, the scrap rate reaches only 0.06%. In addition, the wheel will not burst even in this case, since the inside of the tire does not come into contact with the asphalt surface. The most likely damage is peeling of the top layer of rubber, which does not lead to dangerous consequences.

Tire retreading - a necessity or an opportunity for some cost savings? What is a Protector? How to cut it? Which tool to use - homemade or professional? Is it better to do everything yourself or go to a specialist? Such doubts and questions torment a lot of motorists whose tires are worn out or the time has come for their replacement. First, you need to decide what a protector is, and only after that prepare for its resuscitation.

A tread is a part of a tire designed to purposefully increase the tire-to-road contact patch.

In addition, it protects the inner part of the "rubber" from various damages (tears, punctures and breakdowns, side cuts, etc.).

Almost all tires can be divided into 4 categories by tread type:
Slick and half slick. In this case, the protector is almost absent. Used exclusively in racing, normally not used due to aquaplaning.

Summer and all-season tires. This type does not have a mass of cuts and notches on the sides, and the depth of the pattern is relatively small.

Winter tires (including studded ones). The tread of such rubber is deep, and is also distinguished by the presence of a large number of sipes (notches and cuts).

Off-road rubber and low pressure tires. It is characterized by large checkers of the pattern, allowing to ensure adhesion to any surface, as well as quick cleaning of dirt.

In addition, the protector can be:
directed;
undirected;
symmetrical;
asymmetrical.

CUTTING THE TIRE TREAD WITH YOUR HANDS

There is no strict need for this procedure - if you have an outdated tire, it is easier to throw it away and buy a new or used tire of good quality. But there are situations when the car owner assesses the condition of the tires before installing and comes to the conclusion that they will almost be enough for one more season. In this case, there is a reason in the groove of the tread, which will help the rubber "hold out" to the last line.

Can tires be cut? There are a lot of diametrically opposed opinions on this score. Some argue that this can and should be done, justifying such actions with those dividends that the owner of the car will save. Others warn against this practice, pointing out that during this procedure, almost 100% of the cord will be damaged, and the rubber is irretrievably damaged.

In fact, you can cut rubber, but only those products that are marked with one of the following markings:
"Regroovable";

Such a mark means that the manufacturer allows cutting the tread on this tire. In this case, during production at the enterprise, a special layer of rubber is deliberately created, which allows these manipulations with it, without fear that the strength characteristics will be reduced, and the integrity of the product is violated.

The problem of disagreement lies in the fact that many popular "kulibins" do not pay attention to such markings and cut the tread on all tires in a row. Naturally, at high speed the consequences will be disastrous, so it is not recommended to rely on chance.

Which tool to buy?

There are many options for building a homemade cutter, but experts recommend abandoning such an idea and using only certified products.

For work, you must use only professional tools and rubber suitable for cutting!

Tread cutting machines can be different - from the simplest ones, which do not have protection against overheating and with a limited number of cutting blades, to "advanced" ones, which have power control, protection of equipment from overheating, trapezoidal and rounded blades and other "devices".

The simplest models can be purchased for up to 8,000 rubles. For example, the German device S125B, which costs 7,800 rubles. It is used only for working with passenger car tires and has all the above disadvantages and limitations.

As for the top versions, the German S146B device remains very popular, selling for 17,500 rubles. Such a tool has a special thermal sensor and a housing equipped with a toroidal transformer. All this increases labor productivity. The transformer is made in a cast version, with moisture-proof insulation. The device is equipped with a convenient holder and a flexible power cable, which greatly simplifies operation. There is a switch (high-temperature type) and an additional possibility of adjusting the knife settings, and it is fully compatible with the RILLCUT type knives (already available). This device is designed to cut grooves from 2 to 12 mm in depth and 2 to 20 mm in width.

Process technology

Before starting work, you need to stock up on a professional tool, and then carefully clean the tire and inspect it for defects or damage. If there are any, they need to be removed (if possible) and only after restoration to start work.
Make sure that the given tire is suitable for tread cutting - there should be an inscription “Regroovable” on the side. If it is absent, the tread deepening is unacceptable. It is also worth paying attention to the slicing indicators that are available on many tires. They will help to clearly determine the need for the procedure.

Measure the tread depth, but this is done exclusively at the most worn out point. In case of uneven wear, it is necessary to work so that the thickness under the tread is at least 3 mm.

Dismantle the tire and inspect its inner surface - the sealing layer (inner) must not be damaged. You also need to shake out all the stones from the tread, as well as implement the repair of sipes and grooves, if any.

Install the cutter. As a rule, this value is equal to 3-4 mm. However, there are other indicators.

Start slicing directly. It is necessary to work at a good pace, because the presence of burning and the smell of burnt rubber indicates either a too high power parameter, or insufficient work speed. Cutting should be done in small strips - up to 15 cm, and the cut material must be removed immediately.

At the end of the work, it is recommended to clean the grooves from the stuck rubber pieces, after which you can install these wheels on the car. They can be installed on both the front and rear axles. But it is preferable all the same on the back, or generally on the trailer.

Tire retreading methods

There are two methods of retreading an old tire - hot and cold welding.

Cold welding method... Cold retreading of tires can be carried out if the tire carcass is preserved. Before starting the retreading procedure, a specialist carefully examines the carcass. If there is no damage on it, then the master starts working.

After that, the tire is checked at the stand and installed on the car. Some car services give a guarantee for such a tire and assure that it will cover 40-60 thousand kilometers.

Hot welding. This retreading method uses the same raw rubber as new tires at the factory. The tire carcass is also cleaned of old tread and carefully checked for reusability. If there are no problems, the carcass is made smooth and prepared for retreading. To do this, using an extruder station, a strip of raw rubber is wound onto the frame. The tire is sent to a mold, where, under the influence of increased temperature and pressure, the tape is glued to the frame. New wheels are created in the same way. In the same chamber, the tread is formed and the rubber vulcanized. As a result, practically new rubber comes out of the chamber, which does not differ in properties from the factory one.

Pros and cons of different ways

These methods have advantages and disadvantages. So, the hot method makes it possible to carry out the procedure in a short time and get tires that are indistinguishable from factory tires, which pass as much as worn-out products. This method does not harm the environment and saves natural resources, but it requires bulky and expensive equipment, and auto repair shops rarely resort to hot welding of tires. This method is more often used by specialized enterprises.
Cold welding of tires is more common; it is used in car services. However, this method requires a lot of labor, takes more than one hour of time and can cost the car owner more than the method of hot welding. The resulting rubber is slightly inferior in quality to the new factory one and is capable of passing no less than a worn-out tire. In case of poor-quality welding, the layer with the protector often comes off.

Recovery efficiency

DIY tire tread cutting

Watch the pros make a regrover and cut their own tires

Outcome

A retreaded tire has a reduced load and speed index, therefore, these tires must be used with caution for passenger cars. However, for trucks and commercial vehicles, such rubber is an ideal option, since the car does not need to move at an increased speed, and reconditioned tires are much cheaper than new ones.

So if you prefer fast and agile driving, it is better to refrain from using retreaded tires and buy tires with reliable tread.

From my own experience I know that not all rubber products can be restored, i.e. give them their former elasticity and softness, after it has become callous. In general, a small part of rubber can be brought back to life if we are talking specifically about rubber, and not about the latest polymers, which do not lose their physical properties at a certain operating temperature.

The only difference is that rubber products, namely the material "rubber" itself, undergo a process such as vulcanization in the process of their manufacture, when the base of the rubber - the rubber - turns into rubber when interacting with certain substances at a certain temperature. Rubber was a new material in which rubber molecules created a single spatial network, it is due to this single mesh that rubber has its own physical properties.

It will not be practical to talk about all rubber products in one recommendation, since there are a lot of types of rubber and each rubber has its own intrinsic properties, as well as the degree of rubber saturation, the ability to crystallize and orientation, the strength of the chemical bond chain and the flexibility of macromolecules.

There are 5 main factors that affect aging and loss of elasticity:

light exposure, in which an irreversible process of photo-oxidation of rubber occurs.
ozone exposure, which results in cracking of stressed rubber.
thermal effect destroys the spatial grid.
radiation exposure destroys the bond of molecules.
vacuum action tears apart individual areas in the product.

All this negative influence leads to the fact that the rubber becomes hard and / or brittle. If the product crumbles, then it will not work to give it elasticity, since the bond between the molecules is broken.

But if the rubber has become hardened, but has not begun to deteriorate, then it can be brought back to life.

One of the misconceptions is that many advise to dip or spray on the product with solvents, gasoline or alcohol. This cannot be done, because, firstly, there is oil-petrol resistant rubber, which simply will not accept these liquids, and secondly, other rubber products simply dissolve partially or completely in these solvents, and the elasticity effect will only be temporary.

But one of the actually effective solutions that can "revive" rubber products is ammonia solution with 5% concentration.

In this solution, the product should be held for no more than 15 minutes, then, if possible, knead it by mechanical pressure and process it with the following composition.

After softening, place the product in water-glycerin solution with 5% concentration.

The product must also be held in this solution for no more than 15 minutes.

The temperature of the solutions should be within 40-50 degrees.

There should not be a long time between the two solutions, since ammonia destroys rubber with prolonged exposure, and glycerin on water slows down this process.

Ammonia solution 5% is not on sale, for this reason you will have to buy 10% and dilute it with distilled water according to the formula (see the chemical formulas, I personally can make a mistake)

5% water-glycerin solution is also not on sale, there is only pure glycerin or 85%, it must also be diluted to obtain the appropriate concentration.

In most of the most developed countries, such companies exist and successfully flourish that provide a range of services for the restoration of worn-out automobile rubber. Even world-renowned high-quality tire manufacturers also have subsidiaries dedicated to the respectable retread of worn tires. Thus, tires that have been remanufactured are returning to store shelves and are very worthy options for thrifty drivers, tempting them with their democratic cost, which is very different from the price of similar car tires. But the next question involuntarily arises - is it safe to "shoe" your car in such tires?

Basic recovery methods

Recently, the governments of the countries have been trying to optimize waste from automobile production as much as possible, therefore, recyclable materials are utilized as much as possible to further save financial resources and environmental protection. The new life of tires that have worked out their potential saves half of the total costs, and this, you see, is a significant amount. Car tires are rebuilt in two main ways:

Increasing the tread grooves with further creation of its pattern.

Hot and cold retreading by adding new tread.

In the first method, the used tire is thoroughly cleaned and, according to the original tread pattern, it deepens further into the rubber layer, which naturally leads to its reduction. This method can not always be called safe, because the behavior of such tires on the roadway is simply unpredictable. The second method provides two ways to develop further tire recovery:

Cold build-up consists of gluing a new layer of rubber ring over the existing tread.

Hot build-up involves applying an additional rubber layer using vulcanization.

Repaired tires serve almost identically, but with the first method, you can reanimate the tire several times, but the second is less prone to marriage.

Cold build-up

Unfortunately, not all tires can be restored. Here you need to take into account the state of their frames. Therefore, the tires are initially diagnosed, during which all damage received during operation is analyzed. The inner and side sides of the tire, its beads and crowns should be as intact as possible, since this is the key to further exploitation.

In the second step, it is removed. The tire is placed in a special apparatus, where it is inflated with air, and the upper rubber layer is removed from it. The third stage is called roughing. On it, you can determine which wheels are badly worn out, and weed them out. Reanimation tires eliminate minor flaws, such as cuts and punctures.

Rebuilding a rubber tread requires certain skills. The new expandable rubber ring is covered with liquid rubber, which allows you to reliably and efficiently remove old damage, ensuring a tight contact of the tread with the carcass.The wheel is primed with a hand extruder, then a tread with a certain pattern is applied. The rubber layer is trimmed around the circumference of the wheel on a fully inflated tire.

On special equipment, the tire is folded like an envelope and put on the rim and tube. Further, the restored tire is subject to vulcanization in an automated autoclave, where the tread ring is securely attached, merging with the frame together. The rim and tube are then removed. Further, the reconditioned tire is re-diagnosed and equipped with a warranty card. Some car services provide a guarantee for 100,000 km.

Hot way

This method is similar to the previous one in several points:

1. Primary diagnostics.

2. Sherokhovka.

3. Basic renovation.

4. Applying a new layer of rubber.

But, despite this, these processes for restoring car tires vary significantly. Using the previous method, it is possible to reanimate large-diameter car tires: tires of SUVs, trucks and large equipment.

The hot method is carried out as follows:a simple rubber layer that resists vulcanization is applied to the worn tire. Further, the protector is applied at the time of vulcanization.The new tread pattern is applied to molds that work under high pressure and at temperatures of 140 ° C. Nowadays, this method is used very rarely, but it is optimal for cars and minibuses with tires R13 – R16.

How to identify a remanufactured tire

If you are faced with high-quality tires, then on the sidewall of the restored rubber you will see a special marker, which indicates that the wheel has been given a second life. Typically, it looks like Retread, Remould, or Regummerat, depending on which version is English, American or German. If the restoration took place in Ukraine, then it will be possible to see the familiar word - "Renovated".

You can also find other distinctive properties of tires that were subject to restoration. So, for example, a special mesh of microcracks on the tire sidewall, which has not been touched by the recovery process. Rubber lumps on the inside that indicate repair or repair of a puncture. Be that as it may, a retreaded tire can be distinguished from a new one, the main thing is only to carefully examine the goods.

Pros and cons of purchasing

If you are faced with the choice of purchasing new or remanufactured tires, you should be aware of all the risks that previously used car tires are exposed to. As you already know, there are several ways to repair car tires. A lot of money is spent on such a procedure, since specialized equipment, trained personnel and high-quality restoration materials, preferably of Ukrainian production, are needed. It is not at all a secret that many motorists are more focused on products that are imported from abroad. After all, a worn out tire, repaired with our materials, acquires a controversial quality and reliability. But using foreign consumables is quite expensive.

It is allowed to restore passenger tires only with slight wear, but practice shows that this is simply impossible, and only a few with good external data can be restored. It is not always possible to balance a wheel with a reconditioned tire, and this is a significant drawback.

So, if this technology has so many negative sides, then why is it used? In fact, everything is not as sad as it might seem at first glance. A car with high mileage, knurled over a short period of time, will be great to drive on reanimated tires. Smart craftsmen are able to quickly, efficiently and reliably restore such tires with the appropriate equipment. Remanufactured winter tires can save you a lot of money. Experts can do the following:

1. Repair the cord with new threads.

2. Eliminate microcracks using thermal sealing.

3. The most worn-out areas will be built up using rental or ultrasonic examinations.

4. The new layer will be glued to the tire so that the tire looks like new.

When changing tires, car owners often encounter tire deformation. Cracked rubber is a good reason to think about replacing or restoring it. The entire radius of the wheel is sometimes covered with small cracks, but it is still possible to move around the city on it, especially if the tires are tubeless, but driving outside the city limits is not recommended. Large cracks with delamination extending from the cord itself require special care. And if such a phenomenon as bedsores with what to treat should be determined by a medical specialist, then "treatment" of car tires from cracks is the business of automobile "doctors".

Features of the rubber recovery process

It is worth taking medical and preventive measures for the rubber of your car in a specialized center. The way to restore rubber is to melt or weld it. But here you need to consider two points that any motorist should know. Firstly, it is necessary to take into account the wear of the rubber, because restoration - no matter how much we want it, the pleasure is not cheap and sometimes it simply does not justify itself. Secondly, when it comes to tires and, moreover, brakes, savings are excluded.

the use of low-quality raw materials for the production of tires;
tire mileage;
storage of rubber outside of compliance with the established rules;
more rarely, incorrect "overfitting" of rubber.

In addition to rubber on the wheels, rubber elements of the body kit and the seals of the trunk and doors can also crack. And if the most effective remedy for pressure ulcers, for example, "Proteox-TM" is a thin wound covering with the main components intended for the treatment of various pressure ulcers, including those infected. That professional means for the care of rubber elements can be at least "Gummi - Pflege Stift", developed by Sonax and outwardly resembling a pencil marker. The product is focused on restoring the elasticity of rubber, cleaning its surfaces from dirt and imparting a characteristic shine. The tip of the pencil moves, actively introducing into the surface of the rubber coating, the so-called silicone component, which forms a stable film that prevents cracking and aging of the rubber. Carry out maintenance on your tires, have a marker pencil in your glove compartment and may your road be successful!