Retreading

Retread Technology

Retreading involves removing used tire treads and applying freshly vulcanized new treads so that the body of the tire can be reused safely.

Retreading not only helps to reduce the total cost of tires, but also makes a major environmental contribution in terms of the more effective utilization of natural resources.

Technology and Retreading of Tyres

Technology and Retreading of Tyres
 

Contrary to popular opinion technology is very important in retreading of tyres. Vehicles are in contact with the road through the tyres and the quality of tyres and retreads determines to a large extent road safety.

Today the technology available with Tyresoles is comparable with retreading technology in United States and Europe. It is important to select the correct rubber formulation for different applications and Tyresoles has access to rubber formulations for all types of applications.

Many smaller retreaders use hand buffers and builders to process tyres. This creates distortions in the tyres and misalignment on the vehicle, causing substantial damage to the vehicle. At Tyresoles, tyres are buffed, built and cured in inflated conditions.

In the United States, the largest retreading chains are run by Michelin, Goodyear and Bridgestone and retreading is an integral part of the tyre business.

Challenges in Retreading Tyres for Earthmoving Equipment

Heavy earth moving equipment like dumpers carry loads varying from 40 tons to 180 tons and tyre sizes vary from six feet to 12 feet. These are expensive pieces of equipment with the tyre cost ranging from Rs 1 lakh to Rs 15 lakh per tyre. Tyres for such equipment are known as Off-The-Road tyres or OTR tyres and have very special requirements for retreading.

Tyresoles repairs and retreads bias ply and radial OTR tyres using special moulds, with each mould designed to match the tyre size. Often different manufacturers of tyres do have slightly different sizes. And the retreader needs to have appropriate equipment to process all these tyres.

Most retreaders in India do not have the retreading machinery to retread radial tyres. Radial tyres present a significant challenge for repairs and retreading since radial casings do not expand or contract like bias ply tyres and placing radial tyres in bias ply moulds will damage the tyres.

Tyresoles: The Company

Tyresoles is the leading tyre retreading company in India. And has more than 6 decades of experience in the field of retreading. Tyresoles started as a unit of Anglo-Thai Corporation and was acquired by the Sah & Sanghi in 1973. The Belgaum factory was established in 1984. The company has seen year-on-year sales growth of 30% for the last two years and is projecting sales growth of 50% for the next year.

India's single largest
speciality Retreading & Repairing Facility

Tyresoles (India) Private Limited, India’s largest retreader, with state-of-the-art facilities to retread tyres has doubled its production capacity for all the sizes of tyres at its factory at Belgaum.

In 2010 the company consolidated its production facilities in Belgaum on a 4 acre plot with three state-of-the-art plants, dedicated to truck, tractor and earthmover tyres, bringing the total installed capacity to 250,000 tyres per annum.
Tyresoles has also expanded its distribution network to Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh and Himachal Pradesh. The ERP run company has grown significantly over the last few years and plans to expand to other states this year.

Widest Range, Widest Applications

Tyresoles has always focused on customers, developing products and processes to meet newer and newer requirements. It is the only retreading company in India to retread tyres from auto rickshaw sizes to 125 ton dumper tyres. Tyresoles retreads both bias ply and radial tyres in the conventional mould cure and the precured process.


Retreading Radials

Tyresoles has also introduced the state-of-the-art Rema Tip Top system to repair truck and bus radial tyres. Tyres that would need to be scrapped in the past can now be put back in service in tubeless conditions.
The new Earthmover retreading factory covers 14,000 sq ft and can retread 500 tyres per month. This new factory has sophisticated material handling equipment to move tyres easily. Equipped with a Rema Tip Top Thermo press, this facility can repair cuts upto 12 inches in diameter.

Tyresoles is also the only retreader in India to retread radial tyres in 6 segmented moulds.


Advantages of Retreading

Tyre retreading saves you money. Today, tyre retreading costs are about 25-30 percent of the cost of a new tyre. The life of the retreaded tyre is approximately 60-80 percent of the life of a new tyre. In terms of running kilometre retreaded tyres therefore cost about 30 percent of the cost of a new tyre resulting in substantial savings.
Tyre retreading is also essentially a recycling process. In Western countries, tyres cannot be put in landfills and must be recycled.
The government also offers incentives to recyclers to recycle worn out tyres. 

 Retreading Process

Initial Inspection

 

Each tyre received in a retread plant is subjected to a rigorous visual inspection. Inspectors are assisted by the use of non-destructive sophisticated inspection equipment.

We also purchase a new machine (Inspection Spreader).This Inspection Spreader designed to detect pinholes, nail holes, cuts, cracks, porosity,etc,Automatic tyre rotation stop when penetration detected with sparks.

Buffing

 

The tyre’s old tread is mechanically removed on high speed buffers. Today’s buffers are extremely accurate and will remove the proper amount of old rubber while turning the tyre to an exact specified diameter and radius.

Skiving & Repairing

 

With advances in state-of-the-art repair materials and repair methods, many of these tyres can be routinely repaired and in most cases can be retreaded when the original tread is worn off. The repair station is where any surface injury is treated using effective material and tools for grinding and patching.

Cementing & Filling

 

Even in small injuries it is critical that the injury is cleaned and filled. If this is not done, severe rust, separation and steel cable looseness could take tyre out of service. The injury should be inspected, and then cleaned out with a carbide cutter. After cementing the injury, a vulcanizing rubber stem should be applied to “fill” the injury. This would create a permanent repair that maximizes tyre life.

Building

 

In the pre-cure system, the tread rubber has already been vulcanized with the new tread pattern design. The buffed tyre needs a thin layer of cushion gum to be wrapped around its crown area. The pre-cured tread rubber is then applied with the building machine. This is called the building process.

Enveloping, Rim Mounting & Double Envelope System

  

a) The built tyres are then mounted with envelops and rims to prepare them for curing.

b) For enveloping, tyres are first fitted an outer envelope at the envelope-mounting table before the inner envelope is fitted into them. The enveloped tyres are then vacuumed out for preparation prior to curing. Modern plants have their casings hoisted by monorail systems.

Curing by Chamber (Precure)

 

The Precure Tread system is a process by which a tread pattern is fully cured or vulcanized into the tread by using a press. The tread is then vulcanized onto a tire casing using a bonding layer of uncured natural rubber. The tyre is vulcanized with heat, time and pressure in a curing chamber that bonds the tread to the casing. This thin layer called precure cushion or bonding gum. Cold retreading was then a term used to describe a process in which the final curing of retread is done at temperature lower than 115c.

Hot Process (Hotcure)

This system is similar to the technology of new tyre manufacturing.

Hot retreading is the term used to describe the retreading process in which the curing of retread is done at a temperature of above 140c. It employs a steel or aluminum mold with a tread design cast or machined into it.

Final Inspection (Presure Test) & Painting

• Tyre inflation pre-set at 2, 4 & 8 bar (max) for a better QC inspection.
• Enclosed by steel cage as safety protection.
• Testing cycle ended automatically to reduce supervision work.
• Well lighted within the cage for better visual inspection.

The retreaded tyre is subjected to a final inspection. This inspection insures that only tyres that meet industry quality standards are allowed to leave the retread plant.
All retreaded tyres are encouraged to be returned with the sidewalls painted using a light coat of black tyre paint.