Tyre Retreading
Renewing the tread for a structurally sound tyre casing
- What is tyre Retreading / Recapping?
- Tyre Retreading Process
When tyres become worn, they can be restored with new tread. From reputable research sources, there is no significant difference in quality between new and retreaded/recapped tyres. Many tyres can be repeatedly retreaded, delaying the landfill disposal of the tyres and enhancing our environment through recycling. Large truck tyres are typically recapped as part of a routine tyre – management program. Two reasons are cited for this preference. First, the low cost to retread tyres makes it a cost-effective routine measure for modern tyre-management program. Second, precure retread tyres are perceived to have higher mileage return than new tyres.
Tyre Retreading is the process of renewing the tread for a structurally sound tyre casing. The remodeled casing is then put through a curing process that causes the new rubber to vulcanize to the new casing. The new result is a new tyre with a fresh tread pattern. The retread process:-
1. Collection of Casings
Worn tyres are collected to select suitable casings for tyre retread.
2. 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.
3. Buffing After inspection
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.
4. Section Repairs & Skiving
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.
5. Cementing and 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.
6. Building – Tread Rubber
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.
7.
a) Enveloping & Rim Mounting or
The built tyres are then mounted with envelops and rims to prepare them for curing.
b) Double Envelope System
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.
8. Curing by Chamber
The tyre is then placed in a curing chamber and the pre-cured tread becomes adhered to the tyre through a vulcanizing process.
9. Final Inspection & Painting
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
Our Retreading Process
1| Inspection Station
Auto Aid retread technicians are known for their intense analysis. We inspect every retread casing manually from bead to bead with diligence and precision. Each casing also undergoes electronic nail hole detection to ensure no damage is overlooked. If a repair is needed, that casing is sent to the Repair Station.
2| Buffing Station
Purposely to create top-quality tread-building through proper texturing and uniformity, ensuring the tread bonds with the casing for superior strength and long tread life. This is what our customers have come to expect. Done by inflating the casing to its operational shape and then “buffing” out the worn tread thoroughly with computer-aided precision.
3| Repair Station
Casings in need of repair are sent to the Repair Station, where they are repaired thoroughly and efficiently from crown to interior by our technicians, setting up the casing in a top-quality operational state for the Tread Building Station.
5| Tread Building Station
Precured tread is now applied to the casing. The tread building machine utilizes exact casing measurements to ensure precise tread application. After the tread is applied, the tire moves to the enveloping and curing step.
6| Enveloping & Curing
Before a tire is cured, it first receives a curing envelope to ensure temperature and pressure uniformity in the curing chamber. The tire is then cured in a customized curing chamber to set specifications of time, temperature and pressure, depending upon the tread selected. The result is industry-leading retread uniformity.
7| Final Inspection
All Auto Aid Limited® retread starts with a thorough inspection and ends with a thorough inspection. No tire leaves the factory without undergoing a detailed, hands-on inspection by an expert technician. The technician inspects the crown, beads, sidewall and interior to make sure every tire meets high standards of we have set quality and the high expectations of our customers.
4| Extrusion Station
The extruder machine ensures that the uncured cushion gum rubber is placed upon the casing with uniform thickness. The extruder machine can adjust to the width of the tire, allowing us to retread more tires per hour. The cushion gum rubber is now ready to accept the tread in the tread building station.