Tyre Retreading Process (General)
 |
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 like the Spectra or general inspection machine.
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. Collaboration with international leaders like MATTEUZZI enables Newera to build computerized world class equipment under license for Asia.
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. The pre-cured tread rubber is then applied with the building machine. This is called the building process.
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. Modern plants have their casings hoisted by monorail systems.
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.
The monorail & hook system increases productivity by cutting down on chances of casings contamination and allows for faster loading and unloading of tyres. This increases your work place safety and productivity.
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.