Regular tire refers to truck or bus tire, of which the size is generally 8.25R20----318/80R22.5.
Hot retreading: suitable for tires running on poor road conditions
Cold retreading: suitable for tires running on good road conditions.
At present, pre-cured retreading is the main choice for regular tires.
1. Rich experience and excellent technique with over 30 years retreading experience. China's largest tire retreading equipment manufacturer.
|Typical Process Flow|
Inflation Testing Inspection – Pressure Testing Machine CQJ
Non-destructive Inspection - Shearography
Visual Inspection– Inspection Spreader KTJ
Non-destructive Inspection - Shearography
Tire inspection spreader is used to inspect the casing from inside to outside to evaluate the safety of the tire and make the decision whether the tire can be retreaded. Find and mark all visible and repairable defects on the acceptable tires.
Why we need to inspect before retreading?
Tires are collected from various areas and each tire’s condition is different. To ensure the retreading quality of each tire, we must check the collected tires.
Tires are not acceptable if the following conditions happen:
* Sidewall damage is beyond repair limits.
* Bulges caused by separated or broken part of wires on the sidewall.
* Wires of sidewall bruise breaks, contusion and blow outs, etc.
* Bent, distorted, torn, burnt, broken, deformed and excessively senile beads.
* Deep & rusty penetrated steel wire cuts which cause separation.
* Ply separation, excessive damage and extremely large orifice around crown area.
inspection spreader for Michelin factory
Pressure Testing Machine CQJ is used to test the tire strength and check the tire of air leaks under the high pressure with computer monitor system.
Some defects (such as the damage caused by unsubstantial or broken wires) can only be found under high pressure. Inflating pressure into the fixed tire, monitor the surface images on the computer screen.
This machine can be used to inspect precisely the following three parts of tire.
Surface: covering the light damage and cracks.
Shoulder: covering the abruption and cracks.
Sidewalls: covering the invisible cracks, broken, bulges.
Tire Buffer YLM Front View
Tire Buffer YLM Back View
Replaceable Profiling Template
This buffer is designed with profiling template to ensure buff precisely, which can buff the tread with different curvatures based on different needs by changing related template. The replaceable template decides the buffing radius and curvatures. The replaceability improves the performance and ensures the buffer can buff different size tires with different curvatures.
3. Skiving & Repair
Tire Builder YLT Front View
Tire Builder YLT Back View
The tread cutter is fixed on the frame, which consists of the articulated arm and jig saw. It is used to cut the extra flat tread to optimize length at the joint, which is convenient for operating.
(suitable for simple factory layout)
(suitable for whole factory
Envelope expander/spreader usually has two mainframes: vertical and horizontal based on clients’ specific needs and technical process. The vertical one usually works together with whole factory monorail system and turntable. The horizontal one works with steel rim loader without whole monorail system. Turntable (for inside envelope loading) Steel Rim Loader (for steel rim loading)
(for inside envelope loading)
Steel Rim Loader
(for steel rim loading)
Optional Heating System: With steam (heat conduction oil) or electricity.
Dual Control System:
Manual / PLC + manual. Touch screen available (optional).
The PLC-controlled curing chamber is with control and functions as follow:
Differentiated Pressure Control
Safety Interlocking System
Our curing chamber is completely insulated by multi-layer special aerospace insulation materials and covered with stainless steel, which ensures very low heat loss, high energy efficiency.
Hot Retreading Procedure
|hot retreading line|
1. Initial Inspection
Initial inspection for regular tires is to do visual inspection, and press testing inspection to make a decision whether the tyres can be retreaded or not.
Equipments involved: Inspector KTJ, pressure testing machine CQJ.
Buffing is to remove the old, worn tread surface. Before buffing, put tire in YLM and inflate it. Tire will rotate with buffer and tread will be buffed away by YLM to the pre-set arc.
Equipment involved : YLM buffing machine
Skiving means polishing the mendable broken parts and then repairing the small holes.
Equipments involved : skiving machine, pneumatic rubber extruder
Tire building means gluing cushion gum and suited tread to the polished tire under the help of tire builder.
Equipments involved: latex mixer, YLT builder
Vulcanization is the procedure that bonds the new casing and tread tightly. During the vulcanization the uncured rubber becomes tough and durable tread gradually. Put the prepared casing into the segment press, when the mould close and up to the certain pressure, the casing will be pressed on the mold with set pattern. Then over a period of time, the mold with pattern will be vulcanized.
Equipment involved: KGFL Segment Curing Press and KGL Frame Automatically Hydraulic Curing Press
Equipment involved: HFL segment curing press, FL two-piece curing press
6. Final Inspection
Final Inspection is to inspect all the treated tires thoroughly to make sure high quality.
Equipments involved: Spreader KTJ, CQJ pressure testing machine