Some standard content:
National Standard of the People's Republic of China
Retreading and repair of tyres (radial tyres) Retreading and repair of tyres (radial tyres) Chapter 1 Retreading tires
1 Explanation of subject content and applicable scope
GB1464693
This standard specifies the technical requirements for tire selection of used tires for retreading and the technical requirements, test methods, inspection rules and markings for finished retreaded tires after retreading.
This standard applies to the retreading of pneumatic tires for cars, trucks and trailers with radial structure. 2 Reference standards
GB/T521 Method for determination of tire outer edge dimensions
GB2977 Truck tire series
GB2978 Passenger car tire series
GB/T4501 Truck tire durability test Method (drum method) GB/T4502 Passenger car tire durability test method (drum method) GB/T7034 Passenger car tire high-speed performance test method (drum method) GB/T7035 Light truck tire high-speed performance test method (drum method) GB9768 Tire Use and Maintenance Regulations
3 Terms
3.1 Hole size: refers to the size of the bottom of the hole after polishing. 3.2 Nail holes: refers to hard holes with a hole diameter within 6mm. 4 Tire Classification
4.1 Carcass Classification: In the technical requirements for radial tire retreading and tire selection, the radial tire carcass is divided into two levels: A and B according to the integrity of the tire carcass.
4.2 Finished tire grading: In the technical requirements for retreaded tire products, the finished products are divided into first-class and qualified grades based on the integrity of the carcass and the performance indicators achieved by the retreaded tire products. Retreaded tires with Class A carcass are designated as first-class products, and retreaded tires with Class B carcasses are designated as qualified products. The specific technical requirements for finished products are as follows: Appearance quality, outer edge size, and durability indicators are not ranked, and those that meet them will be classified as qualified products. First-class tires for cars and light trucks require high-speed performance testing. The guaranteed mileage for first-class and qualified products shall be as per 6.6. 5 Technical requirements for retread tire selection
5.1 Class A retread carcass must meet the following requirements. 5.1.1 The remaining pattern at the tire crown measurement point: not less than 1.6mm for car tires, not less than 2mm for light truck and truck tires. Local wear shall not damage the belt layer.
State Bureau of Technical Supervision approved 281 on September 09, 1993
Implemented on August 01, 1994
5.1.2 Aging cracks are not allowed on the sidewalls.
GB14646
5.1.3 The depth of mechanical damage cracks on the sidewall shall not expose the carcass cords. 93
5.1.4 No hollowing or delamination is allowed in any part of the tire, and no wires or jumpers are allowed in the tire. 5.1.5 The bead wrapper must not be mechanically damaged or worn, and the bead is not allowed to be damaged, deformed, or hollowed out. 5.1.6 Car tires are not allowed to have nail holes or holes; light truck tires are allowed to have nails in their crowns. One hole with a diameter of less than 6 mm, or two holes with a diameter of less than 3 mm; truck tire crowns are allowed to have one hole with a diameter of less than 10 mm, or three nail holes. 5.1.7 Tires to be retreaded must be unretreaded tires. 5.2 Class B retreaded carcass must meet the following requirements 5.2.1 The remaining tread pattern at the tire crown measurement point is allowed to be ground flat, and the belt layer of light truck tires and truck tires is allowed to be partially worn by one layer.
5.2.2 The tread shoulders of passenger car tires are not allowed to be hollow. The two shoulders of truck tires are allowed to have a small area of ??partial hollowing, and the single side width of 9.00R20 and below specifications shall not exceed 10mm; the unilateral width of 10.00R20 and above specifications shall not exceed 20mm. 5.2.3 Slight aging cracks and cuts are allowed on the sidewall, but they must not be as deep as the ply. 5.2.4 Partial voids are allowed between the sidewall rubber and the carcass, and the cumulative length does not exceed 1/16 of the circumference. No rolled wires or jumpers are allowed in the tire. 5.2.5 Minor mechanical damage and wear are allowed on the chafing fabric. The bead is not allowed to be damaged, deformed or hollowed out. 5.2.6 Slight rust is allowed on the steel cord in the damaged area, and no spreading hollowing is allowed. The allowable tire punctures and the number of perforations are shown in Table 1 and Table 2. 5.2.7
Table 1 Maximum size and number of permissible punctures for radial tires for cars and light-duty trucks Permissible punctures for tires
Tire type
Car tires
Light truck tires
Tire specifications
7.00R20-8.25R20
9.00R20~10.00R20
11.00R20 and above specifications
maximum size
sidewall and shoulder
(cross-cut cord)
25
crown||tt ||10
25
Measure the shortest distance from tire toe to
hole
60
Maximum size and number of tire punctures allowed
Maximum size
sidewall and shoulder
(cross-cut cord)Www.bzxZ.net
35
45| |tt||55
Technical requirements for finished retreaded tires
6
6.1 Appearance quality
Tire crown
40
45|| tt||50
The appearance quality of the finished retreaded tires should comply with the requirements in Table 3. Measure the shortest distance from the tire toe to the
hole along the inside of the tire
70
90
110
mm
The maximum allowed for the tire is || The number of holes for tt||
2
mm
The tire allows the maximum number of holes for
2
3
4
285
serial number
2
6
8
10
12|| tt||Defect name
Tread crown rubber edge
Model seam misalignment
Incomplete pattern
Tread pattern collapse
Spongy shoulder surface
Lack of rubber in the tread pattern
The rubber at the base of the pattern is too thin
Tread repair
Sidewall model marks
Pits and solid drums in the tire| | tt |
Sedan and light truck tires
The base thickness shall not be greater than 1.5mm
not greater than 1.0mm
not allowed
not to exceed the pattern pitch number 1/10;
does not exceed 1/3 of the depth of the pattern groove;
shall not drop pieces, and the base of the pattern shall not crack
is not allowed
The depth shall not exceed 1.5 mm; the cumulative length is not greater than 1/6 weeks
not allowed
not allowed
the depth is not greater than 2mm; the length is not greater than 1/5 weeks not allowed
crown The depth is not greater than 30% of the tread depth; the thickness of the base of truck and trailer tires
is not greater than 3.0 mm
tt||The total length shall not exceed 1/3 of the circle and shall not exceed 1/3 of the depth of the pattern groove.
No pieces shall fall off and the base of the pattern shall not crack
The depth shall not exceed 1.5mm and the length shall not exceed 1/ The depth of 5 weeks shall not exceed 4mm; the cumulative length shall not exceed 1/4 of a week; file marks are not allowed to be exposed
It is allowed to rework according to the original pattern once, and the length shall not exceed 1/5 of a week
The depth shall not exceed 3mm, and the length shall not More than 1/5 week, the depth and height are not more than 3mm respectively; the length is not more than 1/5 week
The depth of the sidewall is not more than 40% of the sidewall rubber thickness, and no more than 2 places are not allowed||tt| |Note: ① Within the allowed range, the number of appearance defects of qualified products shall not exceed 5. ②Retreaded tires are considered unqualified if there are voids or sponginess between the components, the bead is damaged and deformed, the damaged areas are not repaired, or there is insufficient sulfur or severe over-sulfur that causes the rubber to age.
6.2 Outer edge dimensions
The maximum cross-sectional width and maximum outer diameter of the finished retreaded tire shall not exceed the maximum use size of tires of the same specifications in GB2977 and GB2978.
6.3 High-speed performance
The high-speed performance test of refurbished passenger car and light-duty truck tires shall be tested according to the test methods of GB/T7034 and GB/T7035 respectively. The test conditions are as specified in Table 4. 286
Tire type
Test inspection parts
Test stage
2
3
4
6.4 Durability| |tt||GB14646-93
Table 4
Car tires
Light truck tires
The charging pressure is the air pressure corresponding to the maximum load; the test load is the maximum load ×0.88 Drum speed, km/h
80
90
100
110
Time, min
120||tt ||30
30
30
Drum speed, km/h
60
o
80
90 | After a 47-hour durability test, the vehicle is qualified if there are no voids, cord breakage, cord layer cracks reaching the lower cords, joints cracking the tread, or sidewall rubber pieces falling off or cracking, etc. during the visual inspection. 6.5 Tread wear marks
Each retreaded tire should be provided with no less than 4 tread wear marks at equal distances along the circumferential direction from which the remaining depth of the tread groove can be observed (1.6mm for car tires and 2.0mm for truck tires). logo. Symbols indicating the location of the tread wear marks must be engraved on both sides of the tire tread. For car tire carcass marked with high-speed tire grade "S", "H" or "V" signs before retreading, the high-speed signs should be removed. 6.6 Guaranteed mileage
6.6.1 Under the condition that the user complies with the relevant provisions of this standard and GB9768, within two years from the date of product production, the manufacturer shall ensure that the tread pattern of each tire is worn flat or normal The domestic driving mileage before damage is: first-class products reach 70% of the guaranteed mileage of new tires, and qualified products reach 60% of the guaranteed mileage of new tires. 6.6.2 Retreaded tires used on roads below grade four, such as sidewalks, construction sites, mining areas, etc., do not guarantee mileage according to the above conditions. 7 Test Methods
7.1 The appearance quality of Grade A and B carcass selection and finished retreaded tires can be inspected by ruler, visual inspection, tapping or X-ray inspection. 7.2 The outer diameter and cross-sectional width of the finished retreaded tire after inflation are measured according to GB/T521. 7.3 The high-speed performance test of the finished retreaded tire shall be determined according to the test methods of GB/T7034 and GB/T7035 and the test conditions in Table 4.
7.4 The durability performance of finished retreaded tires is measured according to GB4501 and GB4502. 8 Inspection Rules
8.1 Finished retreaded tires shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. 8.2 The finished retreaded tires should be inspected one by one for appearance quality and whether the high-speed markings have been worn away using a ruler, visual inspection, listening, or X-ray. If it does not meet the standard requirements, it can be rebuilt once. If it reaches the standard after repair, it is still a qualified product. 8.3 Each tire retreading enterprise must check the outer edge dimensions of retreaded tires one by one in accordance with the provisions of 6.2 of this standard. If it exceeds the requirements of 6.2, it shall be deemed as unqualified product.
8.4 Durability and high-speed performance test:
The finished radial tires after retreading must be sampled for durability testing. Among them, first-class tires for passenger cars and light-duty trucks are sampled for high-speed performance testing. The samples are drawn separately according to the production batch. That is, 1 tire is taken for every 6,000 tires; for enterprises that turn over less than 6,000 tires of this type annually, the annual output is calculated as one batch. If they fail, two more tires from the batch should be taken for re-inspection. If the re-inspection still fails. 287 | | tt | | GB14646-93 | 9 logo
9.1 Tire retreading company name.
9.2 Symbol of the position of the tread wear mark.
9.3 Tire finished product grade (i.e. - equal grade, qualified product). 9.4 Inspection of seals.
The finished product of 9.5 retreaded radial tires must be marked with 9.1 and 9.2 mold impressions; the rest shall be stamped with inspection seals and first-class and qualified product seals after passing the inspection. The seal must be a material imprint that cannot be washed away with water. 9.6 First-class retreaded tires for passenger cars can be driven on highways at a speed of no more than 110km/h, and light-duty truck tires can be driven at a speed of no more than 90km/h. Qualified products are not suitable for high-speed driving on highways. Chapter 2 Repair Tires | Technical requirements, test methods, inspection rules and markings for finished tire products.
This standard is applicable to the repair of pneumatic tires for cars, trucks and trailers with radial structure. 11 Reference Standards
GB2977 Truck Tire Series
GB2978 Passenger Car Tire Series
HG/T2186 Tire Hydraulic Test Method
12 Terms
12.1 Puncture Size: refers to the size of the bottom of the hole after the mushrooms are punched. 12.2 Nail holes: refers to hard holes with a hole diameter within 6mm. 13 Technical requirements for tire selection of repaired tires
13.1 The remaining tread depth at the tire crown measurement point shall not be less than 1/3 of the new tire tread depth. 13.2 No voids are allowed on both shoulders of passenger car tires, light truck and heavy truck tires A small area of ??space is allowed on both shoulders. Its single side width shall not exceed 10mm for specifications 9.00R20 and below, and shall not exceed 20mm for specifications 10.00R20 and below. 13.3 Slight aging cracks and cuts are allowed on the sidewall rubber, but they must not be as deep as the ply. 13.4 Partial voids are allowed between the sidewall rubber and the radial carcass, and the cumulative length shall not exceed 1/16 of the circular length. No wires or jumpers are allowed in the tire.
13.5 The bead wrapper is allowed to have slight mechanical damage and wear, and the bead is not allowed to be damaged, deformed or hollowed out. 13.6 Slight corrosion of the steel wire in the damaged area is allowed, and no spreading hollowing is allowed. 13.7 The maximum size and number of holes allowed for radial tires are shown in Table 5 and Table 6. 288
Tire Type
Car Tire
GB14646--93
Table 5. Maximum size and number of holes allowed in radial tires for cars and light trucks. Maximum size of tires allowed to be punctured
sidewalls and shoulders
(cross-cut cords) || tt||Light truck tires
Tire specifications
7. 00R20 ~8. 25R20
9.00R20~10.00R20
11.00R20 and above specifications||tt ||25
Tread crown
25
Measure the shortest distance from the tire toe to the
hole along the inside of the tire
60
Table 6 Maximum size and number of holes allowed in truck radial tires Maximum size of tires allowed to be punctured
Sidewall and shoulder
(cross-cut cord)
35
45
55
14 Technical requirements for finished tire repairs
14.1 Appearance quality of finished tire repairs
Tire crown
40||tt ||45
50
Measure the shortest distance from the tire toe to
hole
70
90
110|| tt||14.1.1 No parts of the tire that should be repaired are omitted, and all parts that can affect the service life of the tire have been repaired. 14.1.2 The repaired area of ??the tire must be tightly bonded, and no voids are allowed between the liner and the carcass. The maximum number of holes allowed in the tire is
2
tires The maximum number of holes allowed
3
4
mm
mm
14.1.3 The repaired tread pattern is clear , If the tire crown repair area exceeds one pattern, a similar pattern must be carved, preferably the same pattern. If tread blocks are used for repair, the same pattern should be used. 14.1.4 The repair glue is not allowed to have aging cracks, lack of sulfur or excessive sulfur. 14.1.5 The unevenness of the repaired tire lining shall not exceed 5mm. 14.1.6 The bead diameter must remain the original tire diameter, and no deformation of the bead is allowed after repair. 14.2 Tires repaired with pads due to damaged holes should undergo a hydrostatic test. 14.2.1. Padded and repaired passenger car tires should be able to withstand a water pressure test of no less than five times the maximum inflation pressure of radial tires of the same specification level specified in GB2978.
14.2.2 Padded and repaired light-duty truck tires and truck tires should withstand a water pressure test that is no less than three times the maximum inflation pressure of radial tires of the same specification level specified in GB2977. 15 Test Methods
15.1 The appearance quality of repaired tires can be tested by visual inspection, ruler and tapping or X-ray inspection. 15.2 The tire water pressure test method shall be determined in accordance with the relevant provisions of HG/T2186. 16 Inspection Rules
16.1 The finished tire after repair shall be inspected by the quality inspection department of the production unit in accordance with this standard. 16.2 The appearance quality of the repaired tire products should be checked one by one by visual inspection, ruler and tapping or X-ray inspection. If it does not meet the standard requirements, it can be rebuilt one after another. If it reaches the standard after repair, it will still be a qualified product, otherwise it will be a unqualified product. 289 | | tt | If the tire is still unqualified, the batch of repaired tires will be deemed to be unqualified. 17 mark
17.1 Inspection seal (contains the name of the tire retreading company and whether it is a qualified product). 17.2 To repair the marks on the tires, use a substance that cannot be washed away with water. Additional notes:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the National Tire and Rim Standardization Technical Committee. This standard is drafted by the Guilin Rubber Industry Design Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiaoheng and Lu Younan. This standard refers to the British standard BSAU144C--1988 "British Passenger Car Tire and Truck Tire Retreading Standard". From the date of implementation of this standard, the original professional standard ZBG41Q01-86 "Retreading and Repairing Tires (Radial Tires)" is invalid. 290
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