The current main products of Shanghai Yibin Company include: forklift tire retreading equipment, truck and bus tire retreading equipment, engineering vehicle tire retreading equipment, aircraft tire retreading equipment, including: vulcanization tank, grinding machine, tread press, rubber winding machine, Tire repairing machines, vulcanized steel rings, tire hot stamping machines, tire repair tools and other auxiliary equipment. Tread wear is a key characteristic affecting tire life. Tread rubber wear resistance is an extremely important physical and mechanical property to measure product quality and function. There are two ways to improve the wear resistance of traditional tread tires. The chemical depends on the optimum compound formulation and the corresponding degree of vulcanization, while there are more methods in mechanics. The author uses the practice and experience of many years of tire technology to explain how to improve the wear resistance of the tread rubber by mechanical methods:
1. The compounding of the rubber compound and the tread extrusion use the mixer to mix the retread tread rubber compound, and the carbon black and other compounding agents are evenly dispersed, which can improve the physical and mechanical properties of the retread tread rubber compound, which also includes Wear resistance. The retread tread rubber strip is extruded from the extrusion nozzle plate. In addition to meeting the geometry requirements of the semi-finished parts, the wear resistance of the retread tread rubber can also be improved due to the tension and compactness of the rubber mixture.
2, the degree of vulcanization and internal pressure medium tempered tread rubber under sulfur or sulfur will affect the wear resistance. If the vulcanized internal pressure medium is cold air, the retread tread rubber is heated on one side of the outer mold temperature. Since the tire is a thick product, the repaired hole bottom rubber and the gasket surface rubber are vulcanized in place, and the vulcanization time is long. In order to achieve the required bonding strength with the carcass. Usually it is twice the time of the internal pressure medium superheating vulcanization process, so the tread surface rubber is greatly over-sulfur, which will inevitably affect the wear resistance. The vulcanized internal pressure medium can be heated simultaneously inside and outside after the superheated water, the vulcanization time is shortened by half, the composition of the surface layer of the tread is greatly reduced, and the wear resistance of the tread rubber can also be improved.
3. Choosing mold size and internal pressure pressure The size of the embryo blank is adapted to the size of the inner mold, and the actual pressure between the embryo and the inner mold. If the tire diameter is too small or the mold diameter is too large, the inner embryo and the water tire are stretched. When most of the internal pressure is consumed, the actual pressure of the embryo and the inner mold is greatly reduced, and the value displayed on the internal pressure gauge is only an illusion. The tire diameter is selected by the "diameter measurement algorithm". Usually, the difference between the tire and the die diameter is only 6~12mm. The inner mold of the transverse pattern only takes a small value, and the inner mold of the longitudinal pattern can take a large value, and the actual pressure increases. It is equivalent to indirectly increasing the internal pressure of vulcanization and also improving the wear resistance of the tread compound.
Even if the tire matching mold is very reasonable, by appropriately increasing the internal pressure of the vulcanization, the compactness of the vulcanized rubber can be improved, and the internal pressure of the vulcanization vulcanization can be increased from 1.1 MPa to 1.5 MPa, and the bearing capacity of the cast steel vulcanized outer mold will not be problematic. Internal pressure and hot water are safer than using compressed air. Directly increasing the internal pressure of vulcanization can also improve the wear resistance of the tread rubber.
4, the width of the section and the diameter of the variable long tread after tightening can improve the wear resistance of the rubber. Since the cross-section width of the nylon biased old tire has greatly exceeded the nominal section width of the tire, the width of the inner section of the retreaded tire is smaller than the nominal section width of the tire. The "diameter measurement algorithm" is used to measure the tire mold, and the section width of the embryo is wider than the section width of the inner mold. The part is counted into the diameter in two to one. After the mold is closed, the shape of the cross-section of the embryo is adjusted by itself without the internal pressure, that is, the diameter of the sidewall of the compression is extended. Although the section width cannot be fully recovered when the mold is opened, the diameter is significantly contracted. The tire inflation has expanded the section width and the diameter extension is suppressed. The tread rubber is used in the unstretched condition, which is resistant to snagging and wear resistance.
The steel wire meridian tread can be “extra long tighteningâ€. The fetal tires have a certain degree of slack in the carcass after the mold clamping, and the steel belt with the inner pressure of 75° has a “scissors effectâ€. The belt layer still has a certain stretch ratio. After the mold is opened, the tire diameter is recovered and the tread rubber is tightened. When the air is used, the radial tire is not stretched due to the outer diameter, so the tread in the tightened state is more resistant. The tie can also improve the wear resistance of the tread rubber.
5, the touch area and the pressure distribution tread touches the ground and marks the two sharp arcs, the crown grinding surface is very wear-resistant. It has a certain relationship with the high value of the inner mold tread arc height. Or the actual grinding surface area of ​​the tread cap is small, and it may be related to the excessive width of the crown groove and the excessive angle of the pattern. In addition, the air pressure is too high, the pressure in the crown is too large, and the pressure on the shoulder to touch the ground is too small, and the phenomenon of crown grinding will occur. Or if the number of horizontal patterns is too large, the pitch is too small. The ordinary road drive wheel uses the horizontal pattern to be more wear-resistant. Because the horizontal pattern is plate-shaped, the tread can be restrained from being thrown high after the air is blown, and the tread is flat arc (but moderately, otherwise the shoulder space, bulge or shoulder crack quality problem is easy to occur. ), the tread pressure is more wear-resistant than the balance. The tire should also retain the buffer layer as much as possible during the large grinding, and the perfect buffer layer can also inhibit the tread crown. The inner mold of the longitudinal pattern should reduce the width of the inner mold section more than the transverse pattern, and correspondingly enlarge the inner mold diameter. The appropriate mold diameter of the tire mold is changed to the upper limit of the difference between the tire and the mold diameter, and the finished product can be modified. Contouring, after vulcanization, the cross-section of the inner cavity of the crown is “inverted egg shapeâ€, so that the crown extension is already in place. The tire inflation can only be extended by the cross section and the shoulder, and the crown can no longer be extended. It overcomes the phenomenon that the crown is thrown high and the longitudinal groove is abnormally widened, so that the crown wear is not accelerated, and the wear resistance of the tread rubber can also be improved.
6. When the flower block creeps and the rubber material tread groove are too dense, the block area and volume will become smaller. If the block/groove ratio is reduced, it means that less rubber is subjected to the proportionally increased strain. When the touch block process block creeps, it will cause traction wear. Or the hardness of the tread rubber is low, and the creep of the block during the grounding process is increased. In addition to increasing the rolling resistance and the hysteresis loss, the block jagged wear is caused, and the unit wear amount of the tread rubber is accelerated. In addition, insufficient air pressure can cause such wear. Therefore, the inner trumpet design of the tread block area is usually 75 to 80% of the tread. It is also appropriate to set the tread rubber formula according to the different conditions of use in the range of 62 to 68 degrees. Can improve the wear resistance of the tread rubber. Http://news.chinawj.com.cn Editor: (Hardware Business Network Information Center) http://news.chinawj.com.cn
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