Improve with mechanics retreading tread rubber wear
Addtime:2015-08-18 11:24:19 Source:兰溪荣恩铝轮有限公司 Hits:
Treadwear is the key characteristics of tire life, tread rubber wear is a measure of product quality and use features an extremely important physical and mechanical properties. Traditional methods to improve the wear resistance of the tread rubber retread tires always has two ways, depending on the chemistry of the best recipes and the corresponding compound of cure, but there are more of mechanics methods. Author Practice and Experience retread technology work for many years, describes how to use the method to improve the mechanics of the tread rubber retread tires wear:
1, rubber mixing and treads
Adopt internal mixer retread tread compounds, carbon black and other ingredients evenly dispersed, can improve retread tread compound physical and mechanical properties, which also includes the wear resistance. Retread tread strip from the extruder lip plate pushed out, in addition to semi-finished part geometry to meet needs, due to the mix without tension and dense non-bubble, but also improve the wear resistance of the tread rubber retread tires.
2, the degree of cure and the internal pressure of the medium
Retreading tread rubber due to sulfur or persulfate will affect the abrasion resistance. If the vulcanizing pressure medium cold retread tread rubber outer mold temperature sided heating, since tires are thick products, to make repairs cave sizing and pad surface vulcanized rubber materials are in place, the curing time is relatively long in order to achieve the desired bonding strength with the carcass. Typically more than twice the internal pressure medium hot curing process time, so tread rubber surface greatly persulfate, will inevitably affect the wear resistance. After the pressure of the media may use the vulcanizing hot water both inside and outside heating, curing time by half, the tread rubber over the surface of the sulfur components greatly reduced, but also improve the wear resistance of the tread rubber retread tires.
3, scale mode selection pressure and internal pressure
Green tire mold size is selected to adapt to the size of the mold, the size relationship between the embryo and fetus actual pressure inside the mold, if the tire diameter is too small or too large diameter die, consumed most of the internal mold pressure water tube embryo and fetal done, tires actual embryo and in-mold pressure is being reduced, the internal pressure values shown in the table is just a false image. In "diameter calculating method" choose tires with mold, usually after conversion tire and die diameter difference just leave 6 to 12 mm, the inner mold lug only take a small value, internal mold longitudinal pattern of desirable large value, an increase of the actual pressure equal to indirectly enhance the internal pressure vulcanization, but also improve retread tread rubber wear.
Even with the election tire mold very reasonable, by an appropriate increase in the vulcanizing pressure, can increase the compactness of vulcanized rubber, retread curing the inner pressure from 1.1MPa up to 1.5MPa, cast curing the outer mold tolerance there is no problem, The internal pressure hot water safer than using compressed air. Vulcanized directly increasing the internal pressure, but also can improve the wear resistance of the tread rubber retread tires.
4, section width and diameter variables
After tightening the use of long tread rubber compound to improve wear resistance. Because of nylon bias tires section width has greatly exceeded the nominal section width of the tire, the inner mold retread tire section width design is less than the nominal section width, with "diameter calculation method" with the amount of tire mold, green tire section width beyond the mold section width That portion included in binary a diameter, after closing the mold without internal pressure situations green tire sectional contour of their own to be adjusted, that is manifested in oppression sidewall Tingshen diameter. When Kai mold section width, although not fully recovered, and the diameter is clearly shrinking. Tire to use and expand the section width, diameter extension is being suppressed, the tread rubber in the unstretched condition use, both puncturing and abrasion resistance.
Wire meridian tire tread can turn "long squeeze" green tire with a tire mold claim amount after clamping sidewall leave some slack degree meridian, the internal pressure of about 75 ° steel belt intersecting with the "scissors effect" the belt layer is still some stretching rate, the diameter of the rear tires start to die back while reducing tread rubber were tightening, when inflated use steel radial tire, the external diameter not done, thus tightening the tread condition more resistant to puncture tie, but also improve the wear resistance of the tread rubber retread tires.
5, touchdown area and pressure distribution
Tread touchdown prints two sharp arc, crown grinding it very wearable. It is the inner mold tread arc high value is too great a certain relationship. Or tread crown within a touchdown actual grinding small area, and crown width of the groove pattern is too large and the angle is too large will strike a relationship. Further pressure is too high, the pressure within the tread footprint is too large, and the shoulder touchdown pressure force and is too small, there will be sharpened crown phenomenon. Or the number of lug section is excessive pitch a bit too small relationship. Use ordinary road driving wheel lug relatively resistant, due to the plate-like lug was, after gassing can inhibit tread throw high, relatively flat tread arc (but moderate, or prone to shoulder empty drum kits or shoulder crack quality problems ), a more balanced tread pressure will be more wear-resistant. Tires should be kept in the buffer layer at the big mill, has good buffer layer can be suppressed tread the red crown. Portrait of the mold than the lug pattern but also to reduce the width of the mold section and the corresponding expansion of the inner diameter of the die, the amount of tire mold with a mold of the appropriate change to take maximum tire diameter and die diameter difference, it can be modified within the finished retread outline lumen after vulcanized tread contour section was "upside down egg-shaped", resulting in the crown Tingshen already in place, tire use because only extends the cross section and the shoulder, rather than expansion of the crown top, you can overcome the crown throw high and abnormal widening of the longitudinal grooves of the phenomenon, so tread wear-free acceleration, but also improve the wear resistance of the tread rubber retread tires.
6, flowers block motility and rubber hardness
Tread groove as too close too deep then the block area and volume will be smaller, reducing the block / groove ratio, it means less rubber bear proportionally increased strain, hit the ground crawling process large blocks, it It will cause drag to wear. Or tread rubber hardness low, and will increase the peristaltic touchdown block, in addition to increased rolling resistance and hysteresis loss, it will also cause the block to wear drag zigzag, accelerated the unit amount of wear of the tread rubber. Also insufficient pressure can cause wear and tear like this. Therefore, the design of the mold block truck tire tread area is usually 75 to 80% of the tread for proper hardness is set within a 62 to 68 degree range when the tread rubber formulation depending on the conditions of use are more appropriate, but also can improve the wear resistance of the tread rubber retread tires.