When designing a tire, the value of the compression ratio of the bead ring portion is too large, the width of the ring portion of the die, and the diameter of the bead ring are too small, resulting in excessive distribution of material in the bead ring portion during construction. The drums are hemispherical during molding, and there are many materials on the side of the bead, but not on the other side. When the vulcanized water tire is not properly fitted; the wind pressure is too low, the water tire can not fully stretch; water tire stereotyping is not correct. Measures to adjust the wire ring wire arrangement, reduce the width of the wire ring; increase the number of wire layers, increase the diameter of the wire ring The wire ring diameter is the sum of the diameter of the mold steel ring and ply. Ensure that the semi-finished bead area is compacted, and no bead voids or edges are allowed. Ensure that the cut angle of the cord is accurate, the length of the cord fits properly, and the tension of the cord is stable. The center line is aligned when forming the 2 curtain cylinders to prevent the side of the bead area from excessive material due to the hemispherical warp. Semi-finished tires are evenly coated with talcum powder; water tire surface release agent is evenly sprayed. Curing when the wind pressure is not less than 0.4MPa, and a number of stereotypes; shape a good semi-finished products in the stereotypes disk to maintain 23min, in order to facilitate the full expansion of the water tire; ensure the water tire stereotyped. Tire side out of the large-size agricultural tire sidewalls are prone to plastic blister defects, blisters, gas stasis and viscera. Cause Analysis The distribution of semi-finished sidewalls is irrational and there is a local thin phenomenon. During the molding, the height of the cut edge of the semi-finished product is too large, and the local material distribution is too small, especially at the assembly line. In the molding, the two rear press rollers have different angles, and the press roller presses the sidewalls out of the deep marks, resulting in irregularities on the sidewall surface. The tire blank was stained with a separating agent and oil, and it was not wiped clean before use. Shaped fashion wiring joints cracked. The water on the surface of the mold has not been cleaned. When vulcanized, moisture evaporates but is not discharged to produce blisters. This type of enamel often has rust around it. There are few mold vents and the distribution is unreasonable or the vent holes are blocked, so that the gas can not be discharged, resulting in the lack of surface bright shiny gel. Measure: The sidewall size is matched with the sidewall thickness of the finished product. The sidewalls are fixed once at the time of molding, the butt joints are connected and the cutting edge height is the same; the sidewalls shall not have the phenomenon of thinning or rotting after the pressure roller, and they must not be tied when they are gartered. Bad traces of tread. Before the mold is filled, the moisture in the mold is removed, especially the water in the upper mold vent. Increase the number of mold vents, and regularly through the mold vents. Strengthen the drying process and ensure the stereotyped storage of the three-flat tires. Stabilize and increase the vulcanization pressure, the internal pressure is not lower than 2.5MPa, the circulating pressure is not lower than 2.2MPa. Replace the water-separator with regular intervals; ensure that the surface of the shaping plate is clean, avoiding the formation of a good green tire, which is stained with oil in the transportation process; The surface of the billet is wiped clean and then loaded. Heavy tires on the sidewalls of large-sized agricultural tires with heavy sidewall cracks are prone to cracks in the skin, and the cracks are mainly located at the anti-rubbing line of the tire and distributed along the tire circumferential direction. Reason analysis The two rear rollers have different angles during molding. The tire blanks are seriously deformed. After the deformation and bending, the concaves are formed. The inside is easy to harbor dirt, and the green tires are not cleaned before the curing. The good shape is not repaired. Well, dents and patches often appear heavy. Molding operation time is long; mold temperature is too high; tire blank stays in the mold for too long; heating too fast; the material scorch time is too short. When the semi-finished product is shaped, the water tire is not fully stretched in the green tire, resulting in insufficient stretch of the carcass ply, resulting in pleating of the tire sidewall of the finished tire. Measures to reasonably arrange the production of green tires, no overstocking is allowed, no stacking is allowed during transportation and storage; the drying chamber and the surrounding of the setting machine are kept clean; the spacers on the surface of the tires are dried and then set; the setting plate is shaped. The oil is wiped clean to prevent the green tire from being stained with oil. Before the vulcanization of the green tire, it should be wiped cleanly; for the green tires with good shaping but dents, the dents should be wiped clean and repaired. Improve the formula of sidewall rubber and reduce the amount of accelerator NOBS to prolong the scorch time of the rubber and increase the fluidity of the rubber. Extrusion temperature of the extruder does not exceed 110 to prevent early scorch of the rubber. Strengthen the tire cooling after vulcanization, the mold temperature is reduced to 80 or less, and improve the worker's operating efficiency, shorten the residence time of the tire in the mold cavity and prevent the tire from being cooked. It is strictly forbidden to continue production in the case of inconsistency between the two rear press rollers. Ensure the wind pressure of the setting machine. Tyre cracking and carcass discoloration Large-size agricultural tires are prone to cracking and aging of the sidewall during prolonged exposure to the outdoor environment, accompanied by surface discoloration. Cause Analysis Compounding is not uniform, and the color of the compounding agent is mixed and precipitated on the surface of the compound. The oxidation of the antioxidant on the sidewall surface produces a reddish-brown substance that causes the sidewall surface to be reddish-brown. After the aromatic oil precipitates out of the rubber surface, it reflects light under sunlight, causing a large color difference in the tire. Concluding remarks By adopting the above-mentioned measures, we have overcome the defects in appearance quality of our company's large-size agricultural tires, such as the toe rubber edge, the sidewall outburst, the sidewall thick skin crack, the tread collapse, the discoloration and deformation of the carcass, and the finished tire appearance. The pass rate has been further improved, the market reimbursement rate has been significantly reduced, user satisfaction has been greatly enhanced, and social and economic benefits have been good. Prilled Ammonium Nitrate,Tungsten Chemical Formula,Tungsten Oxide Acid,Yellow Tungsten Trioxide HUNAN ZHONGNAN ANTIMONY&TUNGSTEN TRADING CO.,LTD , https://www.zhongnanats.com