Study On Vulcanization Process Of Motorcycle Tire

After decades of development,the scale of tire industry and quality of its production in China have been greatly improved.However,many domestic tire manufacturers have unscientific methods to formulate vulcanization conditions,which has a great effect on the performance of tires.In the tire production process,vulcanization is a crucial procedure,which not only directly affects the appearance quality of tires,but also plays an important role in its driving performance and safety performance.Especially for motorcycle tires,nylon 6 cords are used as the skeleton materials.The disadvantage of nylon 6 cords is that they have poor temperature resistance,which turns yellow at 150? for 5 hours and begins to soften at 170?.Therefore,it is of great significance to study the effect of different vulcanization process conditions and vulcanization temperature on tire performance.In this paper,the temperature change and vulcanization degree of the tire under the conditions of full steam vulcanization,steam plus air vulcanization and steam plus nitrogen vulcanization were investigated by the vulcanization temperature measurement technology,and the performance of finished tire was tested.In addition,the influence of the temperature of the cord layer on the performance of the tire during vulcanization was studied.The results showed that tires with lower cord temperatures(163?)have 33.3%higher strength performance and 23.7%higher durability than tires with high cord temperatures(169?).Hence,controlling the curing temperature of the cord layer is critical to the performance of a motorcycle tire.The temperature measurement of vulcanization for three different vulcanization process conditions was studied.The results showed that there is a temperature difference between the upper and lower molds under different process conditions,and the temperature difference is related to the time of the passage of steam in the capsule during the vulcanization process.The temperature difference of the full steam vulcanization process is the highest(6.2?),and a relatively close temperature difference(2?)was observed under the steam plus air and steam plus nitrogen vulcanization process.Meanwhile,the performance of tires under three vulcanization process conditions were also compared in this study.The results showed that the strength?durability and hydraulic blasting safety factor of the tire under steam plus nitrogen vulcanization process is 13.7%and 41.4%?7.5%and 56.2%?36.7%and 46.3%higher than that of the steam plus air vulcanization process and the full steam vulcanization process,respectively.Obviously,the test performance of the tire under steam plus nitrogen vulcanization process is better than the other two vulcanization processes.To further improve the performance of the tire,the influence of the temperature of the cord layer on the nylon 6 cord was also studied during the vulcanization process.The results showed that the breaking strength?durability?hydraulic blasting safety factor and strength of nylon 6 cords at higher temperatures(169?)have declined by 11.4%?23.7%?16.1%and 25%than that of lower temperatures(1630?),respectively,which indicated that the high temperature of the cord layer would damage the strength of the nylon 6 cords in the vulcanization process,resulting in a decline in the performance of the tires.