Root cause analysis for warming delay of resilient solid tire heel compound during manufacturing

Warming of rubber compounds is carried out using warming mills to improve the processability of the tyre compounds before production. Delaying warming process causes production losses in several terms. Therefore, an experiment was set up to study the root causes for the warming delay that occurs when warming solid tyre heel compounds in warming mills. Brainstorming sessions were used and the maturity of the heel compounds and nip size of warming mill were identified as the main causes for the warming delay. The maturity time of the heel compounds varied as 6, 12, 24, and 48 h while the nip size of the mill varied from 7 to 10 mm at 1 mm intervals. The results of the two-way ANOVA highlighted that there was an interaction between maturity time and nip size on warming delay. Overall, the warming time can be reduced to 6 minutes; which was 8 to 10 minutes previously when using 9 mm nip size in the warming mill and maturing of the compound for 48 h.