Abstract:
Solid tyres are non-pneumatic tyres which are not filled with air. It consists of major three
layers such as heel, cushion, and tread. The main steps of the solid tyre manufacturing
process are compound warming, compound feeding, tyre rolling, curing, and final
inspection. During compound warming, the specific gravity of the warmed compound is
tested. According to that value, the required mass of compound for tyre is measured. Then
It is transferred to the feeding mill and after that, it is transferred to tyre rolling. In the
solid tyre manufacturing process, the specific gravity of the warmed compound should be
measured before the tyre rolling. The current production process takes a total of 7 min for
measuring specific gravity, which is higher than tyre rolling time. So, the current specific
gravity measuring system is un-effective for the process. If the weight will be less than
the required amount, tyre can be scrapped. It leads to economic losses to the company.
Therefore, minimizing the total time for specific gravity measuring is important to
increase productivity. In this research, eight types of experiments were designed to find
the optimum time for a specific gravity measuring process. In each experiment major four
parameters were considered, such as curing temperature, curing time, cooling water
temperature, and cooling time. In this experiments three different curing temperatures
(180 ⁰C, 190 ⁰C, 200 ⁰C), two different curing times (2, 3 min), two different cooling
water temperatures (30 ⁰C, <10 ⁰C) and five different cooling times (0, 1, 2, 3, 4 min)
were used to test the specific gravity of the compound samples under 8 different
experiments. The results revealed that the optimum curing temperature is 190 ⁰C, curing
time is 2 min., cooling time is 2 min., and the cooling water temperature is <10 ⁰C. The
total time takes by specific gravity measuring could be minimized to 4 min. It would be
profitable for the company in many ways compared to the current 7 min operation.
Keywords: Cooling time, Curing time, Curing temperature, Specific gravity, Tyre
manufacturing
