KOBE, Japan (May 12, 2003) — Sumitomo Rubber Industries Ltd. has developed and put into operation a cell-based tire production system that integrates the manufacturing process from component preparation to tire curing.
Dubbed Taiyo — Japanese for sun — the new system produces tires with no measurable joints, a development Sumitomo claims results in a 50-percent improvement in high-speed uniformity and balance while also improving plant flexibility.
Development of the first-stage prototype, which integrated the component preparation stages, dates back to 1996, Sumitomo said, with initial production of passenger tires starting in 2000 at the firm's Nagoya, Japan, plant. Curing was then integrated and the first complete Taiyo cell began operation in July 2002 at the Shirakawa, Japan, plant. The firm has made 500,000 tires in the cell and sold them in Japan.
Sumitomo is installing a second cell at Shirakawa and a third cell, dedicated to sport-utility vehicle and run-flat tires, is earmarked for the Izumi-Ohtsu, Japan, plant of Sumitomo's Ohtsu Tire unit by June 2003. The production of motorcycle and radial truck tires with Taiyo is in the planning stage.
The firm did not disclose the cost of developing Taiyo, but said the capital investment payback period is shorter than with conventional equipment.
Among the claims Sumitomo makes for Taiyo are:
* A 5-percent reduction in tire weight due to tighter tolerances on rubber thickness;
* A more rigid casing due in part to the use of micro fibers compounded into the sidewall rubber;
* Greater flexibility in design and production;
* Enhanced investment efficiency, in that a Taiyo cell can produce 1,000 tires of eight different sizes a day; and
* Improved operating efficiencies from a smaller plant size, reduced intermediate inventories and a 35-percent drop in energy consumption.