Why Does It Matter?
Tire Building is the most complex operation in the tire factory. Multiple components are centered, applied, spliced, turned-up, inflated, and stitched – all in ever-shorter cycle times, and in many cases with no human eyes present to monitor the assembly. Component stock variations combine with machine variations to produce green tires with variations in radial runout, belt and tread snaking, lateral runout, and splice quality. Green tires with the largest geometric variations invariably produce tires with the worst cured tire uniformity and balance performance.
Since GTU records measurement for every green tire, that data can be mined to compare each run with prior runs so you can recognize trend changes.
Since overlapping splices are two-layers deep across the overlap area the result is always a high bulge across the width once the carcass has been combined with the belt/tread package, inflated and stitched. This localized RRO has associations with several cured-tire uniformity parameters:
- Excessive overlapping splices are associated with RRO and RFV and static imbalance
- Open splices risk tire failure in use.
Angles matter too. GTU data can be mined to look for changes in splice angle, an indication of a process change.