Case Studies
Main Cylinder Upgrade
Challenge
Issue
Chesterton was challenged by a large global tire manufacturer to help reduce downtime, eliminate scrapped product and improve production of their Banbury® mixers.
OEM rubber rod stacked set and piston-cup were leaking prematurely, causing unplanned downtime and slowing down production in the making of one batch.
- Average cycle time for one batch = 130 seconds
- 8 hour shift produced 221 Batches
- Pressure: 7 BAR / 100 psi
- Temperature: 65° C / 150° F

Close up view of Banbury mixer main hopper cylinder (558 mm / 22 inch dia.) while in operation.
Solution
Recommendation
Chesterton recommended a complete sealing solution during cylinder rebuild which included replacement of the wiper, rod seal, and piston seal.
- Chesterton® K Piston-cup – Rugged construction with a supporting brass disc, molded into the base to maximize performance
- Chesterton® 8K Stacked Set – Pressure sensitive, custom molded stacked set
- Chesterton® 5K Wiper – Custom wiper blocks contaminants from entering system
- Chesterton® AWC 800 – Thermoset wear resistant material is able to offset equipment scoring

Damaged rubber OEM piston-cup seal replaced by Chesterton’s 7K piston-cup in AWC 800.
Results
Improved Performance & Reliability
The Chesterton sealing solution had a significant impact on production. The customer recorded the following:
- Average cycle time improvement = 121 sec.
- Cycle time saving = 9 sec. / batch
- Production after upgrade = 238 batches
- Gained 17 batches per 8-hour shift
- 21 shifts per week
- 357 batches per week gained
- Tonnage of rubber = 91.3 (182,600 lb) per/wk
All 6 Banbury mixers at this plant have since been upgraded to the Chesterton sealing solution.
MTBR increased: 10X

Rebuilt Banbury in operation with the Chesterton sealing solution.