Customer case studies

Roll barring is very common in the press and calendars sections with rolls that are nipped together. This example is in a Soft Nip Calendar which has two Beltex rolls nipped against a Tripass steel calendar roll. The Tripass roll is of very high-temperature oil running through it in three passes. The Beltex is a softer covered roll and can be barred fairly easily. Problems caused by Beltex roll After prolong runs the Beltex will start to bar and only get worse until it causes problems in the paper and then it needs to be removed. After removal, they have to grind the cover to remove the flat spot effects that can be seen if the light hits the roll [...]

This case is presenting a defect of a Triple Ring Bearing at the 2nd Press CC Roll. CC refers to “Controlled Crown”. This has the ability to crown or bend the roll slightly to conform to the nip that is pressing against the other roll. Expensive bearing This bearing is very expensive around 50K USD and is very large. It is called a triple ring bearing as it has two sets of rollers so there is an “outer race of the outer bearing” and there is an “inner race of the outer bearing” then there is an “outer race of the inner bearing” and then finally there is an “inner race of the inner bearing”. Trend view In the trend [...]