Tire Curing Bladder Coatings

The life of tire curing bladders can be increased through the application of a curing bladder treatment, which helps to protect the bladder against chemical and abrasion attack throughout its service life. This type of attack is prevalent at the surface of the curing bladders that contacts with the beads of the tires being cured. Coatings can significantly help increase average bladder life. The choice of inside tire paint can also have a positive impact on the service life of curing bladders.

A bladder treatment is a special coating that is applied to a new bladder before it is fitted into a press and once cured onto its surface is designed to last the life of the bladder; its function is to protect the bladder against chemical and abrasive attack during its service life, this leads to an increased bladder life.

A bladder “start-up lubricant” is a coating that is applied to a new curing bladder prior to it being installed in a press to help provide additional slip to reduce slip related defects during the first few tires cured on it. Typically these “start-up lubricants” will survive on the surface of the bladder for a limited amount of cycles; however, they do not provide any protection against chemical and abrasive attack.

A bladder treatment is used when there is a specific objective to increase bladder life, especially where sulphur cracking is seen as an issue to overcome. Bladder treatments also assist in providing an underlying layer of slip that helps to reduce defects throughout the life of a curing bladder.

A bladder “start-up lubricant” is used as a general purpose aid to the start-up of new bladders, they help ensure good slip to help a new, and therefore stiffer, bladder comply to the contours of the inside of a tire, thus minimizing defects for the vital first few tires cured. However, they do not offer protection against chemical or abrasive attack, so their use does not lead to higher average bladder life in the way bladder treatments do.