Curing Bladders

The Criteria for Choosing a Bladder

• The bladders are made of butyl rubber
• The dimensions and geometry of the tire to be cured determine the
bladder to be chosen for the job.
• Stretching occurs during the curing process both in radial and
circumferential directions.
• The stretching ratio of the bladder should be kept in balance.

• Too big an elongation not only shortens the service life of the bladder,but it
may also lead to an irregular elongation of the tire, which may cause the
tire to become asymmetric in shape.
• Too small an elongationmay cause wrinkles to the bladder, which in turn will
cause damage in the inner surface of the tire.
• The service life of a bladder depends on the elongation, bladder material,
curing temperature and pressure used.

Functions of a Good Bladder

Good Air / steam / water impermeability
Good Heat transfer
Capable of retaining high pressure
High degree of flexibility
High degree of resistance to growth