How Tires are Manufactured

There are many steps in the tire manufacturing process.  Specialty Tires of America takes raw materials, rubber and various compounds and additives depending on the specification of the tire, to complete the finished product. 

Natural rubber from the rubber tree or manmade synthetic rubber is combined, in the Mixing Department, with oil and carbon to form batches of rubber to be used in the manufacturing process.   

It is also a science!  Samples of mixed rubbers are taken at various stages of the manufacturing process to ensure specifications are being met.  We have a lab of technicians that ensure the properties of the rubber, such as hardness, abrasion resistance or stretch is met. 

Two Types of Tires

The two types of tires that we produce are radial tires and bias ply tires.  Radial tires are what we run on our cars and trucks on the roads today.  The benefit of a radial tires is the smooth ride, fuel economy and lower rolling resistance.  Radial tires are produced in two stages.  The first stage, the carcass is made, in the second stage the tread package is applied. 

Bias ply tires are a sturdy tire that is used for heavy applications like tractor tires, underground mining tires and sand tires just to name a few.  For this application, a rubber wrapped corded fabric is applied in layers.  While the radial cord goes straight across the tire from bead to bead, the bias tire fabric is cut at an angle and goes diagonally across the tires with the additional plies crossing in an X pattern.  These tires are best used in off road and severe service applications. 

Our bias tire builders assemble a complete green tire.  Green tires are not green.  We consider them green because they are in a pre-cured state.  They take plies, beads, sidewall rubber strips and treads to assemble the green tire.  Beads are high tensile hoops of rubber wire strands that is used to mount a finished tire on a rim.  After assembly, they do not look like what you would consider a tire, they appear to be a long cylinder tube that have an opening on each end. 

The process of taking a green tire to a finished tire is called curing.  We use steam and heat to cure a tire.  Depending on the type of tire being produced, a mold is placed in the curing press.  The mold includes the tread pattern and sidewall stamping of items such as the name, the brand, size and warnings.  The mold cavity is in the shape of a finished tire. 

After the curing steps, the tire goes to the Final Finish Department, where the tire is inspected, measured, and checked for uniformity and given final touches.  The final touches included buffing, logo application, and protective wrapping.  The tires are then headed for shipping to our customers. 

Courtesy: Kathleen Mumau | Specialty Tires of America | https://www.stausaonline.com/