Coatings & Coverings

Rubber - what is it?


Each rubber is mixed from a big number of different ingredients.
Let's take a popular example to explain the process.

Here is information on how to make tires.
This is for educational purpose only. Please do not try this at home. Any rubber formulation is a closely guarded secret so please do not write to us to elaborate. 


INGREDIENTS:
1) Polymers:
You start with SBR, EPDM, polybutadine. These synthetic polymers are superior than natural rubber. They are flexible yet strong. They give adhesion yet yields long-life. SBR is the most commonly used polymer for car tires for its relative economy. (Well, it's the cheapest polymer thus far)
2) Fillers:
You add cheaper fillers to expensive polymers. The fillers reinforces the polymers by adding strength and improved mechanical properties. Use carbon black, silica, clay, titanium oxide. When someone does a burn-out or leaves a skid mark, you will notice that it's a long strip of black patch. You are seeing carbon black. Try using nano-carbon, or nano-titanium oxide and you get to brag you are riding on nano-tires.
3) Softeners:
As the name indicates they control stiffness of the mixture and add increased processability. Use hydrocarbon oil, resins.
4) Antidegradants: It protects against heat, oxygen, ozone… Use para-phenylenediamine. Sometime these are called anti-oxidants, not to be confused with anit-ozonates. It has a side benefit of lubricating the mixture.
5) Curatives:
Cures the soft polymers into tough yet elastic compound. Use sulfur, sulfemamides.
6) Activators: They aid curatives to do their job more effectively. Use zinc oxide, stearic acid.


Of course, the modern tires are usually radial in construction (nylon or steel belted) so that's another layer of science which we will not cover here. Unlike the tires on the family sedan, racing tires aren't made to last much longer than one tank of gas. Counting practice, qualifying and the race, teams went through as many as 15 sets of tires during the racing weekend at Atlanta, proving again it's tires that make the NASCAR Nextel Cup Series go 'round.
"To most teams, tires are an expendable commodity," said Chad Fletcher, marking manager for NASCAR at the Goodyear Tire and Rubber Co. "It's the cheapest way to go fast."