Rafael Vargas Ph.D.
Rafael Vargas helps get you to work everyday.
Vargas, a Ph.D., is the Lead Scientist for the Analytical and Materials Analysis Laboratories at Birla Carbon. And the Marietta, Georgia-based company’s world revolves around carbon black.
Carbon black is a unique substance. Manufacturers make it through the partial combustion or thermal decomposition of gaseous or liquid hydrocarbons. Its physical appearance is that of a black, finely divided pellet or powder.
Many applications depend on carbon black. None is more important in its use in the tires on your vehicle. Carbon black makes up about 40 percent of your tire’s composition by weight, with rubber accounting for most of the balance.
Carbon black has many properties, depending on how it’s manufactured. For tires, it improves tread wear, reduces rolling resistance and maintains traction.
“About 150 years ago, someone discovered if you combine carbon black with rubber, you can actually toughen that rubber,” Vargas said. “There's special relationship between the two materials and hence, now we have black tires for many, many years.”
Vargas is a senior scientist with Birla Carbon, where he’s been for nine years. His role has gone through a transformation.
“When I joined Birla Carbon, I actually managed a laboratory,” he said. “So my role was to supervise five chemists to do all this testing and method development.”
That technology laboratory does mostly assessments of products, quality control, new product development, and addresses health and safety and environmental issues.
More recently, the company moved into some new products, other carbon containing materials besides carbon black. The company needed to do some new science.
Vargas took on the role as lead scientist, where he gets to focus on developing new products and processes as opposed to the managing the day to day running of the technology laboratory.
“I'm the subject matter expert,” Vargas said. “The go-to guy on how to make things work and figure out what testing is needed.”
About 80% of the volume of the material Birla Carbon produces goes into tires. Another portion goes into other rubber products. The rest goes into coatings, inks and plastics as well as some electrical applications.
Those applications include:
All those applications demand different properties from the carbon black. It’s a toughening agent in tires, so the rubber can remain elastic yet it also becomes a lot more durable.
“If you just had a tire made of rubber and it didn't have any carbon black in it, it would probably only last a thousand miles before it fell apart,” Vargas said. “Whereas when you cure the rubber with carbon black present, now the tire can go a hundred thousand miles because it's much tougher, more durable product. It's what we call a reinforcing filler.”
And that shiny black sports car you admired the other day? It uses carbon black as a pigment in its finish. “It’s a material that would make the black paint job very black,” Vargas said. “It's not just going to be black, it's going to be a really deep jet black. It's going to have a nice bluish undertone. And the material is also going to be flawless because you can't have any other materials in it.”
In fact, carbon black is used if you're trying to put black into any material to help protect it from the ultra violet rays of the sun. Trash bags have carbon black in to give it its opacity and UV protection. It only takes about a 1 or 2 percent of carbon black as an additive to get that black color.
Vargas said that practically anything you see as black contains carbon black. That includes many computer parts like your keyboard and the frame of your monitor. It all contains carbon black in the plastic.
Manufacturers of overhead power lines coat it in a black rubber containing carbon black. That black is there to protect the insulation from breaking down from the UV rays of the sun.
Carbon black is conductive. With the right structure, it can add conductivity to materials.
“In a tire, you may want that rubber to have a little bit of conductivity if you're trying disperse static electricity,” Vargas said.
Battery manufacturers use carbon black as electrodes, due to its conductivity properties.
A typical passenger tire may have up to 16 different types of carbon black, each manufactured with slightly different properties. One goes into the tread of the tire to make it hard and durable. And there's one that goes into the sidewall of the tire to maintain its flexibility.
Carbon black has different structures, particle sizes and surface areas to achieve its various properties. The carbon black that goes into a tread has a minimal structure. The one that goes into the sidewall of the tire has a lot of structure.
“If you imagine a bunch of grapes, a bunch of balls connected by arms and legs into a cluster. That's what a carbon black aggregate looks like. So the more structure, the more arms and leg, then the different performance you'll get out of the carbon black,” he said.
And since carbon black is 99 percent carbon, it's not going to oxidize or react easily.
“It's pretty inert material,” Vargas said.
Rafael Vargas, Ph.D. in his Birla Carbon technology lab with a HORIBA Ultima Expert ICP-OES
Oil is the raw material used to make carbon black. That oil must be tested for impurities, measured in the parts per million, that could interfere with the eventual production output of the carbon black.
The Birla Carbon lab uses a HORIBA Ultima Expert ICP-OES (inductively coupled plasma optical emission spectrometer). The instrument features high resolution, high sensitivity and high stability. It’s used for the determination of metal content in raw materials and quality control of its finished product.
Birla Carbon uses the Ultima Expert for both monitoring the properties of raw materials it receives and for quality control of its carbon black production.
Birla Carbon also uses HORIBA’s EMGA-920 for oxygen and nitrogen analysis in their products. Those elements are not possible to measure with ICP.
Finally, Birla Carbon’s technology lab uses HORIBA’s Partica LA-960 Particle Size Analyzer laser scattering particle size distribution analyzer.
Without carbon black, the world would be a lot more expensive, Vargas said.
“Our rubber goods wouldn't last as long,” he said. And when you want a tire to have minimal rolling resistance, you will also save fuel.”
HORIBA’s EMGA-920 oxygen/nitrogen analyzer
HORIBA’s Partica LA-960 Particle Size Analyzer
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