Better for the Environment, Better for the Bottom Line

L.B. Foster Pueblo found that removing trichloroethylene from its manufacturing process not only eliminated a nasty environmental hazard but also boosted quality and cut costs.

When you're cutting, grinding, drilling and welding 4,000-pound pieces of steel rail, you can't avoid getting your hands a little dirty. But exposure to dangerous chemicals has no place in any workplace -- dirty job or not.

That's the belief of the management team at L.B. Foster's Pueblo, Colo., facility, which makes insulated rail joints for Union Pacific, BNSF and other rail companies. L.B. Foster's Pueblo plant is a 2011 IndustryWeek Best Plants winner.

Insulated rail joints serve as the central nervous system of railroad lines, preventing electrical current from flowing between the ends of two adjoining rails. When a train passes over a joint, the train's wheels complete the electrical circuit -- enabling rail operators to know the precise location of trains within complex railways, and triggering crossing signals when a train approaches a road crossing.

In the manufacturing process, L.B. Foster team members receive 80-foot pieces of steel rail, cut them in half and create electrical discontinuity by placing an insulating material (Kevlar) between the two halves. Then they strengthen the joint by adding a support bar, and bind all the components in place with an epoxy.

For decades, it was an established industry practice to clean and degrease the rail parts prior to assembly by using a chemical called trichloroethylene. Several years ago, however, plant manager Bart Peterson and other company officials began a design-of-experiments protocol to determine if trichloroethylene -- which has been linked to several types of cancer -- could be eliminated from the manufacturing process.

"We were concerned about trichlor for two reasons: safety for the guys -- trichlor is a nasty chemical to be inhaling and absorbing through your skin -- and then the environmental aspects, the disposal of the rags and everything else," Peterson says.

At first, there was some concern that removing the chemical from the manufacturing process would compromise the integrity of the "almost weld-strength bonded joint," explains Steve Burgess, L.B. Foster's director of continuous improvement.

"And that's where we used the design of experiments to test the various factors to see which ones were significant, and whether or not the trichloroethylene was a significant factor or not," Burgess says.

With the help of a major customer, the team from L.B. Foster came up with 32 different test factors and eventually narrowed them down "to our final full validation runs of six critically deemed factors," Burgess explains.

The results showed no significant loss of bond strength when the rail joint was assembled without the use of trichloroethylene as a cleaning agent.

"And 20 or 30 years of belief in a particular concept was swept away," says Sid Shue, general manager, L.B. Foster Allegheny Rail Products, who was involved in the testing process.

In fact, the process revealed that using trichloroethylene to clean the rail parts "was actually deleterious" to the bond, Shue explains.

"By flooding the material with this solvent, we were actually getting too much into it," Shue says. "It was absorbing into the surface, getting trapped and making the bond weaker -- not stronger."

The L.B. Foster team suspects that the trichloroethylene was evaporating and releasing gases inside the pores of the steel, which weakened the bond by hindering the epoxy from reaching all the cracks and crevasses of the joints and bars.

But, "We can't substantiate it beyond a reasonable doubt," Peterson adds.

Today, workers use a high-pressure air nozzle to remove large particles of dust and dirt from the steel. Then, just prior to assembly, they wipe it with a lint-free rag.

Regardless of why the chemical was compromising the integrity of the bond, the benefits of eliminating trichloroethylene from the plant's manufacturing process are undeniable -- and quantifiable.

Since eliminating trichloroethylene, internal and external testing shows that the shear strength of the rail-joint bond has improved by 400 psi, Peterson notes.

Taking trichloroethylene out of the process also has reduced the plant's hazardous-waste releases by 99%.

And then there's the impact to the bottom line. When the plant was using trichloroethylene, it was going through one 55-gallon drum of the chemical every month -- at a cost of approximately $2,000 per drum.

In 2009, L.B. Foster Pueblo used 3,300 pounds of trichloroethylene. Today, it uses none.

"It was a good change for us," Peterson concludes.

See Also:

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish