Recycled resin is fit to be (railroad) ties 

March 13, 2024
Granite Peak Plastics pours its PE and PP into durable Triton Ties, which can last 50 years. 

From the Spring 2024 issue of Plastics Recycling.

By Ron Shinn 

Granite Peak Plastics in St. Louis plans to drastically change the form of the recycled resin it now ships in super sacks. All of the polyethylene (PE) resin it produces will eventually go out the door as Triton Ties, a new line of fiber-reinforced recycled polymer composite railroad ties. 

The transition exemplifies CEO Greg Janson’s philosophy of buying plastic by the pound and selling it by the part. 

“When you look at the companies that buy scrap and sell pellets or regrind, you see there are a lot of ups and downs in that business,” says Janson, who is president of Granite Peak Plastics and Triton Ties, a sister company formed to manufacture and sell railroad ties. “A lot of companies have come in and gone out of business.” 

“We looked at the landscape and noticed the common denominator among the successful players was that some or all of the material they were buying was going into a product they were making,” Janson says. “They were not just simply sorting it and changing it into a different form.” 

Janson points to KW Plastics in Troy, Alabama, which molds some of the PE it recycles into paint cans; Advanced Drainage Systems in Hilliard, Ohio, which recycles huge amounts of PE and other material for its water-management systems; Trex, in Winchester, Virginia, which recycles bales of film for its plastic lumber; and carpet manufacturers that are buying bales of (polyethylene terephthalate) PET to turn into new carpet. 

“Composite railroad ties are one of those rare products that is good for the environment and good for the planet long-term, and they are good for the bottom line,” Janson says. “Replacing wood that you have to replace every 10 years to 15 years with composites that last for 40 years to 50 years will save billions of dollars for the railroads over the life of the composites.”  

Triton Ties are not the first plastic railroad tie. Earlier companies tried to create plastic ties that competed with traditional wood ties on price. 

In 2017, Janson co-founded a company called Evertrak and developed a glass-fiber-reinforced tie using recycled plastic that competed with wood on performance, not price. It outlasts wood ties and is currently being sold to railroads for replacement ties. 

“We decided that if it doesn’t work properly, it doesn’t matter how cheap the product is,” Janson says, describing the development of the Evertrak tie. “We needed to make a tie that works and put it in specific applications where it is going to have a life cycle that benefits the customer.”  

Janson sold his stake in Evertrak in 2019, and after a three-year non-compete agreement expired in December 2022, he introduced Triton Ties.  

Granite Peak Plastics has three lines in its St. Louis plant: a wash line that handles bulky rigid PE and polypropylene (PP) with metal contamination; a post-commercial line that runs the cleaner material that does not need to be washed, such as pallets; and a reprocessing line to make PP and PE reprocessed material from super sacks, non-wovens, regrind and flake. 

The company has 37 employees and operates three shifts, five days a week. The same staff operates the Triton Ties production line in a building next door to the recycling plant. 

Triton Ties are made from low-density PE, high-density PE and PP, plus glass-fiber reinforcement and other additives. The blend is proprietary. But Janson says the company is highly focused on the precise measurement of everything that goes into the tie. 

To manufacture Triton Ties, Janson purchased two twin-screw extruders from Austrian machinery builder MAS. He opted for twin-screw extruders because the gentler mixing and wider options for introducing additives that twin-screw machines provide helps maintain the integrity of the glass-fiber reinforcing agent. Single-screw extruders require mixing all components of the recipe before they go into the extruder. They also generate more heat, which can degrade the reinforcing agent. 

“We have a very thorough mixing process that ensures consistent performance,” Janson says.  

The recycled plastic and some additives go into the first extruder where they are blended. The plasticized material then goes to the second extruder, where the glass fiber is added. 

Automated feeders are used to provide precision inputs. 

Janson says that adding the glass fiber as one of the last steps means it does not get broken as much and less is needed to achieve the necessary strength. 

The material that comes out of the second extruder is dumped into a large-cavity mold where a small amount of pressure is applied. Janson says the extruder generates enough pressure to fill the mold. 

Triton Ties has a bank of molds with cooling water jackets. Cold water circulates from a chiller throughout the bank of molds. An 8-foot, 6-inch long mold takes about five minutes to fill with approximately 200 pounds of material that includes about 170 pounds of recycled plastic and 30 pounds of fillers and additives. The tie then needs about one hour to cool. With a bank of 12 molds, one tie is being removed from a mold as another mold is being filled.  

Each tie passes through an X-ray after it comes out of the mold to look for voids and any other imperfections. They also pass through a robotic texturing station to add surface texture that helps the tie grip the roadbed. 

Triton Ties are shipped from the plant by rail. 

Janson says Triton Ties are a highly engineered product. “They are engineered for the long haul, and I really feel we have a product that is engineered up to the standards our customers deserve.”  

Composite ties are more expensive than wood ties. But that is only part of the equation. 

“Let’s say a composite tie costs $150 and a wood tie costs $80,” Janson says. “Regardless of whether it is wood or composite, there is about $100 in operational expense to install it. So, it is really $250 versus $180 to install one tie in the track. 

“If you have a wood tie that lasts 15 years and then you have to pull it out and put another one in, now it is another $180 and you are at $360 compared with the $250 for the recycled tie that is going to last 50 years,” Janson says. “One more cycle for the wood tie and the railroad has spent $540 compared to $250 for the composite tie.” 

Janson estimates there are more than 160,000 miles of track in the U.S., requiring that 25 million ties be replaced every year. Composite Triton Ties can be substituted directly for wood ties. 

“There are applications where composite ties make more sense than others,” he says. “If you are in a dry environment, wood ties are going to last a lot longer so it will be difficult to make an economic argument for a composite tie. 

“But if you are in a high moisture environment, where there is a lot of rot, you get a lot of termite and insect infestation. Then it makes a lot of sense to use a composite tie.”  

The southern crescent of the U.S., where about 5 million railroad ties a year are replaced, is a target market for Triton Ties. 

Wood railroad ties have traditionally been made from oak. However, ties were made in the past from 150-year-old trees, which are no longer available. Railroads say 40- to 50-year-old oak now available is not as hard. 

To slow down rotting, wood ties are soaked in creosote, which can be harmful to the environment. 

Janson says some wood ties in coastal areas in the South sometimes have to be replaced after just six years. 

Triton Ties are now on sale and are being tested by several railroad companies. “We have ties available and have completed all our third-party testing,” Janson says. “We are actively supplying test sites.” 

In the meantime, the MAS extruders, laser filter and pelletizing equipment purchased to manufacture railroad ties are doing double-duty in recycled PP pellet production. The system can easily switch from making pellets to feeding the railroad tie molds.  

“We can also now do some compounding,” Janson says. 

Being vertically integrated so that Granite Peak Plastics can produce all the recycled resin Triton Ties needs is an advantage, Janson says. “We feel we have a great handle on our supply chain.” 

Companies have tried unsuccessfully for 20 years or more to make non-wood ties. The experience means today’s manufacturers must overcome a legacy of failure. 

“The only thing we don’t want is for somebody to put a bad product on the market,” Janson says. “What we are battling now is some of the past performance of composite ties. 

“We are being successful at changing those opinions,” he says. “It’s kind of where we have to start.” 

He says some companies in the past were not careful about the types of plastic they were using. “They would just grind up whatever they had and put it in there,” he says. That led to product inconsistencies and failures. 

“From an engineering standpoint, I am not sure railroad ties have been taken seriously enough over the years,” he says. 

The Granite Peak Group has a 28-acre site in St. Louis where Janson plans to break ground for a new campus in 2025. The goal is to build a plant that recycles 85 million pounds of plastic a year and produces 500,000 Triton Ties a year. While Granite Peak Plastics expects all of its PE to eventually go into railroad ties, it will continue to sell the PP it recycles. 

“When the operation scales up to a half-million ties annually, we anticipate being able to feed the majority of that with our own operation and from buying regrind from the market,” Janson says. “We will be very focused on buying post-commercial regrind and always using recycled plastic.” 

One mile of track needs about 3,240 ties, Janson says. That adds up to 275 tons of recycled plastic if all 3,240 are Triton Ties. 

“That’s 275 tons of plastic diverted from disposal, and you are saving 7,400 gallons of creosote from being used,” Janson says. “That also means you do not need to cut down 800 hardwood trees, and those hardwood trees will be able to continue to absorb 16 tons of CO2.” 

Janson says Granite Peak Plastics employees take pride in producing a new product that is good for the environment. “They like the fact that we are keeping plastic out of the ocean,” he says. “They also understand the importance of having a consistent market for our product and what it means for their job security.” 


Granite Peak Plastics, St. Louis, Missouri, 314-963-8000,, 

About the Author

Ron Shinn | Editor

Editor Ron Shinn is a co-founder of Plastics Machinery & Manufacturing and has been covering the plastics industry for more than 35 years. He leads the editorial team, directs coverage and sets the editorial calendar. He also writes features, including the Talking Points column and On the Factory Floor, and covers recycling and sustainability for PMM and Plastics Recycling.