Microprismatic sheets of white and fluorescent orange are the new black when it comes to construction barrels.
Technological advances related to retroreflectivity and fluorescence can make the traffic safety devices brighter and more noticeable from a greater distance.
That all translates into the chance to reduce work zones accidents for state departments of transportation (DOT), and to increase sales of sheeting with complex patterns of cube corners for businesses.
Mentor, Ohio-based Avery Dennison, which is No. 85 among North American film and sheet manufacturers in Plastics News' latest rankings, as well as Maplewood, Minn.-based 3M are among the top producers of the sheeting that improves the performance of polyethylene construction barrels.
Reflective surfaces borrow light from another source and shine. Retroreflective surfaces return a portion of the light to the source and shine brighter.
Avery Dennison has an engineered films division that sold an estimated $61 million of products last year. When it comes to construction barrels, the company is seeing two trends, Scott Chapman, global marketing communications manager of Reflective Solutions, said in an email. First, the end users are upgrading to microprismatic sheeting because it appears whiter by day and a brighter orange at night. And, they are asking for fluorescent orange instead of standard orange because it is more visible at low-light times of day like dusk and dawn and during poor weather.
While the qualities of microprismatic sheeting sound like a detergent ad extolling whiter whites and brighter colors, it's really about the safety of workers and drivers, according to manufacturers and the customers willing to pay more for it. Delineating work zones with devices that boost visibility around the clock is important to agencies as crews maintain roads at all hours, and the driving population ages and engages in activities like texting behind the wheel.
“In an era where many traffic engineers are worried about various forms of distracted driving and looking for any additional help to grab the attention of motorists, these improvements may deliver some help,” Chapman said.
The Michigan Department of Transportation is on track to become the 18th state to require microprismatic sheeting and fluorescent orange for its construction barrels, which now cost $51 to $85 each, even though the price would increase to $73 to $112 each. MDOT owns about 10,000 of the devices and contractors supply another 190,000 for road projects.
The price hike of 32 percent to 43 percent is justifiable when saving lives is on the line, according to Chris Brookes, an MDOT work zone engineer. He said in an email that work zone fatalities and injuries increased from 2013 to 2014 and that's a concern for the agency tasked with ensuring the public arrives safely to their destination, in addition to road construction and maintenance. Using fluorescent retroreflective sheeting on construction barrels should help drivers, he added.
“The result is drivers will spot the temporary work zone traffic control device sooner and will be able to begin reacting to tapers and traffic shifts earlier,” Brookes said. “The increased conspicuity and delineation should reduce crashes as well as injuries and fatalities in work zones.”
MDOT says a review of work zone crashes from 2010-14 shows 52 of the 107 fatalities and 2,239 of the 6,881 serious-injury accidents occurred during low-light conditions, including cloudy, rainy and foggy times.
“If one out of the 52 drivers that lost their life on Michigan roadways in a work zone had the additional sight distance to either avoid the crash or slow to a speed that allowed them to live, the program would be worth the change,” Brookes said.
Science behind safety
Historically, Chapman said the white bands of a construction barrel have been made of glass beaded or metalized prismatic sheeting, which gives them a gray day time color even though they reflect bright white at night.
“An improvement gaining popularity is the use of brighter, high-performance air-celled microprismatic sheetings,” Chapman said. “These offer a truer white color during the day, as well as appearing brighter at night.”
Bimal Thakkar, a 3M product developer and materials scientist, explained how it works.
“Light bends in glass or water,” Thakkar said in a telephone interview. “Now if you go from glass to air, it bends, too, but in the other direction and that allows at certain angles for light to come back to the source. Without the air cells the light wouldn't come back to the source.”
A product data sheet for Avery Dennison's microprismatic series used by barrel makers says it is produced with a high-gloss PVC and acrylic surface on a PET film. Chapman said the air cell layer is between the prismatic sheet and a sealing layer compared to single-layer sheeting, which uses a vapor coat of aluminum as the reflector.
“The air cell serves as a mirror,” he said. “For fluorescent orange to really stand out as brilliant and catch your attention, it needs the air cell construction. Otherwise, the gray aluminum layer partially negates the strong fluorescent appearance.”
The use of fluorescent orange bands on construction barrels follows a trend started with road signs. Not only is it brighter at night, the improved visibility at daybreak, twilight and inclement weather is beneficial “when motorists may not have turned on their headlights, or may be driving only with daytime running lights,” Chapman said.
3M researchers say they developed the system in the 1990s that solved the fading problem associated with fluorescent colors and allowed for their use in traffic control devices. Another innovation: No solvents are used to make the company's materials, Thakkar said.
“Our old technology was very solvent intensive and took a number of steps and essentially we had to burn off the solvents. We couldn't reuse them,” he said. “The prismatic products you see on the road now are made completely solvent free. In terms of a green technology perspective, I feel being part of that was a pretty good accomplishment — to make a product that's better from the consumer perspective plus it's better for the environment.”
In the zone
3M combines its fluorescent colors with its microprismatic sheeting in its Diamond Grade product line, which it promotes as having “unmatched” adhesion to withstand the knocks of a work zone as well as a top protective layer that resists cleaning solvents.
The company offers presentation tools to DOTs looking at changing the specifications for barrels they buy. Agencies also can refer to a product guide — just a partial list and not an endorsement — put out by the U.S. Federal Highway Administration, which names Nippon Carbide and Orafol Americas Inc. as other sheeting manufacturers.
Seventeen DOTs require the fluorescent microprismatic sheeting on construction drums, according to Fanna Haile-Selassie, media relations manager for 3M. She said she couldn't disclose how many more states are considering the changeover.
The Virginia Department of Transportation converted to the new specification after a three-year phase-in period for barrel makers to handle the logistics of the change. The agency believes the “gained defensive driving cues” will lower the crash rate in work zones and avoid property damage, injury and perhaps save lives, a state report says. In 2013, 17 people died in work zone traffic crashes in Virginia, according to the National Highway Traffic Safety Administration. Across the United States, there were 579 fatalities.
The VDOT report says the state expected to see a cost increase of about 30 percent per construction barrel but the benefits should outweigh the added expense as the U.S. population ages. VDOT points to a statistic that says a 59-year-old driver needs eight times more light than a 20-year-old to see the same object while driving.
“By 2020, about one-fifth of the U.S. population will be 65 years of age or older,” the report says.
It also notes that Virginia work zones will be consistent with Maryland and West Virginia. In the Midwest, MDOT officials say Illinois, Wisconsin and Minnesota already have made the change.
Orange to green
Microprismatic sheeting falls under 3M's business segment called “safety and graphics.” The segment is a distant second in the $31.8 billion company's five revenue-producing units — industrial tapes is first — and it made up 22.6 percent of 3M sales in 2014.
Net sales for the unit came in at $5.7 billion and operating profit at $1.29 billion, which was a 5.6 percent increase over 2013. Of those sales, the traffic safety and security business totaled $1.5 billion with Diamond grade sheeting being a market leader, according to Frank Little, 3M's executive vice president of safety and graphics.
Helping government customers improve traffic safety and public security is a $20 billion market opportunity, Little told investors and analysts last December during a presentation about the outlook for 2015. 3M is well positioned to capitalize on the “sizeable growing safety regulation trend” around the world, he also said, showing a map with North America, Western Europe and Australia shaded green.
“Green represents strong regulations and enforcement, many of which 3M was vitally involved in consultative manner in establishing,” Little said, adding that company employees are “industry-leading consultants” to regulatory agencies.
Worldwide, 3M says more than 1 million people die annually in traffic crashes with 92 percent of the deaths happening in developing countries, which Little said are in the early stage of establishing higher standards and regulations.
“We continue to invest in our significant global expertise and resources supporting this trend as we work to make the world a safer place,” Little said.
Some of the investment is happening in Brownwood, Texas, where 3M is getting ready to ramp up production of microprismatic sheeting, according to local officials. In late August, they approved incentive grants for two projects at the 3M plant there. One of the projects calls for investing $6 million in new equipment and employees to develop advanced engineer grade prismatic sheeting but no specifics were given about its application.