Mixed Signals

The popularity of commingled collection has left glass recyclers seeking end markets beyond traditional food and beverage containers, for which the purity of the cullet is essential. Mixed cullet, the problematic understudy for wholesome clear cullet, is finding its talents better suited to the grittier roles of abrasives and aggregate substitutes.

Comingling with Contaminants

Liz Citrino, president of the California Resource Recovery Association, Sacramento, says collecting enough glass to support the glass recycling infrastructure is not a problem; collecting enough quality glass is.

“I think that as there’s increasing regulatory pressure on jurisdictions to collect large quantities of materials,” she says. “We’ve seen a lot of urban areas shift to commingled programs, which has certainly affected the quality and level of contamination and the color-mixing in glass.”

Citrino, who is from a rural area of Humboldt County, supports source-separated collection, “because the only way we can afford to collect and ship our materials is by maintaining the highest quality possible.”

Frank Nolan, plant manager of NexCycle, Inc., Syracuse, N.Y., says commingled collection leads to more color mixing and smaller pieces, making contamination difficult to eliminate.

Joe Cattaneo, executive vice president of the Glass Packaging Institute (GPI), Washington, also finds mainstreaming of commingled collections affecting the quality of the glass collected for recycling, therefore affecting what the MRFs pass along to processors.

Cattaneo says the value of cullet versus raw materials is similar within the glass container industry, and unless a manufacturer can secure a steady-stream of cullet, the incentive for using it in place of virgin materials is slight. “In a glass container manufacturing furnace, you can’t add cullet in one day and then go to virgin materials the next day.” To do so would require completely cleaning out the furnace, he explains.

Plagued by Plastic

It’s doubtful glass can regain its once prominent place in food and beverage packaging. Citrino finds it hard to imagine that in a period of increasing fuel costs a heavier material like glass will regain market share over the lighter plastic. “Nobody denies that that’s where plastic has its advantage.” Citrino says refillable containers and more localized distribution systems are necessary to the growth of glass packaging. “I think that there is certainly growing consumer support for those kinds of things, particularly refillable containers. I think the fact that they have pretty effective systems for refillables in Europe and Canada would argue that it is not that unreasonable of a goal.”

Cattaneo says, “It’s obvious to see that there’s more plastic packaging in the marketplace, and that definitely has an impact on our markets as well as the aluminum and steel markets that make packaging for food and beverages and other types of product lines. And we see a trend, of course, that plastic can emulate the shape and size of glass, and it doesn’t break. But, it’s still plastic, and it’s made of chemicals versus inert soda ash, sand and limestone.”

Clear Cullet: The Shining Star?

Clear cullet still reigns, as food and beverage container manufacturers comprise the leading end market for recycled glass.

“If we’re making the point that the product with the greatest market value is more desirable for recyclers,” Citrino says, “then certainly clear glass supports that argument.

“For example, in Humboldt County we have a small glass re-manufacturing business called Fire and Light, which makes high-end dinnerware from glass collected right here in Humboldt County,” Citrino says. “And in terms of the quality control of their product, their demand is obviously for clear glass. I think that small, specialty, high-value markets will probably always lean toward clear glass. On the other hand, finding markets that can use a mixed-glass or a color-mixed product probably are critical to being able to support the quantity of glass that needs to be collected in urban areas.”

Sorted amber cullet is also desirable, as beer bottles make up 49% of the glass container line, Cattaneo notes.

Nolan says, “Amber and clear glass are more marketable; there are more buyers in the U.S.” NexCycle processes glass for use by food and beverage container manufacturers. Each of his customer’s specifications varies to a small degree, he says.

Clear glass isn’t suited to every recycling application, however. Bill Brock, Environmental Recycling Center manager for Abilene, Texas, prefers brown and green glass, which gives him more “solid stuff” to use in roadway flex base. Brock’s Second Sand is also used in golf course sand traps, leach fields and in the manufacturing of paving stones.

The glass is color-separated at community drop-off sites, should Brock receive a request from a particular market. Rather than cleaning the glass when it comes into the MRF, he says, “you can just pulverize it and get it right out there on the roadway. No one sees it. The quality [of the glass] doesn’t matter.”

Brock believes great opportunities exist for communities with one central hub where glass is pulverized and then used in flex base, and that it’s just a matter of convincing the parties concerned that glass is a viable aggregate substitute. “You can save a good 12% of your bill by using glass.”

Cattaneo says, “More and more, we’re seeing the glass processors, the benefactors who buy the cullet from the MRFs, selling to other end-use markets beside the container market. And you’ll be seeing a lot more of that in the future, because when the specs for container glass are so tight, they have to look for other uses for it.”

Cattaneo says other suitable applications include tiles, abrasives for sand blasting, glasphalt (in which the glass in mixed with asphalt and used in road surfaces), bead manufacturing (for use in the reflective stripes on roadways) and as frictionators in matches and bullets.

Currently, according to the GPI's Web site, fiberglass manufacturing consumes the second highest volume of recycled glass. However, specifications for product consistency and quality are also high in that application.

As for mixed cullet destinations, Nolan says the Eastern U.S. has few. Although he sees new market opportunities for mixed cullet, Nolan believes entering them can be difficult. “Like anything else, there is a resistance to change. Also, you need to work with new customers to make sure your product meets their specifications.”

Ceasing Collection

As recently demonstrated by the City Council of Springfield, Ill., some municipalities may cut glass from curbside collections. In November, the council voted against paying Lake Area Disposal Services, Inc., to begin accepting clear glass from residential customers.

Cattaneo fears the elimination of glass from curbside collections will become more widespread if the “collection doesn’t warrant the price.” He says haulers may ask municipal programs to remove glass from the recycling stream because it isn't as profitable as the other commodities collected. “A lot of haulers that have recycling contracts also own landfills, so they get it both ways—meaning they will get the price either for the recyclable or get the price back by dumping.”

Brock says many smaller communities around Abilene would have dropped their glass programs if not for his product. “They would have just gone back to landfilling all of that. They get contaminated loads and commingled stuff, and they can’t meet market demands,” Brock says. “But it’s wide open for us.”

However, Citrino doesn’t think California municipalities are likely to drop glass from the recycling stream. “I think that in most areas, at least in California, municipal governments and haulers have built pretty mutually supportive relationships, because they are both charged with the responsibility for making recycling work,” Citrino says. “I think the bigger issue is when supply overwhelms demand, who picks up the additional cost of making sure that recycling keeps happening?”

Citrino thinks the success of such programs depends on public commitment from consumers, agencies and businesses, and on the creativity of everyone involved in looking for appropriate applications for all materials that are collected.

The compromised quality of glass from single-stream collections makes one thing clear: If mixed cullet is gaining in availability, processors need to explore end markets capable of absorbing the supply. Maybe mixed cullet can surpass its role as understudy to steal the scene after all.

Recycling Today staff member DeAnne Toto can be contacted via e-mail at dtoto@recyclingtoday.com.